What is it for something to be logical?

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Theaetetus
 
Reply Thu 10 Dec, 2009 08:48 pm
@kennethamy,
All that it takes for a logical conclusion is that it follows from its premises. Thus, the moon can be made of green cheese according to logic if the premise lead to that conclusion. Logical validity has nothing to do with the truth of a conclusion other than it follows from the premises.
 
Reconstructo
 
Reply Thu 10 Dec, 2009 08:58 pm
@kennethamy,
But the thread is entitled "what does it take for something to be logical?"

The word "logic" has done a lot of duty over the centuries. If the premises aren't investigated for "truth value," then logic is a toy, however shiny. Therefore my suggestion that "logical" is often just an adjective of praise for rhetoric we find persuasive......

This is not to deny propositional logic. I've programmed computers. Boolean variables are fairly simple to work with their TRUE or FALSE values. Much of the philosophy that matters has created new concepts, new metaphors with which to interpret both the world and the philosophers preceding the invention of these concepts/metaphors.

Metaphor is generally associated with rhetoric, and "rhetoric" is generally a pejorative term. I don't agree with this attitude. Others are, as always, free to go their own way.
 
Locke phil
 
Reply Thu 10 Dec, 2009 09:11 pm
@Reconstructo,
I agree with Reconstructo in the term that Logical is more or less an opinion someone has depending on whether or not something is persuasive.

I believe that logical is something that has more facts, or more things proving it than there are things disproving it. However, this does have to do with persuasion.

Even with something that is not true, you can find facts about it to use in an argument or if you are trying to persuade someone. If I said, "The spoon is silver," someone could easily say "In our perspective, it is silver. But if we went to a different planet with different substances and lighting, it could very well be blue. Does that make it blue? Or is it still silver?"

I believe that logic is based on how persuasive it and its supporters are about it. But with actions, logic is still based on persuasion, but it is also heavily influenced by morals. But with both actions we take, and facts about things, logic is also influenced by the current situation and surroundings.
 
Reconstructo
 
Reply Thu 10 Dec, 2009 09:42 pm
@Locke phil,
Locke;110011 wrote:
I agree with Reconstructo in the term that Logical is more or less an opinion someone has depending on whether or not something is persuasive.

I believe that logical is something that has more facts, or more things proving it than there are things disproving it. However, this does have to do with persuasion.

Even with something that is not true, you can find facts about it to use in an argument or if you are trying to persuade someone. If I said, "The spoon is silver," someone could easily say "In our perspective, it is silver. But if we went to a different planet with different substances and lighting, it could very well be blue. Does that make it blue? Or is it still silver?"

I believe that logic is based on how persuasive it and its supporters are about it. But with actions, logic is still based on persuasion, but it is also heavily influenced by morals. But with both actions we take, and facts about things, logic is also influenced by the current situation and surroundings.



When you say that logic is heavily based on morals, I agree at least with what I think you mean. For me, the word "persuasion" includes moral considerations. The word persuasion etymologically traces back to force. Then of course we have the word emotion, obviously hinting at motion.

Logic could also be described as an ideal sort of persuasion, one that is sprinkled with the holy water of its abstinence from trope, and various other more complicated aspects of human communication.

I like to compare logic to a priest as I also enjoy the metaphor "truth is a woman."

---------- Post added 12-10-2009 at 10:58 PM ----------

I fear that some have misunderstood me to be an irrationalist. As I've said before, it was my passion for epistemology (as well as Nietzsche) that led me to question the will-to-truth itself. What is logic for? Is it not an attempt at a higher purer form of persuasion? Of course I think it has also been understood as the structure of thought itself. Hegel, for instance, seems to be of this mind. I don't think any account of the structure of thought is viable that neglects metaphor, that womb of so much that is worth opening books for.
 
Camerama
 
Reply Thu 10 Dec, 2009 10:12 pm
@kennethamy,
kennethamy;109803 wrote:
So many threads ask whether this or that is logical. Is probabllity logical? Are moral arguments logical? And so on. I never know what it is being asked by such questions. Is there something clear and specific that is being asked by the question, is X logical? What is it?



Logic is deductively eliminating contadictions, and arriving at a "true" primary, respective to the axiom existence exists. Or as Ayn Rand puts it, "non-contradictory identification." In reality, contradictions cannot exists i.e an apple cannot be an orange at the same time or in the same respect. Saying an apple is an apple and an orange at the same time, is a contradiction in identity.

