Proof of logic [Archive]

Complexity

15th September 2007, 08:22 PM

Proof of logic....well, here's my take on it:

In the end, logic and math are pseudosciences. Very good ones, but still pseudosciences, because they base all of their claims on intuition. Now, they don't have to. They could (and probably will in future) derive the rules, etc. from human psychology or some similar source. Math and logic are needed to do this, however, so for now we have to stick with intuitive rules (which happen to be quite good and quite complex).

I don't regard math or logic as sciences at all, let alone 'pseudosciences'.

I've addressed this in earlier threads and won't rehash it here.

Math is the study of consequences. The axioms that are posited do not need to have any consistency with reality as we know it - the only requirement is that they be consistent as a set of axioms.

Drop the term 'pseudosciences' - it adds nothing to the discussion, and is likely to be misunderstood as woo.

TuftedPuffin

15th September 2007, 08:40 PM

I don't regard math or logic as sciences at all, let alone 'pseudosciences'.

I've addressed this in earlier threads and won't rehash it here.

Math is the study of consequences. The axioms that are posited do not need to have any consistency with reality as we know it - the only requirement is that they be consistent as a set of axioms.

Drop the term 'pseudosciences' - it adds nothing to the discussion, and is likely to be misunderstood as woo.

In this case, woo was kinda the comparison I was making, though I agree that there are huge differences.

Math is the study of consequences, but it also makes claims. For example, the real number system is presented as equivalent to our intuitive concepts of number. The consequences are the rigorous stuff, but the choice of axioms is often based on achieving some "real world result", despite the fact that math alone can't judge whether the result accords with the real world. That's why I compare math to pseudoscience.

Complexity

15th September 2007, 09:18 PM

What does it fail to capture?

What is incompleteness if not asking meaningless symbols to be meaningful and then asking them what their meaning is?

I'll use 'iff' as an abbreviation for 'if and only if'

We're working with statements - strings of symbols that are considered to be 'well-formed' if they conform to a specified grammar. One such grammar is that of the first-order predicate calculus; another is that of the second-order predicate calculus. More on these later.

An interpretation of a statement or a set of statements provides meaning to the symbols in the statement(s). For every interpretation of a set of statements, each statement in the system is either true or false under that interpretation.

A statement that is true under every interpretation of the system is called a tautology.

A statement that is false under every interpretation of the system is called a contradiction.

A set of statements is consistent if it they don't imply a contradiction.

Pick a consistent set of well-formed statements and assume that they are true. This set is our set of axioms.

Some statements may exist that are true iff each of the axioms is true (under interpretation). These statements are called consequences of the set of axioms. These statements are also called theorems.

A set of axioms and the set of its theorems are called a theory.

Another important idea, besides consequence, is that of derivability.

A logical calulus is a set of procedures, a logical machine, for taking one or more statements and constructing new statements. It also provides the grammar that statements must conform to to be considered well-formed.

One such logical calculus is called the first-order predicate calculus (FOPC). Another logical calculus, the second-order predicate calculus (SOPC), enhances the first-order predicate calculus by adding in the ideas of 'for every' and 'there exists'.

Whenever we use the procedures of a logical calculus to construct a new statement from one or more existing 'input' statements, we say that we are deriving the new statement from the 'input' statements, and that the new statement is derived from the 'input' statements.

Which statements can we feed into the logical calculus machine? Any of the axioms and any statements which were derived from the axioms, directly or indirectly.

We will say that a statement is derivable iff there is a sequence of derivations that starts with the axioms and results in the construction of that statement.

A logical calculus is sound iff, for every set of axioms that conform to the calculus, every derivable statement is a consequence of that set of axioms.

In other words, given the input of axioms or theorems, a sound logical calculus can only construct theorems.

A logical calculus is complete iff, for every set of axioms that conform to the calculus, every theorem is derivable.

Goedel proved that the first-order predicate calculus is complete; that is, every true statement of a FOPC theory, every theorem, can be derived from its set of axioms. That impressed mathematicians.

Goedel then proved that the second-order predicate calculus is incomplete; that is, there exist SOPC theorems that can not be derived, statements that are true that can not be proved to be true.

Furthermore, Goedel proved that if you try to patch up the calculus so that this true statement becomes derivable, you inevitably result in a calculus that has other true statements that are not derivable. You can't ever, ever fix it. Any logical system of sufficient complexity has theorems that can't be proven.

This shocked the hell out of mathematicians.

I hope that this made some sense. I left out a lot and probably screwed something up.

cyborg

15th September 2007, 09:59 PM

This shocked the hell out of mathematicians.

I hope that this made some sense. I left out a lot and probably screwed something up.

Complexity - you think I don't understand this. I do. What I am trying to do is give the fundamental 'why' as to 'why we should not be shocked by this result' because to me it is not just correct: if you frame the problem in the correct way things being the other way would be just plain weird.

Mathematics is powerful enough to ask about its own 'meaning'. It does, however, remain totally meaningless.

1 does not have a meaning. 0 does not have a meaning. X does not have a meaning. Y does not have a meaning.

When you build a mathematics from these meaningless symbols and then assign meaning to them (from the human perspective) you can then ask questions which equate to shifting these symbols about until there is a result.

Building atop that you can build questions about questions. Once you do that you can ask: "Is the meaning of this statement correct?"

Whilst this is a well-formed question in our formal system it is as meaningless as the symbols that formed the system. The question cannot be answered - the meaning is arbitrary because the output symbols are just as meaningless as the input symbols. The only way you can recognise a 'meaning' is to attach a computation between these symbols. But there are an arbitrary number of ways of linking these symbols together. You are left then again being forced to recognise a 'meaning' in this and so on ad infinitum ad infinitum.

This is why Godel numbering is so clever - by expressing the computation in the same way he expressed the result he could produce the fundamental fallacy of thinking that one set of symbols was fundamentally 'meaningful'. By making it all numbers we are reduced to asking the absurd question:

"Is this set of numbers more meaningful then this set when they are the same set?"

The question is well-formed but meaning can only occur in a system with bias - the axioms. A formal system where symbols come together in purely arbitrary ways would be, I'm sure you'd agree, totally chaotic. But we are forced to make such arbitrary decisions in order to get 'meaning'.

I blame our brains for having this confusion about their own nature.

BTW what meaning do you think this set of symbols might have?

0Y1XY0X1XY0X1XY1XYXY1XYXYXYXY

And what about this set?

01XYXY11010X01X010XY1Y0XY1Y0Y1

In a way one might also say that the notion that such a thing as a formal system exists is the greatest fallacy of all...

Complexity

15th September 2007, 10:46 PM

Sigh.

Meaning is given to a theory through an interpretation. Many interpretations are usually possible.

At most levels of mathematics, mathematicians work with some interpretation (usually a common interpretation) in mind.

I have no idea what, if any, interpretation might be valid for your strings of symbols. You have provided no grammar.

I disagree with you about formal systems, of course.

Ichneumonwasp

15th September 2007, 11:02 PM

I don't think so.

Godel was about the impossibility of a system of logic that is inclusive of all truth.
Jetlag is asking about the actual rules of logic, or how you get from premises to conclusions.
Not that I understand why he asks such a question.

BJ

Um, no he's not. You may not be aware of his earlier posts in other threads. I was trying to help him out. Godel is what he is really asking about. He is trying to find room for God. Godel thought he had (or, at least room for the Platonic Forms).

He is really asking about the foundations and limitations of logic.

cyborg

15th September 2007, 11:03 PM

Meaning is given to a theory through an interpretation. Many interpretations are usually possible.

Yes.

So you're going to have to tell me: how does an interpreter prove its own validity in this case?

At most levels of mathematics, mathematicians work with some interpretation (usually a common interpretation) in mind.

Of course. There's no problem until you start interpreting interpreters.

I mean, I presume that you believe that the mind is isomorphic to some mathematical system, some style of computation?

I have no idea what, if any, interpretation might be valid for your strings of symbols. You have provided no grammar.

Exactly. But could you create one and would you find one grammar more meaningful than another? Why would you choose that grammar? Can the grammar absolutely justify this choice?

I disagree with you about formal systems, of course.

That formal systems exist?

Time to weigh the memes.

BillyJoe

16th September 2007, 12:00 AM

Um, no he's not. You may not be aware of his earlier posts in other threads. I was trying to help him out. Godel is what he is really asking about. He is trying to find room for God. Godel thought he had (or, at least room for the Platonic Forms).

He is really asking about the foundations and limitations of logic.

No, my first exposure to jetlag.
Now I understand why I didn't understand why he asked that question.
He was actually asking a different one.

JetLeg

16th September 2007, 02:25 AM

Yes.

If you knew anything about logic, you'd not need to frame such a question.

It's True! :)

Ok, please explain.

JetLeg

16th September 2007, 02:29 AM

Um, no he's not. You may not be aware of his earlier posts in other threads. I was trying to help him out. Godel is what he is really asking about. He is trying to find room for God. Godel thought he had (or, at least room for the Platonic Forms).

He is really asking about the foundations and limitations of logic.

Actually, I am much less sophisticated than that.

If you cannot prove logic, then how can you be so sure of it that you disprove god with it?

streamlet

16th September 2007, 03:15 AM

I'll take a stab at that.

Skeptics aren't saying, "We proved there is no god!" What people are saying is, "At this time, we have found no evidence of god that doesn't have another, simpler, explanation. This could change when new evidence appears."

BillyJoe

16th September 2007, 03:48 AM

Skeptics aren't saying, "We proved there is no god!" What people are saying is, "At this time, we have found no evidence of god that doesn't have another, simpler, explanation. This could change when new evidence appears."

Actually, some sceptics do say: "There is no god".
But, you are correct, what they actually mean is something like: "At this time, we have found no evidence of god that doesn't have another, simpler, explanation. This could change when new evidence appears."

cyborg

16th September 2007, 03:56 AM

If you cannot prove logic, then how can you be so sure of it

You're asking about two different types of certainty.

1) How can we be sure logic 'works' on a mechanical level? Because it's very simply constructable.
2) How can we be sure logic 'works' on an explicative level? Because we can make it reflect the world effectively.

that you disprove god with it?

You have to give 'god' meaning first, not ask us to remove meaning from it.

Ichneumonwasp

16th September 2007, 07:16 AM

Actually, I am much less sophisticated than that.

If you cannot prove logic, then how can you be so sure of it that you disprove god with it?

We cannot disprove God with or without logic. We can use logic and evidence to disprove certain views of God, but not views of God.

JetLeg

16th September 2007, 07:32 AM

You're asking about two different types of certainty.

1) How can we be sure logic 'works' on a mechanical level? Because it's very simply constructable.
2) How can we be sure logic 'works' on an explicative level? Because we can make it reflect the world effectively.

You have to give 'god' meaning first, not ask us to remove meaning from it.

'god' is usually said to be mysterious, unknowable, beyond human abilities to understand, so one should not really talk about the meaning I think, but -

'god' is more about attaching emotions to it, transcendent feelings, contemplations of the sacred, mystery and deep feelings...

cyborg

16th September 2007, 07:35 AM

'god' is usually said to be mysterious, unknowable, beyond human abilities to understand, so one cannot really talk about his meaning I think.

You use of language betrays you. You say it is mysterious, unknowable and so on then personify the thing you are talking about by calling it a 'him'.

'god' is more about attaching emotions to it, transcendent feelings, contemplations of the sacred, mystery and meaning of life...

Yes. Concepts attach themselves to other concepts.

Linking the concepts of 'god' and 'real' isn't meaningful if it is not knowable.

JetLeg

16th September 2007, 07:37 AM

I could actually call it a her, since it is more of an 'it'

cyborg

16th September 2007, 07:51 AM

You could call it anything you want - but the meaning you have arising from doing so is purely synthetic unless you can link it to something knowable.

slingblade

16th September 2007, 08:14 AM

Ok, please explain.

Not my job. You are able to educate yourself, as I educated myself. The fact that you asked a question out of ignorance, and that I chose to give a terse answer, in no way obligates me to you.

I chose to take an intro course in logic when I attended college a couple of years ago. Because of that course, I've done independent study in the subject, on my own. My life experience (48 years' worth), combined with my personal thought processes, have made it clear to me that my life is better with a grounding in logic than it was without it.

But I did not come to that conclusion after I convinced someone to lead me by the nose to it. In fact, I feel that if you are asking other people to convince you logic is worthwhile, you aren't ready for logic yet.

I see that "proof of God" has come up in the thread. God can't be proven or disproven. Logic has helped me form my own conclusion that there probably isn't a god or gods, and that my belief in it/them has allowed me to harm myself for many years. I chose to eliminate that harm. I choose to not believe in god(s) any longer. I choose to believe in nothing that I can't prove to myself, and if that proof is available, then it's no longer a belief, but a knowledge, a gnosis.

However, all of this is quite personal. Your mileage will most definitely vary. If you want to know about logic, study it. Form your own opinions, after an honest and sincere exploration--of this, or any other subject that interests you. But the spoon is broken. You can't be fed with it.

Why would you want to be?

RandFan

16th September 2007, 09:20 AM

Actually, some sceptics do say: "There is no god".I think Dawkins says it best. There is a possibility that there is a god. It is so unlikely though that we can say there is no god just as easily as we can say there is no teapot orbiting the sun (independent of earth that is).

But, you are correct, what they actually mean is something like: "At this time, we have found no evidence of god that doesn't have another, simpler, explanation. This could change when new evidence appears."No. That's not right. There is no evidence. Period. End of story. Full stop.

Beerina

16th September 2007, 04:23 PM

Actually, some sceptics do say: "There is no god".

Guilty!

But, you are correct, what they actually mean is something like: "At this time, we have found no evidence of god that doesn't have another, simpler, explanation. This could change when new evidence appears."

Yes, which often yields a pithy response along the line of, "At this time, we have found no evidence of unicorns, fairies, or of teapots in orbit around Betelgeuse that doesn't have another, simpler explanation. This could change when new evidence appears."

If this universe isn't what it seems to be, then I think it would be far more likely it's a virtual reality (so to speak, could be "real" in the sense that wood is really out there) created by advanced creatures for one of innumerable reasons.

BillyJoe

16th September 2007, 10:34 PM

I think Dawkins says it best. There is a possibility that there is a god. It is so unlikely though that we can say there is no god just as easily as we can say there is no teapot orbiting the sun (independent of earth that is).

No. That's not right. There is no evidence. Period. End of story. Full stop.

RandFan, I mostly agree with Dawkins.
I used the words "something like" and then quoted streamlet's post. So I wasn't meaning to go along with that post completely. I actually go with Dawkins when he says that it is highly unlikely that there is a god. I disagree, as you know, that god, in this respect, is the same as the tooth faerie (for a clearer example). And I disagree that it is okay to say "there is no god", when what you actually mean is that "it is highly unlikely that there is a god".
But, anyway, we have had that argument.

RandFan

17th September 2007, 12:59 AM

RandFan, I mostly agree with Dawkins.
I used the words "something like" and then quoted streamlet's post. So I wasn't meaning to go along with that post completely. I actually go with Dawkins when he says that it is highly unlikely that there is a god. I disagree, as you know, that god, in this respect, is the same as the tooth faerie (for a clearer example). And I disagree that it is okay to say "there is no god", when what you actually mean is that "it is highly unlikely that there is a god".
But, anyway, we have had that argument.Yes, I agree we have. We will simply disagree.

Thanks,

RandFan

blobru

17th September 2007, 06:33 AM

Actually, I am much less sophisticated than that.

If you cannot prove logic, then how can you be so sure of it that you disprove god with it?

Any sufficiently advanced system of logic will generate truths that can't be evaluated within the system; you need something (or someone) outside the system for that. So there are logics which can't prove themselves, but you can always invent a bigger logic that does prove the smaller one, and then an even bigger one, and so on... in theory until you get enough power to 'prove' or 'disprove' God (assuming everyone agrees with your axioms -- good luck with that!) :) However, the basic point is if God is meaningful, then whatever meaning you give It involves logic; if you want to talk about "God", you need logic; if not, then you're left with a meaningless God that you can never talk about, except to say It's "meaningless", "unknowable", "transcendent", or whatever?

Darth Rotor

17th September 2007, 05:21 PM

Can you prove the rules of logic somehow?

If there is no proof for logic, how can one be so sure in it?
Can you prove a hammer somehow?

Logic, and the rules of logic, are tools suitable for some tasks. A hammer is a tool suitable for some tasks. Math is a tool used in many fields of endeavor, and math uses the tool of logic for many of its most useful tools in the Great Big Tool Box of mental task accomplishment. (Igor Sikorsky used that, among other tools, to invent useful things like helicopters.)

Note: Complexity, thanks for the lovely summary about statements and other fundamental matters.

JetLeg:

What interest do you have in proving a hammer?

"If there is no proof for a hammer, how can one be so sure in it?"

Do you know how nonsensical that question is?

DR

JetLeg

18th September 2007, 03:33 AM

No, you can see a hammer, you cannot see logic.

JetLeg

18th September 2007, 04:05 AM

Any sufficiently advanced system of logic will generate truths that can't be evaluated within the system; you need something (or someone) outside the system for that. So there are logics which can't prove themselves, but you can always invent a bigger logic that does prove the smaller one, and then an even bigger one, and so on... in theory until you get enough power to 'prove' or 'disprove' God (assuming everyone agrees with your axioms -- good luck with that!) :) However, the basic point is if God is meaningful, then whatever meaning you give It involves logic; if you want to talk about "God", you need logic; if not, then you're left with a meaningless God that you can never talk about, except to say It's "meaningless", "unknowable", "transcendent", or whatever?

I am not that sure that if you are talking about meaning and definition, you are presupposing logic. Why?

cyborg

18th September 2007, 04:28 AM

No, you can see a hammer, you cannot see logic.

How do you think you see a hammer then? It simlpy 'happens'?

blobru

18th September 2007, 07:15 AM

I am not that sure that if you are talking about meaning and definition, you are presupposing logic. Why?

Logic is the study of statement and implication. Every definition is a statement: "Green is a color"; "Gravity is a force"; "God is great"; etc. So any statement, to have precise meaning, presupposes logic.

Aristotle's logic starts by defining "definition":
A is A (once you name some thing, then the name refers to that thing).
A is B or not-B (a thing either has a quality or it doesn't. If it does, that quality is part of its definition).
A is not B and not-B (sort of the same deal as above -- qualities themselves must be well-defined).

Seems a fair minimum for any "definition": so any proper definition is bound by logic, open to discussion and criticism.
Of course, there are plenty of non-logical statements that have "meaning" as well, but not precise meaning. Metaphorical statements can take on many meanings; for example -- "God is the first light of the evening star and the last light of the morning star"; "God is the bird's song in spring and the bird's flight in autumn"; "God is the hole in the donut and the swirl in the cocoa", etc. -- which may or may not "mean" any number of things to anyone; fun perhaps, suggestive, but certainly not well-defined. (Mind you this is how mystics talk about God; as long as you stick to metaphor, logic can't get you. But if you want your God to justify anything, like a system of ethics say, you need more than metaphor, which only offers images, not axioms).

Anyway, a bit long-winded, sorry! :) but that's why, I think.

Darth Rotor

18th September 2007, 09:34 AM

No, you can see a hammer, you cannot see logic.

But I can see reason, and I also know a fool when I see one.

DR

slingblade

18th September 2007, 01:22 PM

I can't see air. Air must not exist.

I can't see fear. It must not exist.

I can't see love, or time, or nothingness. Those things don't exist.

Above all, I can't see JetLeg (whatever the hell a jet leg is) so I know it doesn't exist.

JetLeg

18th September 2007, 02:01 PM

But it all ends up with logic being just a premise which you take. What if this premise is wrong?

cyborg

18th September 2007, 02:07 PM

What if this premise is wrong?

Logic cannot be 'wrong'. It merely has rules and consequences of those rules.

'Wrongness' requires something against which to decide the validity of a particular logic.

Mangafranga

18th September 2007, 02:12 PM

Logic cannot be 'wrong'. It merely has rules and consequences of those rules.

'Wrongness' requires something against which to decide the validity of a particular logic.So a logic which allows "If p then q, q, so p" is not wrong then?

cyborg

18th September 2007, 02:36 PM

So a logic which allows "If p then q, q, so p" is not wrong then?

Again, determining whether or not that logic is wrong is contingent on some qualification to compare it against.

Mangafranga

18th September 2007, 02:45 PM

Again, determining whether or not that logic is wrong is contingent on some qualification to compare it against.What is wrong with comparing it the world? This argument holds by that logic-

If I am writing the talk I will be giving in a few days then I am be typing on the keyboard
I am typing on the keyboard
So I am writing the talk I will be giving in a few days

The premises are true, the conclusion is false. Does this not indicate a deficient logic?

cyborg

18th September 2007, 02:50 PM

What is wrong with comparing it the world?

Did I say anything was 'wrong' about it? I just said you need something to compare a logic against in order to determine it's 'validity' - that is the validity of a logic is rather dependent on what you want it to do.

The premises are true, the conclusion is false. Does this not indicate a deficient logic?

If the validity of your logic requires that 'true' premises lead to 'true' conclusions then yes - but you should remember that 'true' and 'false' are just descriptors for an outcome of a logical process; do not equate them to 'right' and 'wrong'.

Mangafranga

18th September 2007, 03:24 PM

Did I say anything was 'wrong' about it? I just said you need something to compare a logic against in order to determine it's 'validity' - that is the validity of a logic is rather dependent on what you want it to do.

If the validity of your logic requires that 'true' premises lead to 'true' conclusions then yes - but you should remember that 'true' and 'false' are just descriptors for an outcome of a logical process; do not equate them to 'right' and 'wrong'.I didn't get the memo where we totally removed the semantics and the study of arguments from logic. So I will just state what I want from my logic.

I want my logic to formalize correct arguments. I would contend that the argument form I presented is just plain incorrect.

slingblade

19th September 2007, 07:40 AM

So a logic which allows "If p then q, q, so p" is not wrong then?

But logic doesn't "allow" that. This form is known as "affirming the consequent," and is an invalid form, a fallacy.

In words:
If it rains (p), then my car will be wet. (q)
My car is wet (q), therefore, it must have rained. (p)

One can immediately see the problem with this. There are other ways, besides rain, your car could get wet. Someone might have sprayed it with a hose, someone could have thrown a bucket of water, a street cleaner could have malfunctioned...other reasons.

But it's not that the logic is wrong; the logic shows you how the statement is invalid. Validity relates to form, soundness relates to content.

As was said before, by Darth, logic is but a tool one uses on words, statements, and arguments.

drkitten

19th September 2007, 07:53 AM

I didn't get the memo where we totally removed the semantics and the study of arguments from logic.

It might have been before your time; it was some time in the 1910s.

So I will just state what I want from my logic.

Cool. We serve all kinds in here.

I want my logic to formalize correct arguments.

Excellent. We have just what you want in stock -- I recommend first-order predicate calculus. It has exactly the property you need; it's "sound." It's also a nice, friendly, easy to use logic with wide application -- a good entry-level logic. I doubt you'll go very far wrong with that.

However, some of our (ahem) more specialized clientele have more, um, sophisticated needs into which "soundness" doesn't enter. A colleague of mine, for example, is interested in an automated hypothesis generator that will scan databases and propose hypothesis for investigation, and he's not as interested in "soundness" as he is in other aspects such as plausibility. Of course, he's also an expert user and is likely to tinker with the product himself as soon as he gets it home. Whatever. As I said, we serve all kinds here.

Mangafranga

19th September 2007, 08:54 AM

But logic doesn't "allow" that.Different people in this thread are using "logic" differently. Some people are using "logic" to just refer to the formalization of a syntax. Others are using it to refer to the study of inference.

I actually use it both ways. I have no problem with referring to a logic, meaning a formalization, and still holding that a logic can be correct or not in its ability to formalize correct inferences. Perhaps in this thread this isn't appropriate. I will now use "Logic" to mean the study of valid arguments. I will now use "logic" to mean a formalization.

But it's not that the logic is wrong; the logic shows you how the statement is invalid. Validity relates to form, soundness relates to content.No, the hypothetical logic I referred to actually claims that form is valid.

It might have been before your time; it was some time in the 1910s.You should send the memo out to all the philosophers of Logic, then. Perhaps you should also send the memo out to to the 1910 Russell. This would save him the effort of all the justification he wrote for the inferences in Principia.Excellent. We have just what you want in stock -- I recommend first-order predicate calculus. It has exactly the property you need; it's "sound." It's also a nice, friendly, easy to use logic with wide application -- a good entry-level logic. I doubt you'll go very far wrong with that.But there is that damn classical conditional, it just makes no sense. "If p, then q" is false only when the antecedent is true, and the consequent false. OK I buy that it is false in this case, but is this the whole story? What if the antecedent and consequent have no relevance to each other? And what about when the antecedent is false? Oh wait wait, sorry, I can't actually talk about that can I. "logic" can only mean a formalization, it can never make sense to talk about it's correctnesses. No-one ever talks about correct or incorrect inferences.However, some of our (ahem) more specialized clientele have more, um, sophisticated needs into which "soundness" doesn't enter. A colleague of mine, for example, is interested in an automated hypothesis generator that will scan databases and propose hypothesis for investigation, and he's not as interested in "soundness" as he is in other aspects such as plausibility. Of course, he's also an expert user and is likely to tinker with the product himself as soon as he gets it home. Whatever. As I said, we serve all kinds here.And a professor who is giving a talk this weekend, directly before I give my talk (ok ok I am just a student, but this is just as good as an appeal as yours) holds that there are multiple correct logics. He is a pluralist about Logic. Another Logician at the workshop holds that the concept of a second order logic doesn't make sense. I'll be sure to give them the bad news that they are both out of a job.

Finally I suggest that in the context of this thread, it is not unreasonable to think that "logic" should refer to the study of valid arguments. Further I contend that there is an objective measure of validity.

drkitten

19th September 2007, 09:19 AM

You should send the memo out to all the philosophers of Logic, then.

Most of the professionals already read it.

Perhaps you should also send the memo out to to the 1910 Russell.

I don't need to. He was one of the principel authors of the memo.

.But there is that damn classical conditional, it just makes no sense. "If p, then q" is false only when the antecedent is true, and the consequent false.

And that's part of the problem. That statement you make is, by 19th century standards, or late 20th century standards, silly. The idea that any conditional statement whose antecedent is false is true "just makes no sense" (and it's one of the hardest ideas to get across to first year students); it makes counterfactual reasoning and contingency planning impossible to formalize. FOPC's treatment of counterfactuals is considered to be one of its major weaknesses, and that's one reason that a lot of people prefer to use a different system in logical environments where "dirty" data is a real possibility.

The only reason that the FOPC formalism -- and it's not a "classical" formalism; it follows "classical" logic by something like two and a half millenia -- is used is because it's mathematically convenient and makes -> usefully different from = or <->. And it happens to be "correct" in the sense of "sound"; as long as we agree on what the if/then construction means, we will never be led into a contradiction. Now, if you want to propose a different interpretation for that symbol, you're welcome to. But assigning meanings to symbols is not a property of the logic, but a property of the interpretation. (See the Lowenheim-Skolem theorem for examples of that.)

Oh wait wait, sorry, I can't actually talk about that can I. "logic" can only mean a formalization, it can never make sense to talk about it's correctnesses.

Well, yoiu obviously can't talk about that. Professional logicians can and do talk about correctness, but they recognize is as a property that does not reside solely in the "logic."

No-one ever talks about correct or incorrect inferences.

Bullfrog. Logicians talk about that all the time. But the correctness of a particular logic can only be established against particular models, which is

And a professor who is giving a talk this weekend, directly before I give my talk (ok ok I am just a student, but this is just as good as an appeal as yours) holds that there are multiple correct logics.

He's right, although he probably used more correct terminology than you did.

Another Logician at the workshop holds that the concept of a second order logic doesn't make sense.

He, on the other hand, sounds like a quack. Or more likely, you didn't understand him.

Finally I suggest that in the context of this thread, it is not unreasonable to think that "logic" should refer to the study of valid arguments.

Suggest away. We are under no compulsion to pay attention to your suggestions borne of ignorance.

Further I contend that there is an objective measure of validity.

Contend away. You're still wrong.

Mangafranga

19th September 2007, 10:05 AM

I am going to just sum up my position. If we understand "logic" as a just a way to manipulate symbols (i.e. all we can talk about is a particular logic), then there is no answer to the OP, and indeed the question doesn't even make sense. If we understand "logic" as being the study of valid (correct, good, truth preserving or whatever you prefer) arguments, there is an answer. We can give an account of what makes a valid argument (and there are multiple answers to this). So we can tell a story about truth preservation. We can say that a valid argument is one in which it can't be such that the premises are true, and the conclusion false. We can concede that the methodology is similar to science, in that it is hard to confirm a theory, but it can be falsified. We can at least know that some arguments are invalid (e.g. the fallacy I mentioned, or a more interesting case is the failure of "(p and (q or r)) <-> ((p and q) or (p and r))" in quantum mechanics).

JetLeg

19th September 2007, 10:37 AM

You said : If we understand "logic" as being the study of valid (correct, good, truth preserving or whatever you prefer) arguments, there is an answer. We can give an account of what makes a valid argument (and there are multiple answers to this).

If we understand this as logic, what answer can there be?

In order to prove that some arguments are valid and some are not, you need to pressupose a way of proving that. But that would be presupposing what you need to prove.

You need to assume an epistemology to prove one, and you can't do it -> so there is no way to prefer one epistemology to another.

Mangafranga

19th September 2007, 10:56 AM

In order to prove that some arguments are valid and some are not, you need to pressupose a way of proving that. But that would be presupposing what you need to prove.You said before that you can see a hammer, but you can't see logic. Well, compare the inferences to the world. Has it ever been that, for instance, the premises of the argument "p or q, ~p, so q" have been true, while the conclusion has been false. The system of proof here is simply looking at the world to see if there has been a case where this argument hasn't held. If not, we accept the argument as valid (and just like in science we accept that it may be falsified in the future, but so what).

RandFan

19th September 2007, 11:22 AM

But it all ends up with logic being just a premise which you take. What if this premise is wrong?Nonsensical but I get the gist of what you are asking. I'm capable of abstract thought. I've read Carroll many times and sometime in my twenties I actually got it. Hint: the adventures of Alice in Wonderland and Through The Looking Glass are not simply children's stores.

Ok, I'll bite, what if the premise is wrong? Can you live your life in any other way than that which is logical?

Now for the fun. If the premise is wrong and we assume your premise, how can we consider and answer your question?

Wait, I've got it!

The answer is @x!$^vstoeo.

Did that answer your question? Did you find it sufficiently illogical?

Jet, you can toss out logic if you want but I'm affraid you will have to sit in a corner and drool or somethin akin to that. When you come here and EMPLOY LOGIC in an attempt to question logic I can only want to smak you in the head.

drkitten

19th September 2007, 11:46 AM

I am going to just sum up my position. If we understand "logic" as a just a way to manipulate symbols (i.e. all we can talk about is a particular logic), then there is no answer to the OP, and indeed the question doesn't even make sense.

I'm glad you've summed it up, because it makes it much easier to show that you are wrong.

If we treat logic as a way of manipulating symbols, then there are several ways that we can "prove" logic to be correct (depending upon how you define correct), and most of them were explored during the first half of the twentieth century.

It is, for example, possible to prove that manipulating symbols according to the rules of FOPC cannot produce a statement of the form (P ^ ~P). Since the conventional interpretation of this statement is "P and not-P," a contradiction, this means that following the rules of FOPC will not introduce contradictions into an otherwise sensible model of the universe. (This was Goedel's Completeness Theorem).

It's also possible to prove that in any model M in which P is derivable using FOPC, P is also a consequence. (that is, if M|-P, M|=P). That's also the "soundness" property defined purely in terms of symbol manipulation.

For example, we may have an unsound logic that is nevertheless sound over some models but not all, and as long as we choose our model appropriately, the logic "works."