Ex.) All Dogs chew bones.
Chip is a dog.
Therefore Chip chews bones.
The third statement is logical, providing the validity of the Syllogism's major premise.

The goal of logic is "true" knowledge, based on the facts of reality. It is the tool of reason.

---------- Post added 12-10-2009 at 11:29 PM ----------

Locke;110011 wrote:
I agree with Reconstructo in the term that Logical is more or less an opinion someone has depending on whether or not something is persuasive.

This is nonsense. In no way is logic subjective. Logic is the product of natural laws and facts of reality. To say it is governed by rhetoric is to deny any foundation of knowledge. It is to say that A is B, it is to undercut the law of identity. It is to say that fire is water, if "I" say so. It is to say i can drink crude oil instead of water.

Locke;110011 wrote:
I believe that logical is something that has more facts, or more things proving it than there are things disproving it. However, this does have to do with persuasion.


Logic is absolute, there is no compromise, there is no psuedo-truth. There is true, and there is false. Humans are made up of cells. 2+2=4. These are facts of reality, and to deny them is to accept falsities.

Locke;110011 wrote:
Even with something that is not true, you can find facts about it to use in an argument or if you are trying to persuade someone. If I said, "The spoon is silver," someone could easily say "In our perspective, it is silver. But if we went to a different planet with different substances and lighting, it could very well be blue. Does that make it blue? Or is it still silver?"


The identity of the spoon is a referent to it's reality in "THIS" world. I don't know much about color spectrum, i don't know if it is a universal law, but it's identity pertains to earth.


Locke;110011 wrote:
I believe that logic is based on how persuasive it and its supporters are about it. But with actions, logic is still based on persuasion, but it is also heavily influenced by morals. But with both actions we take, and facts about things, logic is also influenced by the current situation and surroundings.


So might is right. If the majority said 2+2=5, it makes it true. Majority reserves the power to distort reality? It is not power in number, but power in reason, power in thought.

---------- Post added 12-10-2009 at 11:31 PM ----------

Theaetetus;110001 wrote:
All that it takes for a logical conclusion is that it follows from its premises. Thus, the moon can be made of green cheese according to logic if the premise lead to that conclusion. Logical validity has nothing to do with the truth of a conclusion other than it follows from the premises.


And, a false conclusion means a false premise. That is the power of logic
 
Reconstructo
 
Reply Fri 11 Dec, 2009 12:48 am
@kennethamy,
No offense, Camerama, but can you prove anything you said? How is it that logic is the product of natural laws and facts of reality?

Are you familiar with antecedent skepticism? When was logic invented, or is it an intangible entity? Or was mankind without the means of truth until the invention of logic?

You say "Logic is absolute, there is no compromise, there is no psuedo-truth. "
Do you realize how religious this sounds?

Have you really considered how the words "true" and "reality" are used among human beings? Do you think we are especially focused on the non-controversial aspects of reality, such 2+2 = 4? Or could we perhaps we talking about the sort of reality that is in dispute at this very moment?

Do you claim to have the one right and true view? If so, does this not remind you of the many many religious fanatics out there? This is not to call you a fanatic. But I was enthusiastic about Rand once, and still respect her ethics. But I think her epistemology is faulty and also that her style is arrogant and pseudo-prophetic. This is not to deny what is good in her.

If Ayn Rand defines "man as a heroic being," is this logically provable or rather a statement of value? And if the opening of her credo is a non-logical statement of value, does this cast doubt on her later assertion that reason is man's only absolute?

Respectfully,
recon
 
jeeprs
 
Reply Fri 11 Dec, 2009 04:37 am
@Reconstructo,
I agree with many of the points Camerama makes which are in accordance with formal logic. Within specific terms of reference, such terms are irrefutable. The point where they break down is that reality is often not so neat, not so easy to reduce to logical units. There are many life situations where some of the premisses are impossible to determine, or the connections between the premisses are impossible to ascertain, or value judgements are involved. So that even though the 'Aristotlean' approach of formal logic is impeccable, as far as it goes, it turns out to be not that useful in all circumstances, or only completely accurate, in some circumstances (which adds up to the same thing).

I think this the perspective that Reconstructo is introducing. However I don't believe it can be taken too far.

Under no circumstances will I ever agree that what is logical is a matter of opinion. There begins madness (or admission to the French philosophy department, whichever comes first.)
 
kennethamy
 
Reply Fri 11 Dec, 2009 06:50 am
@Theaetetus,
Theaetetus;110001 wrote:
All that it takes for a logical conclusion is that it follows from its premises. Thus, the moon can be made of green cheese according to logic if the premise lead to that conclusion. Logical validity has nothing to do with the truth of a conclusion other than it follows from the premises.