If we understand "logic" as being the study of valid (correct, good, truth preserving or whatever you prefer) arguments

... then we understand logic incorrectly. This understanding was abandoned nearly a hundred years ago.

We can give an account of what makes a valid argument

Yes, but we can do that in the standard formalism as well, and we can go well beyond and discuss under what models a given argument is or is not valid. Because validity is not just a property of the argument, but of the world model to which it applies.

cyborg

19th September 2007, 12:35 PM

Well Dr K has covered it quite well but the basic point remains:

Semantics comes after syntax.

Mangafranga

19th September 2007, 01:26 PM

So would someone like to explain what the arguments over K, S4, S5 are about? And would someone like to explain what Putnam was doing when he argued that logic is an empirical science?

drkitten

19th September 2007, 01:53 PM

So would someone like to explain what the arguments over K, S4, S5 are about?

In a nutshell, they're about whether the formal syntax of the logic is appropriate to represent the domains in the real world about which we wish to reason.

For example : K is a very simple form of "modal" logic (and a very weak one). By "modal" logic, I mean a logic that purports to capture the distinctions between necessity and contingency; it is necessary that a full coffee cup is full, because that's what the phrase "a full coffee cup" means. It is merely contingent that my coffee cup is full right now; sometimes it's full, sometimes it's empty, it just depends on when you catch me.
(Also note that it's not just a question of form. It is not, for example, necessary that a small elephant be small, because something that is small for an elephant is still pretty darn big. Philosophers have gotten their panties tied in knots for centuries over this one.)

And, in fact, K, although a provably "sound" logic and provably "complete" in some sense doesn't really capture what most people think "necessary" means. That's why people argue about which logic to use. In the words of a web page I will cite in a bit, "Consider the English version of LMLp: It is necessarily possible that it is necessary that p. It is unclear what, if anything, that statement means." If you don't have a clear intuition about what that means, it's hard to say that any meaning assigned to it is definitively wrong. "One reason S5 is the most popular logic is that all statements with nested modalities (such as LMLp) reduce to statements with a single modal operator. [...] In S5, you can simply delete all the modal operators except the last one. This means that LMLp is equivalent to Lp. Lp has an easy (and meaningful) translation. In S4.2, all strings of modal operators are equivalent to one of the following strings: L, M, ML, LM."

Now, I would argue that S5 does not capture the nuances of the real world; there's a difference between something that is necessary, something that is possible, and something that is possibly necessary. So I prefer S4.2 as a better model of the unbounded world than S5. But there are also a lot of restricted environments where S5 better captures what's going on.

The site goes on to say : "In fact, I see the lack of meaning to be the great strength of logic and math. The reason mathematic representations of the world and formal logical representations of thought have been so effective is that we are free to reinterpret the semantic content of the relevant symbols as appropriate for a given context." I find it hard to improve on that phrasing.

Logic is a tool. If you only know one logic, you only have one tool.

The site, by the way, is http://dtww.blogspot.com/2005/03/logic-is-for-tricking-people.html

Mangafranga

19th September 2007, 01:59 PM

From Logic and Ontology, SEP (http://plato.stanford.edu/entries/logic-ontology/)

There are several quite different topics put under the heading of ‘logic’ in contemporary philosophy, and it is controversial how they relate to each other. 2.1. Different conceptions of logic

On the one hand, logic is the study of certain mathematical properties of artificial, formal languages.Seems to be how you are using it. Let me see, my conception covered?
A second discipline, also called ‘logic’, deals with certain valid inferences and good reasoning based on them.Yep, so this makes the first part of your statement... then we understand logic incorrectly.seem rather dubious. Perhaps your second part
This understanding was abandoned nearly a hundred years ago.is supported
A second discipline, also called ‘logic’, deals with certain valid inferences and good reasoning based on them.
...snip to the end of this paragraph...
The central notion of logic in this sense is the notion of logical consequence. How this notion should be understood more precisely is presently widely debated, and a survey of these debates can be found in the entry on logical consequence (http://plato.stanford.edu/entries/logical-consequence/).And perusing the bibliography of this entry finds plenty of recent work. So this statement of yours seems incorrect.

Loss Leader

19th September 2007, 02:03 PM

But it all ends up with logic being just a premise which you take. What if this premise is wrong?

"Your system could be wrong therefore all systems of belief are equal and my wackdoodle beliefs are just as valid as yours."

Yiab

19th September 2007, 02:45 PM

Semantics comes after syntax.

In the idealized realm of abstraction known as mathematical logic (equally, philosophical logic), yes. In reality, of course, the human species developed syntax and semantics together and only learned fairly recently that they are seperable.

Actually, if we look at the way logical languages are chosen for study, we often start with a particular semantics in mind and develop a syntax we hope will reflect it. We then explore what the limits of expression are within that syntax.

For example, Euclid developed geometry with some very specific semantic choices in mind for his terminology ("point" and "line" meaning, well, point and line respectively), but he also realized that these semantic choices are independant of what he was proving. Later, we found that if we took the axioms of projective geometry and decided "point" would refer to a line and "line" would refer to a point, it would still make sense.

In this sense, syntax is developed after semantics but is independant thereof.

JetLeg

19th September 2007, 02:52 PM

Do you all agree on the way of prooving logic, as Magafranga said ? :

You said before that you can see a hammer, but you can't see logic. Well, compare the inferences to the world. Has it ever been that, for instance, the premises of the argument "p or q, ~p, so q" have been true, while the conclusion has been false. The system of proof here is simply looking at the world to see if there has been a case where this argument hasn't held. If not, we accept the argument as valid (and just like in science we accept that it may be falsified in the future, but so what).

JetLeg

19th September 2007, 02:53 PM

You said before that you can see a hammer, but you can't see logic. Well, compare the inferences to the world. Has it ever been that, for instance, the premises of the argument "p or q, ~p, so q" have been true, while the conclusion has been false. The system of proof here is simply looking at the world to see if there has been a case where this argument hasn't held. If not, we accept the argument as valid (and just like in science we accept that it may be falsified in the future, but so what).

And how do you proove that a specific fallacy in logic is a fallacy?

For example, ad hominem - how do you prove that is a fallacy?

slingblade

19th September 2007, 02:58 PM

And how do you proove that a specific fallacy in logic is a fallacy?

For example, ad hominem - how do you prove that is a fallacy?

That's easy. Let's assume I smoke. Smoking is bad for one's health. This statement is true regardless of who utters it. Therefore, it is fallacious to say that my premise has no merit because I smoke. It has merit, regardless of the speaker's habits.

That's how you prove (one O) an ad hom.

Robin

19th September 2007, 04:58 PM

And how do you proove that a specific fallacy in logic is a fallacy?

For example, ad hominem - how do you prove that is a fallacy?
If you are talking about proof, then you must be talking about formal logic, there is no concept of ad hominem in formal logic.

In fact you could put phrase ad hom so that it would be formally valid, so "atheists are evil, Richard Dawkins is an atheist, therefore Richard Dawkins is evil" would be formally valid.

Robin

19th September 2007, 05:03 PM

As for the question in the OP, yes you can prove the rules of logic. Pick up a good text book on Discrete Mathematics and you will find that all the rules of logic for any given system require and have proofs.

But you can't prove the axioms. They are, well, axiomatic.

RandFan

19th September 2007, 08:11 PM

And how do you proove that a specific fallacy in logic is a fallacy?

For example, ad hominem - how do you prove that is a fallacy?Do you accept mathmatical proof?

If I say that I have two apples and I give you one and that leaves one would you accept that 2-1=1?

cyborg

20th September 2007, 02:54 AM

For example, ad hominem - how do you prove that is a fallacy?

Well, if the ad hominem was a valid argument in this reality then by merely calling you an idiot then I could prove that you will agree with me in the next sentence. You would be unable to avoid this consequence.

So - does attacking people change reality?

If yes answer: "ad hominem is a valid argument."

If no answer: "ad hominem is not a valid argument."

And add this to your set of fallacies.

JetLeg

20th September 2007, 04:01 AM

OK. How do you evelauate this argument for example :

An indian wiseman has a certain doctrine. His doctrine is that that our Atman is actually are a part of the cosmic Brahman. Also, he predicts that when one should meditate on this truth, he will become extraordinarily happy. He does it. Other people meditate on this doctrine. The results are as he predicted, certified by brain scans. Does it proof that our Atman is actually a part of the cosmic Brahman?

cyborg

20th September 2007, 04:17 AM

Does it proof that our Atman is actually a part of the cosmic Brahman?

Without existential referrents that is just a meaningless jumble of symbols comprised from the Latin alphabet.

JetLeg

20th September 2007, 04:20 AM

No, you will have to go to the indian wise man and ask him what he means by it...

JetLeg

20th September 2007, 04:23 AM

Do you accept mathmatical proof?

If I say that I have two apples and I give you one and that leaves one would you accept that 2-1=1?

Yes, why not?

cyborg

20th September 2007, 04:24 AM

No, you will have to go to the indian wise man and ask him what he means by it...

So I can get another set of meaningless symbols in another arbitrary language relating to the mental processes of another man whose symbols may or may not relate to meaningful existential referrents?

At some ponit JetLeg somebody is actually gonig to have to point at an actually 'thing' before the 'word' means anything at all. Otherwise you are not much better than Eliza which has no concept of what English means to a human because it has no concept of what the external world we live in is like.

cyborg

20th September 2007, 04:25 AM

Yes, why not?

I say 2-1 = 3.

Am I wrong?

JetLeg

20th September 2007, 04:27 AM

So I can get another set of meaningless symbols in another arbitrary language relating to the mental processes of another man whose symbols may or may not relate to meaningful existential referrents?

At some ponit JetLeg somebody is actually gonig to have to point at an actually 'thing' before the 'word' means anything at all. Otherwise you are not much better than Eliza which has no concept of what English means to a human because it has no concept of what the external world we live in is like.

Would you agree at least that you have proven the symbols "Atman is Brahman" to be true, whatever they mean?

JetLeg

20th September 2007, 04:53 AM

I say 2-1 = 3.

Am I wrong?

Yes, you are. Proof via apples. But does it relate to the indian man?

A proof via apples : I take two apples, and then eat one. Count the number. Result is not 3.

cyborg

20th September 2007, 05:30 AM

Yes, you are.

I am?

Proof via apples.

Proof via apples? I don't see what apples have got to do with anything.

But does it relate to the indian man?

Not in my universe. But then you just went ahead and assumed you knew which one I was talking about didn't you?

cyborg

20th September 2007, 05:34 AM

Would you agree at least that you have proven the symbols "Atman is Brahman" to be true, whatever they mean?

Not unless you want to agree that until it's liked to it those labels have got nothing to do with our reality. In which case I'll be happy to entertain it is 'true' - as meaningless as that is.

JetLeg

20th September 2007, 05:39 AM

Not unless you want to agree that until it's liked to it those labels have got nothing to do with our reality. In which case I'll be happy to entertain it is 'true' - as meaningless as that is.

Apples - edited in post above.

Indian man - sorry, I don't understand you.
What other hipothesis can you bring for the happiness of this man, other than his own?

cyborg

20th September 2007, 06:06 AM

Apples - edited in post above.

In my universe when 'I have two apples' and 'I eat one', 'I get three' is 'true'.

What other hipothesis can you bring for the happiness of this man, other than his own?

Well JetLeg, if you accept that words in and of themselves have no meaning whatsoever but are merely placeholders - currency - for experiences then you have a start.

Next if you realise that post hoc ergo propter hoc (after this, therefore because of this) is a fallacy you can begin to see why simply constructing any explanation before hand and then saying it explains what happened afterwards is liable to be wrong.

(Which you don't do otherwise you would accept my explanation of Dancing Rainbows Enchantedly Ambling Meaningfully (DREAM for short) as an explanation for why you are able to reply to my post).

I could come up with an infinite number of hypotheses JetLeg since there are any number of things I could have said before hand - oh and what's this? Why, it appears that similar phenomena occur in other cultural idioms with different names and stories but with the same human psychological effect.

Well I guess I could go the post hoc ergo propter hoc route and simply accept that any 'explanation' given before hand constitutes a meaningful communication or I could try to formulate a consistent logic that applies to everyone regardless of the labels they choose to use.

Which one do you think I should do and why?

JetLeg

20th September 2007, 06:26 AM

In my universe when 'I have two apples' and 'I eat one', 'I get three' is 'true'.

Well JetLeg, if you accept that words in and of themselves have no meaning whatsoever but are merely placeholders - currency - for experiences then you have a start.

Next if you realise that post hoc ergo propter hoc (after this, therefore because of this) is a fallacy you can begin to see why simply constructing any explanation before hand and then saying it explains what happened afterwards is liable to be wrong.

(Which you don't do otherwise you would accept my explanation of Dancing Rainbows Enchantedly Ambling Meaningfully (DREAM for short) as an explanation for why you are able to reply to my post).

I could come up with an infinite number of hypotheses JetLeg since there are any number of things I could have said before hand - oh and what's this? Why, it appears that similar phenomena occur in other cultural idioms with different names and stories but with the same human psychological effect.

Well I guess I could go the post hoc ergo propter hoc route and simply accept that any 'explanation' given before hand constitutes a meaningful communication or I could try to formulate a consistent logic that applies to everyone regardless of the labels they choose to use.

Which one do you think I should do and why?

Where does the indian man explanation has a post-hoc-ergo-proper-hoc fallacy? He stated beforehand, that due to realizing atman is brahman happiness is achieved, not after the meditation.

cyborg

20th September 2007, 06:34 AM

Where does the indian man explanation has a post-hoc-ergo-proper-hoc fallacy?

*Sigh*

He stated beforehand, that due to realizing atman is brahman happiness is achieved, not after the meditation.

That would kinda be the point. He stated ANY (literally ANY - do I need to explain this concept more fully?) explanation beforehand and then it was ACCEPTED afterwards merely by virtue of what he said was to occur afterwards occurring not because of a causal chain of deduction starting with the entities he named all the way to the effects they caused.

No, we just accept the etities he named exist based on the aftermath of some phenomena and that the preceeding statement had real meaning.

Work with me here, just go wild with your imagination.

If he had said in some other universe:

"If you synergise time management with cash flows then profit is achieved."

Would this explanation be better, worse, wrong, right, meaingful, meaningless: what? And more importantly WHY?

JetLeg

20th September 2007, 08:05 AM

You mean that saying "we need to realize atman is brahman", is just the same as saying "we need to realize that boogie is shmoogie"?

cyborg

20th September 2007, 08:13 AM

Yep.

JetLeg

20th September 2007, 08:14 AM

Ok, don't you agree that this indian wise man could prove that "boogie is shmoogie" in such a way?

cyborg

20th September 2007, 08:16 AM

I can only refer back to my earlier statement:

Not unless you want to agree that until it's liked [sic - should be likened] to it those labels have got nothing to do with our reality. In which case I'll be happy to entertain it is 'true' - as meaningless as that is.

You can prove anything using logic as they say. That's why it's important to choose the right one.

JetLeg

20th September 2007, 08:22 AM

Ok, so why is this the choice of the wrong logic? It is a proof that "boogie is shmookie", whatever it means. We just have to ask the indian man for the meaning of the symbols.

cyborg

20th September 2007, 08:30 AM

Ok, so why is this the choice of the wrong logic?

Well it's wrong if you want to formulate good explanations about the observable phenomena that occur around us.

We just have to ask the indian man for the meaning of the symbols.

And in what form will he give us that meaning?

If he just gives a whole bunch more of symbols are we any closer to getting any actual meaning? Or is it just sufficient that we go around saynig, "have you realised the boogie in the shmoogie yet?" with others nodding along for fear of looking stupid if they don't have a clue what it means and then passing on the meaningless nonsense to others to appear wise, "I've boogied my shmookie! Have you?"

You do that often enough and you drain language of any capacity to communicate meaningful ideas at all.

drkitten

20th September 2007, 08:37 AM

Ok, so why is this the choice of the wrong logic? It is a proof that "boogie is shmookie", whatever it means. We just have to ask the indian man for the meaning of the symbols.

Ah, yes, the "you can't get out of the dictionary problem."

Asking the guru for the meanings won't work because that will simply give you more undefined words. Think of it this way. If I give you a Martian dictionary -- not a Martian to English dictionary, but the Martian equivalent of Websters or the OED, but without pictures -- could you learn the Martian language from it? After all, every word in the dictionary comes with a definition. So if you're not sure what xozblat means, you can just look it up. But at no point will it connect with any words or concepts that are meaningful to you.

JetLeg

20th September 2007, 08:46 AM

Yiab

20th September 2007, 08:50 AM

Where does the indian man explanation has a post-hoc-ergo-proper-hoc fallacy? He stated beforehand, that due to realizing atman is brahman happiness is achieved, not after the meditation.

If I say "my toes are actually gigantic yellow tyrannosaurs engaged in a battle to the death, therefore meditation on this will lead to happiness" then proceed to meditate and become happy, would you agree that I have proven that my toes are actually gigantic yellow tyrannosaurs engaged in a battle to the death?

This is precisely post hoc ergo propter hoc, let me make it more formal.
A = "atman is brahman"
B = "you meditate on this truth"
C = "you become happy"
The hypothetical indian man in your example said:
$A \rightarrow (B \rightarrow C)$
There are actually two instances of the post hoc fallacy here. First, he became happy after meditating, therefore he assumed that the happiness was because of the meditation, that is he decided:
$C$, $B\rightarrow C$ therefore $B$
Further, he then said that since his conclusion was correct, his assumption must also be correct, so he said:
$B\rightarrow C$, $A\rightarrow(B\rightarrow C)$ therefore $A$

Formally, he used the logical fallacy "affirming the consequent" twice, in non-formal contexts this is usually referred to as "post hoc ergo propter hoc".

cyborg

20th September 2007, 08:52 AM

Well, maybe you will have to the guru's ashram for years to learn the meaning of the words.

And maybe it's all just the equivalent of ancient marketing speak - big full and impressive sounding words underpinned by... more big full and impressive sounding words where you are made to feel stupid if you don't understand them.

Synergise that if you can.

do you agree that it is a way to prove "boogie is shmookie",

JetLeg you are clearly not getting this: you can prove anything. It is really rather trivial to construct a logic where that string of symbols would be 'proven'.

and the second is how we understand it AFTER it has been proven.

Ah yes - what's that called again?

post hoc ergo propter hoc

You've got to start from first principles, not start from the conclusions and then try to build a system to fit them.

drkitten

20th September 2007, 08:52 AM

Well, maybe you will have to the guru's ashram for years to learn the meaning of the words.

There are two different issues - do you agree that it is a way to prove "boogie is shmookie", and the second is how we understand it AFTER it has been proven.

No, the two issues are related. One of the main reasons it's not an acceptable proof is because it's not meaningful, regardless of whether it's logically sound.

JetLeg

20th September 2007, 09:13 AM

A = "atman is brahman"
B = "you meditate on this truth"
C = "you become happy"
The hypothetical indian man in your example said:
$A \rightarrow (B \rightarrow C)$
There are actually two instances of the post hoc fallacy here. First, he became happy after meditating, therefore he assumed that the happiness was because of the meditation, that is he decided:
$C$, $B\rightarrow C$ therefore $B$

Listen, you CAN know sometimes that if you eat yoghurt, you have a stomach ache. Right? Or, that if you go to forests, you feel happy. You cannot know that from a single occasion of eating, or going to the forests, but you have enough experience with yourself to rule other factors after several "expiriments".

Agreed so far?

So, the indian can 'run' a control group on himself - not meditating, meditating on different things, eating mushrooms - so he can know what exactly causes the meditation.

The only thing we have to assume is that he is not lying.

Thanks for the explanation.

cyborg

20th September 2007, 09:32 AM

JetLeg

20th September 2007, 09:37 AM

*Sigh* You are not getting it.

Effect follows cause, but that does not mean what you *think* caused the effect actually caused it. That is what the fallacy is all about - co-incidental occurrences and invalid backward chaining.

So is it the yoghurt per se that caused the ache? Is it the forest per se that caused the happiness? What is the actual explanation for these feelings?

No. He is biased. It is irrelevant whether or not he is 'lying' - he is biased to interpret the symbols he sees as causative as causative because of the (flawed) hypothesis created.

This is the whole damn problem - you mind literally cannot tell the difference between symbols that are meaningful and those that are not. Therefore you MUST be blind to them in order to prevent your brain creating incorrect assumptions.

I agree that you can't deduce cause from effect, just because it follows. But, what you need to do, is run a few "tests". For example

I eat yoghurt and my stomach hurts.

Did it hurt before?
Is there anything else I ate?

Ok, lets try again on another day. Does it happen again?

Now lets try it in another room. Does it happen again.

THEN you can conclude it without a fallacy. Otherwise you are saying that it is impossible to understand cause-effect relationship.

cyborg

20th September 2007, 09:45 AM

But, what you need to do, is run a few "tests".

Good. You agree empiricism is a sensible way of doing things.

I eat yoghurt and my stomach hurts.

Did it hurt before?
Is there anything else I ate?

Ok, lets try again on another day. Does it happen again?

Now lets try it in another room. Does it happen again.

Your protocol lacks rigor to say the least.

THEN you can conclude it without a fallacy.

Can you? What is there is some other underlying medicial condition which is merely exacerbated by eating? You provided no control therefore concluding the yoghurt is a causal agent is premature.

Just like concluding the "atman in the bratman" or whatever is the reason for people getting happy when meditating on it. There is no control and there cannot be without blinding - trying to self-control does not work. No one can do it. NO ONE.

JetLeg

20th September 2007, 09:47 AM

Good. You agree empiricism is a sensible way of doing things.

Your protocol lacks rigor to say the least.

Can you? What is there is some other underlying medicial condition which is merely exacerbated by eating? You provided no control therefore concluding the yoghurt is a causal agent is premature.

Just like concluding the "atman in the bratman" or whatever is the reason for people getting happy when meditating on it. There is no control and there cannot be without blinding - trying to self-control does not work. No one can do it. NO ONE.

Please tell me what confounding factors might cause the happiness. I think it is very reasonable for someone to find out that meditation causes him hapiness?

JetLeg

20th September 2007, 09:49 AM

drkitten

20th September 2007, 09:52 AM

But, what you need to do, is run a few "tests". For example

I eat yoghurt and my stomach hurts.

Did it hurt before?
Is there anything else I ate?

Ok, lets try again on another day. Does it happen again?

Now lets try it in another room. Does it happen again.

THEN you can conclude it without a fallacy. Otherwise you are saying that it is impossible to understand cause-effect relationship.

Yes, that's exactly what cyborg is saying -- and that's one of the reasons that "logic" can be so tricky. Because it is impossible to understand cause-effect relationships, which is one reason that scientists sometimes get stuff wrong.

As a simple example -- you probably didn't know that I replaced your steel spoon with one made from a tricky metallic arsenic mixture. You're getting sick every time you eat yoghurt, not from the yoghurt, but from the spoon you use to eat yoghurt with. The yoghurt didn't cause the ache. There are always alternative hypotheses that need to be considered, and "running a few tests" will never give you enough information to exclude all of them.

Yes, this means that the scientitic method is one big exercise in post hoc ergo propter hoc and fundamentally fallacious. Science is unsound; it's possible to exercise the scientific method properly and still come to a wrong conclusion. That's one reason that scientists don't take formal logic that seriously; it's an inappropriately strict standard, because getting something right 99.9% of the time is good enough for most scientists. Any line of reasoning that can possibly go wrong is technically fallacious, even if it's right sometimes (or even most of the time).

In an earlier post I wrote:

Excellent. We have just what you want in stock -- I recommend first-order predicate calculus. It has exactly the property you need; it's "sound." It's also a nice, friendly, easy to use logic with wide application -- a good entry-level logic. I doubt you'll go very far wrong with that.

However, some of our (ahem) more specialized clientele have more, um, sophisticated needs into which "soundness" doesn't enter. A colleague of mine, for example, is interested in an automated hypothesis generator that will scan databases and propose hypothesis for investigation, and he's not as interested in "soundness" as he is in other aspects such as plausibility.

My colleague is, as you might expecte, a scientist. He's not as interested in not-going-wrong as going-in-an-interesting-direction. Of course, "right" is interesting -- but so is some stuff that's "wrong" but we don't know it yet.

Mashuna

20th September 2007, 09:54 AM

Please tell me what confounding factors might cause the happiness. I think it is very reasonable for someone to find out that meditation causes him hapiness?

JetLeg, I'm very confused by your notion of logic in two of the threads you've started. In one thread (Is It), you're arguing that because one can't disprove the existance of an immaterial, non-consequential god, it's as likely to be true as not. Your standard there for disproving something is ridiculously high.

In this thread, you seem to be happy to accept a causal link between someone claiming meditation causes happiness, therefore Atman is Brahman. Your standard for proving something is ridiculously low (as well as logically flawed).

drkitten

20th September 2007, 09:57 AM

Please tell me what confounding factors might cause the happiness.

Mild arthritis. Not moving = not irritating the joints = not being in low-level pain = happiness.

One simple example.

Ear troubles. Being in a quiet room = not irritating his ears through sound = not being in low-level pain = happiness.

Another simple example.

Stretching. Assuming a meditative posture = releasing endorphins due to muscle activity = happiness.

A third simple example.

Need more? I could come up with these all day; identifying potential confounds and alternate causes is a professional skill for anyone who really does empirical studies.

JetLeg

20th September 2007, 10:05 AM

Mild arthritis. Not moving = not irritating the joints = not being in low-level pain = happiness.

One simple example.

Ear troubles. Being in a quiet room = not irritating his ears through sound = not being in low-level pain = happiness.

Another simple example.

Stretching. Assuming a meditative posture = releasing endorphins due to muscle activity = happiness.

A third simple example.

Need more? I could come up with these all day; identifying potential confounds and alternate causes is a professional skill for anyone who really does empirical studies.

Please do more. I assume

-1- that the meditators are genuinely interested in finding out whether meditation causes them the mental states, or something else
-2- are intellectualy honest
-3- meditate quite a lot, so they can weed out confounding factors

The examples you gave are very good for one-time positive meditation experience, but not for long-life intellectually sincere intelligenent meditators. (I am talking about tibetan buddhists - you can google "Mind and Life institute")

cyborg

20th September 2007, 10:06 AM

JetLeg

20th September 2007, 10:07 AM

JetLeg, I'm very confused by your notion of logic in two of the threads you've started. In one thread (Is It), you're arguing that because one can't disprove the existance of an immaterial, non-consequential god, it's as likely to be true as not. Your standard there for disproving something is ridiculously high.

In this thread, you seem to be happy to accept a causal link between someone claiming meditation causes happiness, therefore Atman is Brahman. Your standard for proving something is ridiculously low (as well as logically flawed).

To be completely honest - it seems to me that it is related to the fact, that I would love something not to be disproved in IS IT thread, and would love something to be proved in this thread.

But, nevertheless, my arguments seem to make sense to me in both of the threads, so I will not do an ad-hominem to myself.

drkitten

20th September 2007, 11:00 AM

Please do more. I assume

-1- that the meditators are genuinely interested in finding out whether meditation causes them the mental states, or something else
-2- are intellectualy honest
-3- meditate quite a lot, so they can weed out confounding factors

Unfortunately, the second half of your third assumption is simply wrong. No finite amount of experimentation can weed out the infinite number of possible alternative hypotheses. (This particular observation goes all the way back to the logical positivists and before, but it was framed in its most strident form by Popper and Quine.)

That's why "replication" is a key factor in empirical science, but not in "logic"; it would be a very good idea for me (as a bench scientist) to replicate some of the classic findings in my field of study as part of my research program. On the other hand, I have no need to re-prove the classic logical findings, because logical findings are typically "sound" in the sense defined above; there's no possibility that Godel got his Completeness Theorem wrong, but there's a very definite possibility that Milliken got the mass of the electron wrong.

Yiab

20th September 2007, 12:27 PM

Listen, you CAN know sometimes that if you eat yoghurt, you have a stomach ache. Right? Or, that if you go to forests, you feel happy. You cannot know that from a single occasion of eating, or going to the forests, but you have enough experience with yourself to rule other factors after several "expiriments".

Agreed so far?

No. No matter how many times the second event follows the first you cannot strictly logically conclude that the implication is valid. Within real life you can reasonably assume that the implication holds, in fact you can hold that assumption strongly enough that the alternative never really crosses your mind, but that does not prove anything about the logical status of the implication.

So, the indian can 'run' a control group on himself - not meditating, meditating on different things, eating mushrooms - so he can know what exactly causes the meditation.

The only thing we have to assume is that he is not lying.

Thanks for the explanation.

A "control" group would have to consist of many people from many different backgrounds at many different stages of life with different neurochemical balances and, preferably, with different assumptions about the nature of reality going into the experiment. It would then need some verifiable and repeatable method of inducing a meditative state and of measuring an individual's happiness. All of these things could (in principal) be done in reality, but none of this affects the strictly logical status of the implication in question.

Additionally, even if every single one of the people, after having meditation reliably induced, attained a measurably high level of happiness in a reasonable and pre-defined length of time thereafter, you could only scientifically conclude that meditation in that specific manner probably induces happiness. Even if meditation induces happiness that says nothing about whether or not "atman is brahmin" - just because that was the reason to try meditating doesn't mean it is even supported by the hypothetical result.

I agree that you can't deduce cause from effect, just because it follows. But, what you need to do, is run a few "tests". For example

I eat yoghurt and my stomach hurts.

Did it hurt before?
Is there anything else I ate?

Ok, lets try again on another day. Does it happen again?

Now lets try it in another room. Does it happen again.

THEN you can conclude it without a fallacy. Otherwise you are saying that it is impossible to understand cause-effect relationship.

Were you sitting down every time you ate yoghurt? If so, sit down to read a book - does your stomach hurt again?
Were you always eating the same flavour of yoghurt?
Were you always eating the same brand of yoghurt?
Were you always eating yoghurt on an empty stomach?
Were you always in the same emotional state when eating yoghurt?
Were you always eating yoghurt at the same time of day?
Were you always eating yoghurt at the same altitude above sea level?
Were you always eating yoghurt in the same manner (i.e. slowly, one spoonful at a time or were you freezing it and swallowing it in a single chunk)?
Were you always standing up in the same way after eating the yoghurt?
Are you an idiot (i.e. did you punch yourself in the stomach soon after each time you ate yoghurt)?
How long was the yoghurt sitting in the fridge before you ate it?
Was the yoghurt sitting in the fridge before you ate it?
Eat an apple - does your stomach hurt?
Drink some milk - does your stomach hurt?
Eat some chicken - does your stomach hurt?
Filter the yoghurt for 3-inch long iron screws - did you find any?
Try yoghurt packaged in a different substance - does your stomach hurt again?
Get a friend to randomly line up 100 containers, 50 of which contain yoghurt and 50 of which contain an inert substance which is indistinguishable from yoghurt through sight, sound, touch, taste or smell - can you reliably tell which ones are yoghurt based on whether or not your stomach hurts?

After all that, I would say you can scientifically conclude that yoghurt makes your stomach hurt with very high likelihood. However, that does not prove anything about the logical status of the implication.

JetLeg

20th September 2007, 04:21 PM

Unfortunately, the second half of your third assumption is simply wrong. No finite amount of experimentation can weed out the infinite number of possible alternative hypotheses. (This particular observation goes all the way back to the logical positivists and before, but it was framed in its most strident form by Popper and Quine.)

That's why "replication" is a key factor in empirical science, but not in "logic"; it would be a very good idea for me (as a bench scientist) to replicate some of the classic findings in my field of study as part of my research program. On the other hand, I have no need to re-prove the classic logical findings, because logical findings are typically "sound" in the sense defined above; there's no possibility that Godel got his Completeness Theorem wrong, but there's a very definite possibility that Milliken got the mass of the electron wrong.

*Scratching head*

What can we miss with gravity for example?

Robin

20th September 2007, 04:44 PM

South Sydney are the greatest team in the history of sport.
I predict that meditating on this truth should bring me extreme happiness.
Meditating on this truth brings me extreme happiness.
Meditating on this trutn brings a lot of people extreme happiness.
South Sydney are the greatest team in the history of sport.

drkitten

20th September 2007, 05:27 PM

*
What can we miss with gravity for example?

Lots. For example, we currently believe that inertial mass and gravitational mass are the same thing (and that no object possesses one but not the other). We believe that mass is a constant barring changes in energy.

For that matter, we believe that an object, when dropped, will fall down. But no one actually knows whether my coffee cup will fall when dropped, because it's never been dropped. Perhaps I have the one magic coffee cup that doesn't fall.

We might be wrong (although that's not the way I would bet). All we have is a confident guess.

Tobermory

20th September 2007, 07:26 PM

I'll use 'iff' as an abbreviation for 'if and only if'

We're working with statements - strings of symbols that are considered to be 'well-formed' if they conform to a specified grammar. One such grammar is that of the first-order predicate calculus; another is that of the second-order predicate calculus. More on these later.

An interpretation of a statement or a set of statements provides meaning to the symbols in the statement(s). For every interpretation of a set of statements, each statement in the system is either true or false under that interpretation.

A statement that is true under every interpretation of the system is called a tautology.

A statement that is false under every interpretation of the system is called a contradiction.

A set of statements is consistent if it they don't imply a contradiction.

Pick a consistent set of well-formed statements and assume that they are true. This set is our set of axioms.

Some statements may exist that are true iff each of the axioms is true (under interpretation). These statements are called consequences of the set of axioms. These statements are also called theorems.

A set of axioms and the set of its theorems are called a theory.

Another important idea, besides consequence, is that of derivability.

A logical calulus is a set of procedures, a logical machine, for taking one or more statements and constructing new statements. It also provides the grammar that statements must conform to to be considered well-formed.

One such logical calculus is called the first-order predicate calculus (FOPC). Another logical calculus, the second-order predicate calculus (SOPC), enhances the first-order predicate calculus by adding in the ideas of 'for every' and 'there exists'.

Whenever we use the procedures of a logical calculus to construct a new statement from one or more existing 'input' statements, we say that we are deriving the new statement from the 'input' statements, and that the new statement is derived from the 'input' statements.

Which statements can we feed into the logical calculus machine? Any of the axioms and any statements which were derived from the axioms, directly or indirectly.

We will say that a statement is derivable iff there is a sequence of derivations that starts with the axioms and results in the construction of that statement.

A logical calculus is sound iff, for every set of axioms that conform to the calculus, every derivable statement is a consequence of that set of axioms.

In other words, given the input of axioms or theorems, a sound logical calculus can only construct theorems.

A logical calculus is complete iff, for every set of axioms that conform to the calculus, every theorem is derivable.

Goedel proved that the first-order predicate calculus is complete; that is, every true statement of a FOPC theory, every theorem, can be derived from its set of axioms. That impressed mathematicians.

Goedel then proved that the second-order predicate calculus is incomplete; that is, there exist SOPC theorems that can not be derived, statements that are true that can not be proved to be true.

Furthermore, Goedel proved that if you try to patch up the calculus so that this true statement becomes derivable, you inevitably result in a calculus that has other true statements that are not derivable. You can't ever, ever fix it. Any logical system of sufficient complexity has theorems that can't be proven.

This shocked the hell out of mathematicians.

I hope that this made some sense. I left out a lot and probably screwed something up.

I don't know if this question makes any sense, but I do know that you're the right person to ask. First, what exactly is the grammar of first-order predicate calculus; and second, how is one to be certain of its validity without proof of outcome?

(This is the first in a long string of questions I want to ask about your post, but I shall refrain from torturing you with the rest.)

RandFan

20th September 2007, 09:59 PM

Yes, why not?:)

Then I think we can supply you with an answer. Sorry I'm back so late. I see others might have already tackled this so I will first check it out.

Complexity

20th September 2007, 10:00 PM

I don't know if this question makes any sense, but I do know that you're the right person to ask. First, what exactly is the grammar of first-order predicate calculus; and second, how is one to be certain of its validity without proof of outcome?

(This is the first in a long string of questions I want to ask about your post, but I shall refrain from torturing you with the rest.)

Hi. By all means, ask what you like.

The three varieties of logic that I'll refer to are propositional (boolean) logic, first-order predicate calculus (FOPC) , and second-order predicate calculus (SOPC).

There are two boolean values: true and false.

A boolean variable can be assigned either boolean value.

Boolean expressions are formed from boolean variables and boolean values by using negators (nots), connectors (junctors; e.g. and, ors, exclusive-or, implies, is-equivalent-to) and parentheses. The first link provides a lot of information on boolean (propositional) logic.

First-order predicate calculus extends propositional logic by adding a universe of objects, variables that can can be assigned one of those objects, functions, predicates, and quantifiers that act over variables.

Consider the mini-world of geneology.

The universe of objects might be all of the people who have ever lived.

A variable named Dufus could be assigned any any of these people (e.g. 'Gerry').

A predicate is a special function of zero or more arguments that returns a boolean value. For example, IsFatherOf( Horatio, Ben ) returns true iff Horatio is the father of Ben.

IsDescendedFrom( Alice, Mary ) returns true iff Alice is descended from Mary.

AreParentsOf( Betty, Barney, BamBam ) returns true iff Betty and Barney are parents of BamBam.

A function that is not a predicate accepts zero or more arguments and returns an object from the universe of objects. For example, FatherOf( Ben ) should return Horatio.

There are two quantifiers, for-every and there-exists. In FOPC, quantifiers can only be applied to variables.

We can say, for example, that there exists an X such that IsFatherOf( X, Ben ) is true. We can be more general and say that, for every Y, there exists an X such that IsFatherOf( X, Y ) is true [[note: here there be dragons]].

In second-order predicate calculus, quantifiers can be applied to predicates and functions as well as variables. We can then say things like "For every function f, ..." and "There exists a predicate P such that, for every function f, ...".

This additional power is needed to express most of mathematics.

I think the first place to start is propositional (Boolean) logic. Here's a link that looks pretty good.

http://www.iep.utm.edu/p/prop-log.htm

The next level up in in logical power is the first-order predicate calculus, also known as first-order logic.

Here's a series of presentation screens:

http://www.cs.utexas.edu/~mooney/cs343/slide-handouts/fopc.4.pdf

The grammar for the first-order predicate calculus is given in screen 3.

The write-up of first-order logic in wikipedia covers a lot but it is a bit dense.

http://en.wikipedia.org/wiki/First-order_logic

There are external links that might be interesting at the end of that page.

This is all I had time for tonight, but it should give you a starting point.

Ask any questions that occur to you.

RandFan

20th September 2007, 10:10 PM

:rolleyes:

Jetleg, you've come to a very good place.

Mashuna

20th September 2007, 11:46 PM

To be completely honest - it seems to me that it is related to the fact, that I would love something not to be disproved in IS IT thread, and would love something to be proved in this thread.

But, nevertheless, my arguments seem to make sense to me in both of the threads, so I will not do an ad-hominem to myself.

I appreciate the honest answer here, thanks.

Complexity

21st September 2007, 12:19 AM

bluharmony - I'm thinking of writing up some tutorials on logic, starting with propositional (boolean) logic. I've got some time, and it would be fun, so I'll probably start on it in a day or two.

Propositional logic, boolean expressions, and all that sound trivial to many technically oriented people, but they aren't.

I've been working on some problems related to boolean expressions since 1986 - I did my master's and doctoral work on them (satisfiability determination and simplification). Both are problems I could spend the rest of my life on.

During graduate school, I focused on automated reasoning, also known as automated theorem-proving, using both first- and second-order predicate calculus. Northwestern was one of the centers for work in this area at the time.

While I was teaching, at around 1992, I started to focus on some of the challenging problems in graph theory, especially involving cliques. I never lost my interest in boolean expressions, however. It is just a matter of time, and what you work on first.

If you don't mind, I'll start with propositional logic, touch on some of the work that I've done with boolean expressions, and then move to first-order and then second-order predicate calculus. This will probably take many weeks, but I'll do my best to make some sense of things.

Since we're talking about mathematical logic, I'll start threads on the various logics under the Science and Math forum.

Please let me know in this thread of any topics you'd like to have covered or questions you'd like me to try to answer.

Thanks.

Tobermory

21st September 2007, 12:30 AM

Thanks, that sounds wonderful. Your explanation of boolean logic made what I'm doing when searching Westlaw explicitly clear. I also understand the other explanations you provided, but I would love to read more to feel completely comfortable. It's been ages since I've studied formal logic and mathematics, and those have always been interests of mine. I look forward to anything you put together on the topics, especially if your writing is as easy to follow as in the explanations above.

Complexity

21st September 2007, 12:33 AM

Cool. I'm psyched. I'll start outlining some stuff tomorrow morning.

Sometimes not working has its advantages.

RandFan

21st September 2007, 08:51 AM

Since we're talking about mathematical logic, I'll start threads on the various logics under the Science and Math forum.

Please let me know in this thread of any topics you'd like to have covered or questions you'd like me to try to answer.

Thanks.I would really like that. I'm not sure how much I can absorb but your writing style is pretty good for my level.

Thanks.

JetLeg

29th September 2007, 03:10 PM

JetLeg

29th September 2007, 03:13 PM

Lots. For example, we currently believe that inertial mass and gravitational mass are the same thing (and that no object possesses one but not the other). We believe that mass is a constant barring changes in energy.

For that matter, we believe that an object, when dropped, will fall down. But no one actually knows whether my coffee cup will fall when dropped, because it's never been dropped. Perhaps I have the one magic coffee cup that doesn't fall.

We might be wrong (although that's not the way I would bet). All we have is a confident guess.

We see that

Magnet is put near iron -> iron moves towards iron.
Therefore, magnet attracts iron.
And, we know that iron does not move by itself.

B occurs after A, and B does not occur by itself.

What else do we need to check? Is it enough?

Phlebas

29th September 2007, 03:14 PM

Eh...

Can you give me another example?

I don't get it, the structure of the argument seems perfectly plausible to me.

Sure, but if someone else makes the same argument about another team at the same time, it remains plausible, but you are left with a contradiction. You can't have two Greatest Team of All Time winners.

JetLeg

29th September 2007, 03:15 PM

NO ONE is exempt from bias.

NO ONE.

Do you think that asserting something and putting it in bold the best way to prove it?

JetLeg

29th September 2007, 03:19 PM

You said before that you can see a hammer, but you can't see logic. Well, compare the inferences to the world. Has it ever been that, for instance, the premises of the argument "p or q, ~p, so q" have been true, while the conclusion has been false. The system of proof here is simply looking at the world to see if there has been a case where this argument hasn't held. If not, we accept the argument as valid (and just like in science we accept that it may be falsified in the future, but so what).

Can you demonstrate in such a way, or in another that an argument from an authority is a fallacy?

For example, I say : everything that god says is right. Or, everything the dalai lama says is right.

How can you demonstrate it's a fallacy?

If you say "And what if god says 1+1=3?", I will reply - then we just have to reinterpret his sentence.

Phlebas

29th September 2007, 11:55 PM

If you say "And what if god says 1+1=3?", I will reply - then we just have to reinterpret his sentence.

Any statement can be correct if we're allowed to change the meaning of all the words.

Out of curiosity, JetLeg -- why do you post here? You don't seem to want to hear anything we have to say, and we can't see anything tangible in what you want to say. What is your goal when you come to this forum?

Smiledriver

30th September 2007, 12:46 AM

Logic is a description of the basic rules of thought. Does it describe thought well? Why do you want it proven?

JetLeg

30th September 2007, 03:35 AM

Any statement can be correct if we're allowed to change the meaning of all the words.

================================================== =
Can you give me an example ?
================================================== =

Out of curiosity, JetLeg -- why do you post here? You don't seem to want to hear anything we have to say, and we can't see anything tangible in what you want to say. What is your goal when you come to this forum?

================================================== =
Discussion
================================================== =

__

slingblade

30th September 2007, 08:58 AM

http://philosophy.hku.hk/think/logic/

cyborg

1st October 2007, 03:34 AM

Do you think that asserting something and putting it in bold the best way to prove it?

It is not a proof, it is a tautology.

blobru

1st October 2007, 04:57 AM

Can you demonstrate in such a way, or in another that an argument from an authority is a fallacy?
For example, I say : everything that god says is right. Or, everything the dalai lama says is right.
How can you demonstrate it's a fallacy?
...

Argument from authority is a fallacy because no one gets a free pass in logical debate. No one's infallible.
Even God has to "show his work". ;)

Yiab

1st October 2007, 01:00 PM

Can you demonstrate in such a way, or in another that an argument from an authority is a fallacy?

"Argument from authority" is, as I see it, a special type of "non sequitur". It says "statement A is true since authority B claims that A is true." Clearly B's claiming of A's truth in the preceding is irrelevant to the truth or falsehood of A.

Robin

1st October 2007, 01:19 PM

Eh...

Can you give me another example?

I don't get it, the structure of the argument seems perfectly plausible to me.
Plausibility is the secret of successful nonsense.

But if you can find an argument (or a structure) in what I wrote, please point it out to me. I see just the series of non-sequiturs I wrote.

drkitten

1st October 2007, 02:25 PM

We see that

Magnet is put near iron -> iron moves towards iron.
Therefore, magnet attracts iron.

Right there, you've already committed a fallacy.

For example, when I put a pencil a few inches above my desk and let go, my pencil will move toward the desk. That doesn't man that my desk attracts pencils. It only (visibly) attracts pencils in one direction (downward), but you would need to do more experiments (for example, holding the pencil a few inches below the desk) to learn that.

And, we know that iron does not move by itself.

No, we don't. All we know is that we've never seen it move by itself.

What else do we need to check? Is it enough?

Nowhere near enough.

JetLeg

1st October 2007, 05:37 PM

Right there, you've already committed a fallacy.

For example, when I put a pencil a few inches above my desk and let go, my pencil will move toward the desk. That doesn't man that my desk attracts pencils. It only (visibly) attracts pencils in one direction (downward), but you would need to do more experiments (for example, holding the pencil a few inches below the desk) to learn that.

Good example.

JetLeg

1st October 2007, 05:38 PM

Argument from authority is a fallacy because no one gets a free pass in logical debate. No one's infallible.
Even God has to "show his work". ;)

But how do you prove that?

JetLeg

1st October 2007, 06:29 PM

"Argument from authority" is, as I see it, a special type of "non sequitur". It says "statement A is true since authority B claims that A is true." Clearly B's claiming of A's truth in the preceding is irrelevant to the truth or falsehood of A.

It is unclear to me.

If I respect the person, it is even more unclear to me.

If I respect someone, it seems that I can say X is true, because he says so. And this seems a good epistemological criteria to me. So why do you think it is not a good one?

JetLeg

1st October 2007, 06:30 PM

Sure, but if someone else makes the same argument about another team at the same time, it remains plausible, but you are left with a contradiction. You can't have two Greatest Team of All Time winners.

But so far, there is no claim that contradicts the buddhist meditastion anatta claim.

blobru

1st October 2007, 07:18 PM

But how do you prove that?

In certain contexts, argument from authority is not a fallacy. For legal guilt, whatever the judge says [from the bench] is so. For Catholic doctrine, whatever the Pope says [ex cathedra] is so. They are acknowledged infallible authorities within their domains.
Outside those contexts, authority is always debatable. You can say I believe God's infallible and that's good enough for me, but people who don't don't have to agree with you, because your belief isn't proof. Thus you're committing a fallacy -- argument from authority they don't accept.

slingblade

2nd October 2007, 01:40 AM

In certain contexts, argument from authority is not a fallacy. For legal guilt, whatever the judge says [from the bench] is so.

I don't think so. Higher courts can overturn decisions from lower courts, and convicted defendants get appeals, so I'm not sure this makes a judge infallible within his or her domain.

For Catholic doctrine, whatever the Pope says [ex cathedra] is so.

For Catholics, yes. As you stipulate, in your next sentence:

They are acknowledged infallible authorities within their domains.

blobru

2nd October 2007, 02:04 AM

I don't think so. Higher courts can overturn decisions from lower courts, and convicted defendants get appeals, so I'm not sure this makes a judge infallible within his or her domain.

Yes, you're right -- "guilty" until another judge disagrees. The Supreme Court would be a better example for US law.

JetLeg

2nd October 2007, 05:11 AM

:)

Then I think we can supply you with an answer. Sorry I'm back so late. I see others might have already tackled this so I will first check it out.

RandFan,

How would you

-1- show that feelings that Dalai Lama tells the truth don't indicate that?
These feelings don't work for all the people, but they might work for him...

-2- show in general that an argument from authorirty is a fallacy?

cyborg

2nd October 2007, 05:32 AM

These feelings don't work for all the people, but they might work for him...

That pretty much there is the point.

show in general that an argument from authorirty is a fallacy?

If King Cnut tells the tide to go out does it obey him?

drkitten

2nd October 2007, 07:39 AM

But so far, there is no claim that contradicts the buddhist meditastion anatta claim.

Fine. Meditating on the fact that your buddhist medistatia anatta whatsis claim is gibberish makes me feel warm and fuzzy. Therefore your claim is in fact false.

Therefore, the same argument demonstrates your claim to be both true and false, hence the argument is fallacious.

drkitten

2nd October 2007, 07:41 AM

Yes, you're right -- "guilty" until another judge disagrees. The Supreme Court would be a better example for US law.

Except even the SCOTUS is demonstrably not infallible -- case in point, Plessy vs. Ferguson, which was specifically overturned by a later court.

drkitten

2nd October 2007, 07:51 AM

But how do you prove that?

It's easy enough to find false statements in the Bible if you want to prove God's fallability. The list of internal contradictions (who, exactly, killed Goliath? That one was so blatant that the KJV translators had to cheat on it....) and scientific inaccuracies (the waters "above"? The "storehouses of the snow"? Rabbits that chew their cud? Winged insects that "go on all fours"?) that it's quite reasonable to conclude that God is not infallible.

But beyond that -- there is no basis to conclude that God is infallable. Given that in general, argument from authority is a fallacy, on what basis (and from what evidence) do you infer that God should be an exception to the well-understood general rule? You're proposing the exception, YOU should have to justify it.

Especially when this "infallible" being tells us ("Genesis 30:37-39") that cattle who look at striped wooden rods will mutate.

JetLeg

2nd October 2007, 07:54 AM

It's easy enough to find false statements in the Bible if you want to prove God's fallability. The list of internal contradictions (who, exactly, killed Goliath? That one was so blatant that the KJV translators had to cheat on it....) and scientific inaccuracies (the waters "above"? The "storehouses of the snow"? Rabbits that chew their cud? Winged insects that "go on all fours"?) that it's quite reasonable to conclude that God is not infallible.

But beyond that -- there is no basis to conclude that God is infallable. Given that in general, argument from authority is a fallacy, on what basis (and from what evidence) do you infer that God should be an exception to the well-understood general rule? You're proposing the exception, YOU should have to justify it.

Especially when this "infallible" being tells us ("Genesis 30:37-39") that cattle who look at striped wooden rods will mutate.

I am not sure I think that the OT was inspired.

But - if god is omniscient, then he is infallible. Damn, you probably will want me to justify his omniscience...

slingblade

2nd October 2007, 11:00 AM

It is unclear to me.

If I respect the person, it is even more unclear to me.

If I respect someone, it seems that I can say X is true, because he says so. And this seems a good epistemological criteria to me. So why do you think it is not a good one?

President Bush.

Lots of people respected him, and still more respected his office.
He's said many, many things.

Have all his statements been true?

(hint: far fewer people today respect him, as seen by his approval ratings taking a nose-dive.)

blobru

2nd October 2007, 11:54 PM

Except even the SCOTUS is demonstrably not infallible -- case in point, Plessy vs. Ferguson, which was specifically overturned by a later court.

Does Brown v. Board of Education absolve Plessy?

But I get your point. Maybe infallible w.r.t. current interpretation of US law? (Although I see even that's subject to the Exceptions Clause; damn, strike three! Maybe-ee SCOTUS is a bad example. :) Can't think of any others... besides the Pope.)

RandFan

3rd October 2007, 01:09 AM

President Bush.

Lots of people respected him, and still more respected his office.
He's said many, many things.

Have all his statements been true?

(hint: far fewer people today respect him, as seen by his approval ratings taking a nose-dive.)

Appeal to authority (or simply someone respected is problematic).

I would only be interested in an appeal to someone who was an expert in his or her field and was respected by his or her peers.

drkitten

3rd October 2007, 09:13 AM

I am not sure I think that the OT was inspired.

Well, if you believe in "God" but don't believe in the OT, then right there you part company with almost everyone else who believes in "God." And at this point I have even less reason to take your "argument from authority" seriously, because the so-called authority that you cite is not recognized as an authority by anyone other than yourself.

But - if god is omniscient, then he is infallible. Damn, you probably will want me to justify his omniscience...

Damn straight. You're learning how the game is played. No unsupported hypotheticals cast as truths.

drkitten

3rd October 2007, 09:18 AM

Can't think of any others... besides the Pope.

That's because "infallibility" is generally recognized as a silly concept outside of religous circles. No human agency can be infallible, and even "divine" ones are usually administered by humans that make mistakes.

I'd, in fact, argue, that belief in "infallibility" is one of the marks that distinguish "cults" from "religons."

slingblade

3rd October 2007, 12:16 PM

Appeal to authority (or simply someone respected is problematic).

I know. We know. But JetLeg is convinced it's fully valid.

I would only be interested in an appeal to someone who was an expert in his or her field and was respected by his or her peers.

I used to make that exception--now, I'm not so sure. Even experts in their fields can be wrong.

A stupid Reganism is starting to make more sense to me these days, and that alone is scary as hell!

"Trust.....but verify."

cyborg

3rd October 2007, 12:40 PM

Even experts in their fields can be wrong.

Experts are frequently wrong - just like everyone else. We appeal to them as being less wrong on average than the non-expert.

Appeal to authourity is always a fallacy - but that doesn't matter so much in a debate if the debators are willing to agree on the validity of the authourity. Fallacy simply becomes premise.

JetLeg

3rd October 2007, 02:50 PM

I know. We know. But JetLeg is convinced it's fully valid.

I am still not sure how do you demonstrate it isn't valid.

slingblade

3rd October 2007, 02:52 PM

I am still not sure how do you demonstrate it isn't valid.

Well, honey, if you think everything you think, feel, hear, and see is true, then no one can demonstrate it to you.

articulett

3rd October 2007, 03:11 PM

jet lag-- there are FACTS--those are the things that are the same for everyone

And then there's everything else... those are things like court decisions, opinions, feelings, beliefs, mottos, ideals, stories, myths, delusions, illusions, hearsay, decrees, judgments, etc.

Facts are the things that don't need to be believed in or discussed to still be true. The earth is a sphere and was before humans knew it. Africa exists even if you don't believe it does. See the difference? I blame religion for the lack of clarity between the two for believers.

JetLeg

3rd October 2007, 03:21 PM

To which of my posts is it a reply, articulett?

slingblade

3rd October 2007, 03:39 PM

To which of my posts is it a reply, articulett?

What bloody difference does that make?

articulett

3rd October 2007, 03:41 PM

To which of my posts is it a reply, articulett?

Just about everything you say. You treat things that are not facts as though they should be measured like facts or disproved like facts. It might be a fact that you believe in god-- but that does not make your god a fact-- just your belief. Even if none of us believe in god--we can still understand that you really do. But you can't seem to understand that such a belief doesn't make your god real. Court decisions are opinions. It's a fact that an opinion was decided one way or the other-- but the decision itself is an opinion.

Someone may or may not have committed a murder. The verdict doesn't change the facts. The verdict is the decision that is supposed to best reflect the facts... Being found "not guilty" may make you "not guilty" in the eyes of the law-- but it has no affect on whether you actually ARE guilty or not.

I just see this all the time with religious people. They'll treat "all men are created equal" as the same type of statement as "the earth revolves around the sun". The former is an ideal; the latter is a claim of fact that can be tested and shown to be true or false. And even if we never tested it, it still would be a fact.

JetLeg

3rd October 2007, 03:50 PM

That's because "infallibility" is generally recognized as a silly concept outside of religous circles. No human agency can be infallible, and even "divine" ones are usually administered by humans that make mistakes.

I'd, in fact, argue, that belief in "infallibility" is one of the marks that distinguish "cults" from "religons."

God is usually said to be infallible.

slingblade

3rd October 2007, 04:26 PM

God is usually said to be infallible. So, all are cults to you?

Could be. (http://en.wikipedia.org/wiki/Cult_%28religious_practice%29)

articulett

3rd October 2007, 09:30 PM

What bloody difference does that make?

Aaack-- woo questions are the worst. They never want the answers-- they just want the attention ever on themselves. I must learn not to bite.

(they cannot compute; they cannot compute; they cannot compute)

slingblade

3rd October 2007, 09:37 PM

I guess so. You wouldn't believe the smell of my breath from having taken the bait so much.

drkitten

4th October 2007, 08:04 AM

God is usually said to be infallible.

Yes, but no sensible version of religion ascribes that infallibility even to our perceptions of Him. Quite the opposite, in fact, The Devil is notorious for passing himself off as God in order to corrupt mortals who believe that they are nevertheless perceiving God's will and doing God's work.

That's one of the lessons of Matthew 7:15 (and Luke 6:43). "Beware of the false prophets, who come to you in sheep's clothing, but inwardly are ravenous wolves. You will know them by their fruits. Grapes are not gathered from thorn bushes nor figs from thistles, are they? So every good tree bears good fruit, but the bad tree bears bad fruit."

"The good man brings good things out of the good stored up in his heart, and the evil man brings evil things out of the evil stored up in his heart."

Or, in other words, just because you feel it in your heart it doesn't make it good -- or true.

JetLeg

4th October 2007, 08:16 AM

Yes, but no sensible version of religion ascribes that infallibility even to our perceptions of Him. Quite the opposite, in fact, The Devil is notorious for passing himself off as God in order to corrupt mortals who believe that they are nevertheless perceiving God's will and doing God's work.

That's one of the lessons of Matthew 7:15 (and Luke 6:43). "Beware of the false prophets, who come to you in sheep's clothing, but inwardly are ravenous wolves. You will know them by their fruits. Grapes are not gathered from thorn bushes nor figs from thistles, are they? So every good tree bears good fruit, but the bad tree bears bad fruit."

"The good man brings good things out of the good stored up in his heart, and the evil man brings evil things out of the evil stored up in his heart."

Or, in other words, just because you feel it in your heart it doesn't make it good -- or true.

I do feel that organised religion implicitly implies our infallibilty to recognize that we believe in god and not in something else.

And I am still with the argument that it is arrogant to say that organized religion is wrong.

jond

4th October 2007, 08:26 AM

And I am still with the argument that it is arrogant to say that organized religion is wrong.

Another of my pet woo peeves:

Please explain how the statement "God created Man in his image" is not arrogant, while the statement "Humans are merely one of many many many species on earth, and earth is but one of many many many planets in this universe. Therefore humans really aren't very important in the universe" is arrogant. Please further explain how claiming to know the will of the creator of the universe is not arrogant, but not believing in a creator is arrogant.

Mashuna

4th October 2007, 08:46 AM

I do feel that organised religion implicitly implies our infallibilty to recognize that we believe in god and not in something else.

And I am still with the argument that it is arrogant to say that organized religion is wrong.

So is your feeling in this implicit implication enough? If they strengthened it, would you be happier with an explicit implication? Does organised religion agree with you, or is it still only something that you feel?

I'm with the argument that it's arrogant of you to say that I'm wrong to say that organized religion is wrong (let's see how long we can keep this going).

JetLeg

4th October 2007, 08:54 AM

RandFan

4th October 2007, 08:55 AM

I used to make that exception--now, I'm not so sure. Even experts in their fields can be wrong. Yes, they can be wrong but to not accept any expert testimony is an abuse of skepticism.

Anything is possible. We could be wrong about everything we know. It's unlikely though. I'll accept current understanding provisionally. I'll concede that the experts could be wrong but until then I'm willing to put a degree of trust into what they say.

That said, there is nothing at all wrong with questioning the experts and verifying what they say.

RandFan

4th October 2007, 08:57 AM

Jond, you say that saying the creator created us in his image is arrogant? You say that thinking that the place of humans in the universe is important- is arrogant? You think that claiming to know the will of the creator is arrogant? Did I get you right? I would agree, very strongly.

I said that it is arrogant to criticize organised religion, because it implies you are smarter than all the smart religious people, not because of your reasons.It implies nothing of the sort. I can see the problems inherent in religion regardless of the inteligence of any religious people. You've hit on a great big fallacy.

JetLeg

4th October 2007, 08:58 AM

Hm... Is claiming something is arrogant, therefore it is wrong a fallacy?

RandFan

4th October 2007, 08:59 AM

Hm... Is claiming something is arrogant, therefore it is wrong a fallacy?No. To conclude that one is arrogant because one is criticizing the beliefs of smarter people is a fallacy.

slingblade

4th October 2007, 09:04 AM

Hm... Is claiming something is arrogant, therefore it is wrong a fallacy?

First, define "fallacy." One must be able to define the terms one is using.

Darth Rotor

4th October 2007, 09:07 AM

I guess so. You wouldn't believe the smell of my breath from having taken the bait so much.
*Offers slingblade a stick of Trident(TM) spearmint sugarless gum.* :)

You made me spill some coffee, sling.

To which of my posts is it a reply, articulett?

What bloody difference does that make?
DR

drkitten

4th October 2007, 09:07 AM

No. To conclude that one is arrogant because one is criticizing the beliefs of smarter people is a fallacy.

To be fair, to claim that something is arrogant and therefore wrong is also a fallacy.

JetLeg

4th October 2007, 09:09 AM

No. To conclude that one is arrogant because one is criticizing the beliefs of smarter people is a fallacy.

Why ?

:confused:

slingblade

4th October 2007, 09:09 AM

*Offers slingblade a stick of Trident(TM) spearmint sugarless gum.* :)

You made me spill some coffee, sling.
DR

:D

jond

4th October 2007, 09:10 AM

Mashuna, with organised religion, I think they have the implicit idea that believers are infallible. Otherwise, how can they say that faith is infallible? Its not only about feeling.

Jond, you say that saying the creator created us in his image is arrogant? You say that thinking that the place of humans in the universe is important- is arrogant? You think that claiming to know the will of the creator is arrogant? Did I get you right?

I said that it is arrogant to criticize organised religion, because it implies you are smarter than all the smart religious people, not because of your reasons.

Correct. It is arrogant (IMO) to suggest that humans are somehow special creatures.

Criticizing organized religion has nothing to do with whether or not I'm smarter than they are, only that they're claiming things that they can't back up with evidence. And worse, they're acting on those beliefs which negatively impacts the lives of others who don't belive the same way.

drkitten

4th October 2007, 09:11 AM

I do feel that organised religion implicitly implies our infallibilty to recognize that we believe in god and not in something else.

Well, good for you. Come back when you have a rational argument to defend that "feeling," because just reading it, it strikes me as unbelievably irrelevant to the point of irrationality.

"I do feel that major league baseball implicitly implies our persecution in belleving that Paris is the capital of France and not of Gemany."

And I am still with the argument that it is arrogant to say that organized religion is wrong.

Good. You've called me arrogant. You've called me a name. But I'm still not wrong -- and organized religions is still not right.

Let's suppose that I'm self-admittedly the most arrogant person in the world (which itself would be further proof of my arrogance). I tell you that I make good pizzas. Does that mean that my pizzas are bad?

drkitten

4th October 2007, 09:16 AM

Why ?

:confused:

Because the argument can lead from a true premise to a false conclusion.

I play trivial pursuit on Wednesday nights with Richard Dawkins, Stephen Hawking, Murray Gell-Mann, and Albert Einstein. I'm by far the dumbest player in the room. I always lose. But Albert doesn't get them all right, either. if Albert tells me that he believes that the capital of Colorado is Boulder, and I tell him that it isn't, that doesn't make me arrogant. After all, he's a physicist, not a geographer.

JetLeg

4th October 2007, 09:17 AM

To be fair, to claim that something is arrogant and therefore wrong is also a fallacy.

Can you show why?

JetLeg

4th October 2007, 09:20 AM

Eh...

A way of thinking which is wrong?

JetLeg

4th October 2007, 09:25 AM

Well, good for you. Come back when you have a rational argument to defend that "feeling," because just reading it, it strikes me as unbelievably irrelevant to the point of irrationality.

"I do feel that major league baseball implicitly implies our persecution in belleving that Paris is the capital of France and not of Gemany."

Organised religion does imply that when we feel god, we can be sure we do not feel the devil. Morever, it assumes that the only explanation for our feelings is that these feelings are related to god, and that there is no other explanation. I think the latter assumes omniscience implicitly - it assumes that we can be absolutely sure that we are right, and there is no other explanation for our feelings.

JetLeg

4th October 2007, 09:27 AM

if Albert tells me that he believes that the capital of Colorado is Boulder, and I tell him that it isn't, that doesn't make me arrogant. After all, he's a physicist, not a geographer.

Hm... This example does make sense. Can you give me some more please?

slingblade

4th October 2007, 09:28 AM

Because emotions are subjective. Logic tends to be objective and deal with objective constructs. One can't feel or emote a logical construct.

If A, then B;
A;
Therefore B

doesn't care how you feel about it! It doesn't derive its correctness or incorrectness from my feelings about it. I don't want to commit a fallacy of absolutes, but in general, logic doesn't function emotionally, and emotions don't function logically.

This will probably backfire on me, but let's see how it pans out:

I'm currently taking care of my mother full-time. She's dying. With each passing day, she gets a little worse. Her life expectancy is, at this moment, about 4 months (give or take).

When she does die, what, logically speaking, would you expect her daughter to feel?

JetLeg

4th October 2007, 09:31 AM

Good. You've called me arrogant. You've called me a name. But I'm still not wrong -- and organized religions is still not right.

Hm... Is there a specific fallacy of "name calling"?

drkitten

4th October 2007, 09:31 AM

Organised religion does imply that when we feel god, we can be sure we do not feel the devil.

No, it specifically denies that. Protestantism, in particular, makes a point of telling its followers to check the feelings in our heart against Scripture, because the devil is capable of creating such feelings. Similarly, Buddhism and Hinduism are very sharp about the way that our feelings can get in the way of God, hence the need for medidation and to get past our "feelings" precisely because they are not infallible.

Morever, it assumes that the only explanation for our feelings is that these feelings are related to god, and that there is no other explanation.

Not only mainstream Christianity does it not assume this, it explicilty denies that -- and provides a specific other explanation (desires that are planted by the Devil). O

So the "factual" basis on which your argument rests is wrong; "organized religion" does not have the attributes you describe.

drkitten

4th October 2007, 09:32 AM

Hm... Is there a specific fallacy of "name calling"?

Yes. Argumentam ad hominem.

drkitten

4th October 2007, 09:34 AM

Hm... This example does make sense. Can you give me some more please?

I can give you lots. I won't, because I needn't bother. One example suffices to show the fallacious nature of the reasoning employed. Look up the technical meaning of "fallacy" sometime.

JetLeg

4th October 2007, 09:36 AM

When she does die, what, logically speaking, would you expect her daughter to feel?

Please, let us discuss an example that is less personal for you. I don't feel comfortable. Give me a similar one.

JetLeg

4th October 2007, 09:38 AM

Yes. Argumentam ad hominem.

Is saying

That is a fascist thing to say! That is anti-democratic! That is not liberal!

A type of ad hominem?

slingblade

4th October 2007, 09:42 AM

Someone bring in the Great Big Giant Spoon! Hurry!

slingblade

4th October 2007, 09:43 AM

Please, let us discuss an example that is less personal for you. I don't feel comfortable. Give me a similar one.

I can't. I can't ever give you an example that isn't personal to me, because emotions are personal to the person feeling them.

Are you getting a hint now?

JetLeg

4th October 2007, 09:44 AM

Let's suppose that I'm self-admittedly the most arrogant person in the world (which itself would be further proof of my arrogance). I tell you that I make good pizzas. Does that mean that my pizzas are bad?

No. But it is a reason to be more skeptical of your eveluation of your pizzas.

JetLeg

4th October 2007, 09:49 AM

I can't. I can't ever give you an example that isn't personal to me, because emotions are personal to the person feeling them.

Are you getting a hint now?

With regards to your example, there is a certain probability of feelings after death of mother. A feeling of grief is much more probable than the feeling of lust.

drkitten

4th October 2007, 09:52 AM

No. But it is a reason to be more skeptical of your eveluation of your pizzas.

Therefore, just because something is arrogant does not make it wrong -- ergo, "it is arrogant, therefore it is wrong" is a fallacy.

Name-calling by itself is not a fallacy, because it's not an argument (when someone cuts me off in traffic and I call him a ^&*%&^*, I'm not trying to establish the truth of a proposition). But if you say "That is a fascist thing to say! That is anti-democratic! That is not liberal!" as an argument against what someone is saying, then, yes, it is ad hominem.

And fallacious. If Mussolini himself said that the capital of France is Paris, that doesn't make him wrong.

JetLeg

4th October 2007, 09:53 AM

I can give you lots. I won't, because I needn't bother. One example suffices to show the fallacious nature of the reasoning employed. Look up the technical meaning of "fallacy" sometime.

I agree that you don't have to show the nature of the reasoning, but I am quite used to thinking the argument about the arrogance. Your example was a surprise. Due to that, I am asking for some more examples.

drkitten

4th October 2007, 09:55 AM

Someone bring in the Great Big Giant Spoon! Hurry!

Sigh. It's my job. I read "indoor work with no heavy lifting" and decided that having to spoonfeed critical thinking to adolescents was worth it.

Although I must admit it would be a relief to be able to use the Great Big Giant Spoon here. I feel I'm using a coffee stirrer....

JetLeg

4th October 2007, 10:02 AM

Therefore, just because something is arrogant does not make it wrong -- ergo, "it is arrogant, therefore it is wrong" is a fallacy.

Name-calling by itself is not a fallacy, because it's not an argument (when someone cuts me off in traffic and I call him a ^&*%&^*, I'm not trying to establish the truth of a proposition). But if you say "That is a fascist thing to say! That is anti-democratic! That is not liberal!" as an argument against what someone is saying, then, yes, it is ad hominem.

And fallacious. If Mussolini himself said that the capital of France is Paris, that doesn't make him wrong.

I think that when someone says "That is anti-democratic", it implies the sentence "Whatever is anti-democratic is wrong". So that makes it more of an unfounded assumption than an ad hominem. Agree?

slingblade

4th October 2007, 10:04 AM

With regards to your example, there is a certain probability of feelings after death of mother. A feeling of grief is much more probable than the feeling of lust.

That's where this backfires on me, because she isn't dead yet. Unless I am feeling the specific emotions at this moment, it would be disingenuous of me to project my possible feelings and declare them my actual feelings.

However, I think about it all the time, and were she to die today, my chief emotions would be relief and happiness. I am grieving today. I grieved yesterday. But were I to go into the living room right now and find her dead, I'd smile. I'd be so happy. Just thinking about her death brings a smile to my face. That doesn't seem logical, on its face, but its true for me. I want my mother to die soon, so her suffering--which increases daily and cannot be alleviated--will end. And when it ends, I predict I will feel relief and happiness, but not grief. Yet, again, that's disingenuous. I'm predicting, not experiencing.

My point, ultimately, is that logic doesn't often dictate emotional states. Emotions do. And since emotions are subjective and vary from person to person, they can't be used as a foundation for a sound and valid logical argument.

Other people, in my exact place, would grieve horribly. Are they wrong, logically? Am I wrong, logically?

It's impossible to say. Emotions are too personal and too subjective to quantify logically.

Mashuna

4th October 2007, 10:05 AM

I think that when someone says "That is anti-democratic", it implies the sentence "Whatever is anti-democratic is wrong". So that makes it more of an unfounded assumption than an ad hominem. Agree?

In general, people only use the term anti-democratic when referring to social or political issues. The only person I've seen use it when referring to logic is you. They're different issues.

cyborg

4th October 2007, 10:06 AM

In general, people only use the term anti-democratic when referring to social or political issues. The only person I've seen use it when referring to logic is you. They're different issues.

Argument ad populam surely?

slingblade

4th October 2007, 10:11 AM

Sigh. It's my job. I read "indoor work with no heavy lifting" and decided that having to spoonfeed critical thinking to adolescents was worth it.

Although I must admit it would be a relief to be able to use the Great Big Giant Spoon here. I feel I'm using a coffee stirrer....

I know. I understand. We can start a chorus of sighs, if that helps.

The subject is too massive to dole out in tiny portions on a forum thread. I've given him websites to read that deal with logic, but I don't know if he even clicks, much less reads. The evidence seems to point to "not even once," but it's scanty.

I personally prefer it when folks undertake to educate themselves, with a little help from others. I don't like it much when they expect me to do all the hard work, and I don't find it effective for either party.

Oh, well. Let the chorus begin.

JetLeg

4th October 2007, 10:18 AM

[QUOTE=slingblade;3027209]

QUOTE]

You are saying that emotions don't fit into a theory that is able to predict them. Am I right in understanding you?

drkitten

4th October 2007, 10:38 AM

I think that when someone says "That is anti-democratic", it implies the sentence "Whatever is anti-democratic is wrong". So that makes it more of an unfounded assumption than an ad hominem. Agree?

No, I disagree. It's still an ad hominem, simply an ad hominem with an implicit step. As you point out, the speaker intends for the listener to react as though the implied statement "whatever is anti-democratic is wrong" were also expressed. The implied sentence contains -- and is intended to contain -- an ad hom.

drkitten

4th October 2007, 10:46 AM

I agree that you don't have to show the nature of the reasoning, but I am quite used to thinking the argument about the arrogance. Your example was a surprise. Due to that, I am asking for some more examples.

You're confusing "intelligence" with "knowledge" and "reason." John Nash is arguably one of the smartest people alive today, but he knows less about the best spot for an underage person to buy beer in Ocean City, MD than half the graduating class of Ocean City High.
So he's probably going to get wrong what half the class -- and possibly the dumber half at that -- of seventeen year olds will get right. Is it arrogant for them to recognize that?

Similarly, a lot of people will believe stuff without any actual basis, simply because it's what they've been taught. Half that same clase "knows" that if you put sugar in a gas tank, the car won't work -- and that powered car windows will short out if you drive into water by accident. They're probably even taught the second in drivers' ed class. Well, the Mythbusters tested 'em both, and they're both "busted." Doesn't stop people from believing them. And if John Nash took the same drivers' ed class, he probably believes them, too. Having watched the show, I don't think it's arrogant of me to believe he's wrong if he does.

Very smart people can also simply be deluded. I picked Nash for a reason; he's certifiably schizophrenic. This means that, despite his intelligence, he provably believes things that aren't true.

Religion is like that. Lots of people -- including very smart people -- are taught to believe in God as children. But being taught something as a child doesn't make it true, although in many cases you will spend the rest of your life believing that it is. But what's the actual evidence? In terms of physical evidence, there is essentially none. In terms of logical evidence, there is also essentially none. All there is is a vague emotional "feeling" that some people have -- a feeling of no evidentiary value that we can even reproduce in the lab via brain manipulation.

So it works out to the WMD-in-Iraq issue again. There's just no credible evidence -- no objective reason to believe. And the arguments made by the believers are uniformly unconvincing.

slingblade

4th October 2007, 11:00 AM

You are saying that emotions don't fit into a theory that is able to predict them. Am I right in understanding you?

That's part of what I'm telling you, yes. The other part is that emotions can rarely be quantified and qualified as "right" or "wrong," "correct" or "incorrect," and "logical" or "illogical."

I am aware that, in general, the emotions I anticipate feeling at my mother's death are not the ones usually expected when we lose someone we love. And I do love my mother, very much. But I'm doing my crying over it right now, and daily. I'm feeling my anger over losing her, right now. I'm a mess. She hurts; I hurt. We are both in pain.

When she is gone, that pain will end for both of us, and I anticipate feeling much better. That doesn't mean I'm right. And none of it is or can form the basis for a sound and valid logical argument.

Someone brought in the Not So Big Giant Spoon, so I'll use it. You like examples. That's helpful. Here's one:

Emotions and feelings have their places. Absolutely. But they make lousy reasons for objectivity. Emotions operate for a limited audience. Logic operates for anyone.

Postulating a god that exists because you feel it exists creates a god for only you. In order for it to exist for everyone and anyone, it has to be proven to exist. Your feelings about it are not sufficient.

One of your first few threads--if not the first--formed an argument thusly:

A. I respect and admire the Dalai Lama.
B. I cannot respect and admire anyone who lies.
Therefore, everything the Dalai Lama says is true.

I don't mean to put words in your mouth, so do correct the above statements to better state what you were arguing, if I got it wrong.

Posters here began to respond, trying to show you that the above is not a valid or sound argument. They introduced you to concepts like fallacies and unfalsifiability. You appear to have taken those concepts and are running with them, but with a faulty understanding of them, or how they work.

We've tried to show you, for the above example, that since you cannot have heard or read every single word spoken by (nor been a party to every single thought of) the DL, you cannot ever say, for certain, the man has never told a lie, lied by ommission, or simply has been mistaken and misspoken. That to go on your "feeling" that he's a good man, and good men don't lie, therefore he always speaks truth, is unsound in content (not true), and invalid in form.

We've tried to show you that your feelings are fine for you, and that you have every right to believe what you want about the DL, even if you are wrong. But we don't feel what you feel, and don't believe what you believe. Your argument is illogical to most of us, and would be to most folks who understand the philosophy and concepts of logical argument.

You're taking a dog, and trying to make it a cat by saying, "Look, it has four legs, fur, is a human companion animal, eats food from a can, and loves me. My cat does all that, too, so I believe this dog is a cat."

And we're telling you, "Go ahead and believe it, but it's not."

Studying logic, educating yourself about it, will help you see that. I'm just sure of it.

JetLeg

4th October 2007, 11:05 AM

What is intelligence if not the continual application of knowledge and reason?

drkitten

4th October 2007, 11:07 AM

What is intelligence if not the continual application of knowledge and reason?

The sporadic application of knowledge and reason.

I.e. smart people can do dumb things.

JetLeg

4th October 2007, 11:08 AM

Slingblade, when you fall in love with someone - I doubt that you think logicaly about it. You just fall in love, and believe the qualities that your falling in love has ascribed to him.

JetLeg

4th October 2007, 11:09 AM

(to him - to the person you fell in love with)

JetLeg

4th October 2007, 11:11 AM

A smart person is a person that does smart things, by definition. So he can he do dumb things?

slingblade

4th October 2007, 11:13 AM

A smart person is a person that does smart things, by definition. So he can he do dumb things?

Every day.

And I don't necessarily agree yours is the definition of "smart."

slingblade

4th October 2007, 11:16 AM

Slingblade, when you fall in love with someone - I doubt that you think logicaly about it. You just fall in love, and believe the qualities that your falling in love has ascribed to him.

Yep, that's generally correct. I did give much more thought to the second person I married, because experience taught me caution. We lived together for five years before getting married, to "be sure this time." But there wasn't much logic to the experience of falling in love with him, no.

It was a feeling. As they teach us in nursery school these days, "feelings just are."

That's why feelings don't support logical arguments very well.

drkitten

4th October 2007, 11:36 AM

A smart person is a person that does smart things, by definition. So he can he do dumb things?

Absolutely. Or else no one is smart at all, because no one is smart all the time.

Go to the smartest person you know, and ask her if she's ever done anything dumb in her life. Then listen for the laugh....

I actually had a conversation like that once, a few months ago. My ten-year-old niece was in a school play, and was worried about messing up on-stage. I told her, "Honey, everyone messes up on-stage. The good actors are the ones that don't do it very often and that don't let it bother them when they do." I mentioned that her father was a very good salesman, and that even he had a sales presentation tank from time to time.

Her mother -- my sister -- looked at me with this look of stunned horror in her eyes and said "My husband has NEVER had a sales meeting tank in his life."

So I asked him, later, over dinner. Now, this guy is a super salesman; he could sell brooms to desert nomads, reading glasses to the blind, and Nazi regalia at a Greenpeace rally. He should be; he's not only talented, but he's experienced; he's been doing this for something like twenty years.

So when I asked him "have you ever had a sales presentation tank?" he laughed uproariously. Of course he has. He treated us to twenty minutes of amusing war stories, all at his own expense, of just how badly he had messed up at various times.

But he's still a very good salesman.

Oh, and my niece did fantastically at her performance. As the female lead, no less....

Complexity

4th October 2007, 12:14 PM

A smart person is a person that does smart things, by definition. So he can he do dumb things?

Not true, and not 'by definition'.

articulett

4th October 2007, 05:00 PM

Jetlag, you are terribly confused about what is factual and "everything else" (opinions, beliefs, mottoes, decisions, judgements,myths, fables, metaphors, feelings, faith, beliefs, delusions, parables, illusions, blather, dramas, examples, etc.). Facts are the things that are the same for everybody no matter what they believe. You don't have to believe facts for them to be true. The earth was spherical even when people believed it was flat.

When you speak of organized religion--certainly you realize you are really talking about a huge number of beliefs that really aren't the same religion to religion or, even, person to person. In fact, if any single religion WERE correct, that means that the vast majority of believers are WRONG. If Mohummed truly was a prophet, than Jesus is not God. If the Mormons are right, you can't go to the highest heaven. Etc.

And what is it you imagine they'd be correct about? None of them offer anything measurable or tangible-- there's nothing to distinguish one faith from another in regards to truth. And by truth I mean the one that is the same for EVERYBODY.

It's not arrogant to say that there is no measurable evidence supporting any organized religious belief, because THERE IS NO MEASURABLE EVIDENCE supporting any organized religious belief!! What do you think there is evidence for? There is no more evidence for Christianity than there is for Scientology. There is no more evidence that Mormons have the truth than that the Muslims have the truth. But members of every sect arrogantly assume they DO have the truth-- Now THAT is arrogance.

The answer to how humans got here is the same for all humans even though humans have believed many different things about the subject through the eons. The facts don't show any god-- sure, a god could be behind it all... but he would have to be cruel and wasteful and inefficient. No scriptural miracles like virgin births or talking snakes are verifiable in any way. Whether one can experience anything without a brain is a truth that is the same for everyone. Lots of people have different opinions about what happens after you die, but the facts don't care about your or what anyone wants to happen. And so far, there is no evidence to suggest that there are ANY kinds of conscious beings that don't have a brain-- not parsley, bacteria, dead people... no ghosts, souls, spirits, demons, incubi, succubi, Thetans, engrams, gods, devils, hobgoblins, sprites, or pixies. All notions involving any of these concepts are unsupported notions-- they can only be supported by faith, confirmation bias, and arrogance.

No matter how arrogant you think it is, the facts are the same-- and the facts are that there is no measurable evidence for any of the stuff organized religions proffer as higher truths. Your thinking it's arrogant, doesn't change the facts. Your opinions and assessment of the situation doesn't change the facts either. The only thing that could change the facts would be actual measurable evidence show that consciousness of some sort can exist outside of a living brain-- that's why JREF has the MDC. If anyone ever can prove something supernatural including "consciousness absent a brain", there's money available to that person... and scientists can begin honing our understanding of the topic just like we have with DNA.

Until that time, one myth is as useful as any other in regards to actual "truth". All attempts at claiming the JREF prize just highlight the fact that people are really super good at tricking themselves-- yet when tested scientifically with controls in place for the known ways humans fool themselves and/or others--they perform no better than chance.

RandFan

4th October 2007, 05:04 PM

To be fair, to claim that something is arrogant and therefore wrong is also a fallacy. Did I do that? If so then I'm sorry. Leave it to me. :)

Darth Rotor

4th October 2007, 05:04 PM

Yes. Argumentam ad hominem.
drkitten, it seems to me that Argumentam ad hominem is "you are wrong because you are a doodyhead" whereas "you are a doodyhead" is simply name calling.

Simple name calling isn't any form of argument at all.

DR

drkitten

4th October 2007, 05:13 PM

drkitten, it seems to me that Argumentam ad hominem is "you are wrong because you are a doodyhead" whereas "you are a doodyhead" is simply name calling.

Simple name calling isn't any form of argument at all.

Check the context, Darth. We're specifically discussing "this is arrogant, therefore it's wrong," which is indeed ad hominem.

RandFan

4th October 2007, 05:16 PM

Hm... Is claiming something is arrogant, therefore it is wrong a fallacy?
No. I'm wrong. It is a fallacy.

:o :(

Oh, look over there.

Darth Rotor

4th October 2007, 05:17 PM

Check the context, Darth. We're specifically discussing "this is arrogant, therefore it's wrong," which is indeed ad hominem.

Got it, if the connotation of "arrogant" is negative.

Thanks.

DR

drkitten

4th October 2007, 05:27 PM

Oh, look over there.

A three-headed monkey!

JetLeg

5th October 2007, 12:23 AM

Every day.

And I don't necessarily agree yours is the definition of "smart."

What is you definition of smart? I think saying that a smart person is a one that does smart things is reasonable enough.

JetLeg

5th October 2007, 12:54 AM

No, I disagree. It's still an ad hominem, simply an ad hominem with an implicit step. As you point out, the speaker intends for the listener to react as though the implied statement "whatever is anti-democratic is wrong" were also expressed. The implied sentence contains -- and is intended to contain -- an ad hom.
(indented by me)

Where is the ad hom? The implied statement "Whatever is anti-democratic is wrong" is not a personal accusation.

With regards to statements such as "He is wrong because he is stupid" - It seems quite plausible that stupid people will be wrong, at least much more plausible than they will be wrong than smart people. So if someone is stupid, that increases the probability that he is wrong. Even if it is classified as an ad hominem, it seems a reasonable statement to me.

Mashuna

5th October 2007, 01:02 AM

(indented by me)

Where is the ad hom? The implied statement "Whatever is anti-democratic is wrong" is not a personal accusation.

With regards to statements such as "He is wrong because he is stupid" - It seems quite plausible that stupid people will be wrong, at least much more plausible than they will be wrong than smart people. So if someone is stupid, that increases the probability that he is wrong. Even if it is classified as an ad hominem, it seems a reasonable statement to me.

Wait, so giving someone a reason why they're wrong is arrogant, but saying that someone is wrong because they are stupid is a reasonable statement? :confused:

JetLeg

5th October 2007, 02:02 AM

You're confusing "intelligence" with "knowledge" and "reason." John Nash is arguably one of the smartest people alive today, but he knows less about the best spot for an underage person to buy beer in Ocean City, MD than half the graduating class of Ocean City High.
So he's probably going to get wrong what half the class -- and possibly the dumber half at that -- of seventeen year olds will get right. Is it arrogant for them to recognize that?

Similarly, a lot of people will believe stuff without any actual basis, simply because it's what they've been taught. Half that same clase "knows" that if you put sugar in a gas tank, the car won't work -- and that powered car windows will short out if you drive into water by accident. They're probably even taught the second in drivers' ed class. Well, the Mythbusters tested 'em both, and they're both "busted." Doesn't stop people from believing them. And if John Nash took the same drivers' ed class, he probably believes them, too. Having watched the show, I don't think it's arrogant of me to believe he's wrong if he does.

Very smart people can also simply be deluded. I picked Nash for a reason; he's certifiably schizophrenic. This means that, despite his intelligence, he provably believes things that aren't true.

Religion is like that. Lots of people -- including very smart people -- are taught to believe in God as children. But being taught something as a child doesn't make it true, although in many cases you will spend the rest of your life believing that it is. But what's the actual evidence? In terms of physical evidence, there is essentially none. In terms of logical evidence, there is also essentially none. All there is is a vague emotional "feeling" that some people have -- a feeling of no evidentiary value that we can even reproduce in the lab via brain manipulation.

So it works out to the WMD-in-Iraq issue again. There's just no credible evidence -- no objective reason to believe. And the arguments made by the believers are uniformly unconvincing.

I agree that Nash can be misonformed. But if you criticize his logic, then it implies you are smarter than him, and you can't do that.

cyborg

5th October 2007, 03:44 AM

But if you criticize his logic, then it implies you are smarter than him, and you can't do that.

'Smart' is simply being right. If his logic's not right he's not being smart is he?

drkitten

5th October 2007, 08:25 AM

But if you criticize his logic, then it implies you are smarter than him,

No, it doesn't. People make mistakes in logic. (See Wason's three-card task for examples.)

Do good quarterbacks throw interceptions? According to Sports Illustrated, every NFL starting quarterback has already thrown at least one interception this season -- and these are the best in the business. A good quarterback isn't one who never throws interceptions. He's one who doesn't throw them often.

Do good kickers miss field goals? Five kickers haven't missed a field goal yet this year. Shall we say that those are the only five good kickers in the world? If Jeff Reed misses one next year, does that drop the total to four good kickers?

JetLeg

5th October 2007, 02:48 PM

No, it doesn't. People make mistakes in logic. (See Wason's three-card task for examples.)

Do good quarterbacks throw interceptions? According to Sports Illustrated, every NFL starting quarterback has already thrown at least one interception this season -- and these are the best in the business. A good quarterback isn't one who never throws interceptions. He's one who doesn't throw them often.

Do good kickers miss field goals? Five kickers haven't missed a field goal yet this year. Shall we say that those are the only five good kickers in the world? If Jeff Reed misses one next year, does that drop the total to four good kickers?

Yes, but religion is something extremely important in someone's life. So when you criticize something that is that important in the life of a smart person, that he builds a large part of his life around, does it imply then that you are smarter than him?

drkitten

5th October 2007, 02:59 PM

Yes, but religion is something extremely important in someone's life.

Not throwing interceptions is very important in a quarterback's life. Sometimes it's the difference between gainful employment and starvation. Abstractions like "eternal salvation" pale in importance next to the idea that you won't have a job next week because you've been benched and cut. Just because something is important doesn't mean that people don't make mistakes.

I gave the example upthread of my brother-in-law, the salesman. He's a smart guy. And selling is important to him, for the same reason (he has a wife and two kids to feed). But he still makes mistakes. Why?

In fact, it's well documented that people often make more mistakes about important matters, precisely because the stakes are so high. Sometimes you'll hear this called things like "choking under pressure."

So when you criticize something that is that important in the life of a smart person, that he builds a large part of his life around, does it imply then that you are smarter than him?

No, it simply implies that I believe that he made an important mistake.

JetLag, I don't know how may different ways I have left to say "No" politely to you.

No, criticizing someone does not imply that I think I am smarter than him. Not under any imaginable circumstances. Re-posing the question with an even more far-fetched hypothetical will not change the "no" into a "yes." The biggest fool in the world can say the sun is shining, but that doesn't make it dark out. Similarly, the smartest man in the world can tell me that it's Tuesday, but that doesn't make it so. The smartest person in the world can be disproved by the dumbest piece of paper in the world -- if that piece of paper happens to be a calendar.

People make mistakes. No one is so intelligent that they never make a mistake. (Actually, I find -- and Albus Dumbledore supports me on this -- that the smarter people are the ones who make correspondingly bigger mistakes. They make fewer mistakes, but because they are so used to not making mistakes, they tend not to notice when they do and therefore make huge ones.) And just because i point out that you have made a mistake does not make me smarter than you -- it just means that I didn't make that particualr mistake.

drkitten

5th October 2007, 03:06 PM

Where is the ad hom? The implied statement "Whatever is anti-democratic is wrong" is not a personal accusation.

Yes, but the term ad hominem is still used. And it's still a fallacy because "anti-democratic" is unrelated to the truth or falsity of a statement.

Actually, I'm not sure I agree with you here. I don't see how a proposition (remember that only propositions are true or false) can be democratic or anti-democratic. Propositions don't vote.

With regards to statements such as "He is wrong because he is stupid" - It seems quite plausible that stupid people will be wrong, at least much more plausible than they will be wrong than smart people. So if someone is stupid, that increases the probability that he is wrong. Even if it is classified as an ad hominem, it seems a reasonable statement to me.

"Reasonable statements" can still be fallacious. (I told you earlier to look up "fallacy.") The problem is that the biggest fool in the world can say the sun is shining, but that doesn't make it dark out. Just because something is "likely to be" true doesn't make it true. And

JetLeg

7th October 2007, 05:15 AM

Yes, but the term ad hominem is still used. And it's still a fallacy because "anti-democratic" is unrelated to the truth or falsity of a statement.

Actually, I'm not sure I agree with you here. I don't see how a proposition (remember that only propositions are true or false) can be democratic or anti-democratic. Propositions don't vote.

"Reasonable statements" can still be fallacious. (I told you earlier to look up "fallacy.") The problem is that the biggest fool in the world can say the sun is shining, but that doesn't make it dark out. Just because something is "likely to be" true doesn't make it true. And

Were the last few words of your post cut out?

JetLeg

18th October 2007, 06:54 AM

Because the argument can lead from a true premise to a false conclusion.

I play trivial pursuit on Wednesday nights with Richard Dawkins, Stephen Hawking, Murray Gell-Mann, and Albert Einstein. I'm by far the dumbest player in the room. I always lose. But Albert doesn't get them all right, either. if Albert tells me that he believes that the capital of Colorado is Boulder, and I tell him that it isn't, that doesn't make me arrogant. After all, he's a physicist, not a geographer.

(Bold added by me)

You say that if a certain form of argument can lead from a true premise to a false conclusion, then it is always wrong.

But I am not sure that it is always wrong for [I]all/I] subjects. A certain form of argument (an appeal to popular opinion) might be wrong, when it comes to physical objects, but not wrong when it comes to immaterial entities.

You are disproving a certain form of argument by using a material example -> shape of earth (not flat) is the one you used. But it might be that material an immaterial subjects are just so different that you cannot conclude from the inability to use a certain form of argument for one - to another.

Belz...

18th October 2007, 10:49 AM

Yes, but religion is something extremely important in someone's life. So when you criticize something that is that important in the life of a smart person, that he builds a large part of his life around, does it imply then that you are smarter than him?

Useless distinction. "Important" is relative.

drkitten

18th October 2007, 12:00 PM

You say that if a certain form of argument can lead from a true premise to a false conclusion, then it is always wrong.

Exactly wrong. I say that if a certain form of argument can lead from a true premise to a false conclusion, then it is always fallacious. That's because fallacy means "a form of argument that can lead from a true premise to a false conclusion." Fallaciouis arguments can have true conclusions, but only by chance, since the truth or falsity of the conclusion is more or less independent of the truth of the premises.

Furthermore, I will also state that if a certain form of argument can lead from a true premise to a false conlcusion, then that argument is always unreliable, which means we cannot rely on it as a method of obtaining truth.

A certain form of argument (an appeal to popular opinion) might be wrong, when it comes to physical objects, but not wrong when it comes to immaterial entities.

Yes, and that's another fallacy -- "special pleading" -- because it can lead from true premises to false conclusions. And, as a fallacy, it's unreliable and can be safely disregarded by a rational observer.

But it might be that material an immaterial subjects are just so different that you cannot conclude from the inability to use a certain form of argument for one - to another.

And here we have another fallacy, that of "argument from ignorance." Yes, it is indeed possible that any random sentence happens to be true -- I can put my pet kittten at the computer keyboard and the string of keys she hits might be a true sentence. It might be that my desk drawer is filled with gold bricks. But that "might be" can also lead from true premises to false conclusions, and is therefore fallacious, unreliable, and to be disgarded by a rational observer.

You'll need to do much better than a collection of fallacies. If you want to make any statements that will not be immediately ignorable about your hypothetical immaterial being, you better back them up with either evidence (of which you admit you have not) or valid (i.e. reliable, non-fallacious) reasoning. So far, you have done neither.