Validity is said to be "truth-preserving". Which is to say it preserves truth from the premises to the conclusion. If the premises of an argument are true, then, if the argument is valid, then necessarily, the conclusion is true. And, in fact, by the same token, validity preserves falsity from the conclusion to the premises, since, if an argument has a false conclusion, then, if the argument is valid, then, necessarily, one or more of the premises is false. (The Hindu god of logic, is Vishnu, The Preserver).

So validity ( in deductive logic) does have something to do with truth (and with falsity). Validity guarantees the preservation of truth (from premises to conclusion) and falsity (from conclusion to premises).

Of course, in non-deductive logic, there is no such thing as validity at all.

So, what you mean by saying that validity has nothing to do with the truth conclusion must be that validity is independent of the truth of the conclusion, because a valid argument may have a true or a false conclusion, and an invalid argument may have a true or false conclusion. So that just from the premise that an argument is valid (invalid) nothing follows about the conclusion.
 
Camerama
 
Reply Fri 11 Dec, 2009 11:15 am
@kennethamy,
Logic is only possible in reality with reason, independent of some illusory fantasy world. To deny logic(from a valid premise) is to deny truth and to deny truth is to deny knowledge. You describe a world void of any static realism, prone to indeterminable flux, and inconsistent change.The degree to which we understand metaphysics is translatable(can't think of the right word) to the degree to which aquire true knowledge. No, not all theories are infallible, but the foudnations they rest on are. Existence exists, the law of identity, consciousness,(compliments of the cartesian stronghold where your antecedent skepticism was born) all axiomatic, all irrefutable. That is not fanaticism, that is reality. It is a philosophy based on reason, rather than randomness and self doubt. Logic is a tool in the discovery of truth. Reality is absolute, therefore you must concede "true" logic is absolute. Denying logic is denying reality. You truly believe there is a dualism in reality? What reality is it you are disputing?
 
kennethamy
 
Reply Fri 11 Dec, 2009 11:20 am
@Camerama,
Camerama;110200 wrote:
. To deny logic(from a valid premise) is to deny truth



Could you explain what you mean by that? It is exactly that kind of use of the term, "logic" I find bewildering, and why I started this thread.
 
Camerama
 
Reply Fri 11 Dec, 2009 12:06 pm
@kennethamy,
Haha okay taht was a bit presumptuous and what seems like a huge logical jump in itself. There are a few factors limiting the statement. To justify it, I want to make it clear i was speaking deductively, and assuming the Major Premise and Minor Premise were truths. Under these conditions, to deny logic is to deny the existence of truth. To deny consistent logic distorts the reality of truth. Not as much bang in these terms.
 
kennethamy
 
Reply Fri 11 Dec, 2009 12:25 pm
@Camerama,
Camerama;110220 wrote:
Haha okay taht was a bit presumptuous and what seems like a huge logical jump in itself. There are a few factors limiting the statement. To justify it, I want to make it clear i was speaking deductively, and assuming the Major Premise and Minor Premise were truths. Under these conditions, to deny logic is to deny the existence of truth. To deny consistent logic distorts the reality of truth. Not as much bang in these terms.


But you haven't told me what you mean by "deny logic". And that is what I don't understand, and why I am complaining.
 
Zetherin
 
Reply Fri 11 Dec, 2009 12:30 pm
@kennethamy,
kennethamy;110230 wrote:
But you haven't told me what you mean by "deny logic". And that is what I don't understand, and why I am complaining.


He may mean by "deny logic" that something is illogical. And what he means by illogical may be, "The conclusion does not follow from the premises".
 
kennethamy
 
Reply Fri 11 Dec, 2009 12:47 pm
@Zetherin,
Zetherin;110232 wrote:
He may mean by "deny logic" that something is illogical. And what he means by illogical may be, "The conclusion does not follow from the premises".


Could be. There are so many things he may mean. And, as Reconstructo says, he may just mean he doesn't like the argument, maybe because he doesn't like the conclusion. Of course, that is what I am complaining about.
 
Camerama
 
Reply Fri 11 Dec, 2009 12:56 pm
@kennethamy,
I was contending Reconstructo's interpretation of logic, i wanted him to clarify the impact of persuasion on truth, and his idea that there is no absolute reality in a world of change. That is how i interpreted his post and mine was a response to it. I saw him as subordinating logic to whim and subjectivity. I however, believe there is a reality completely independent of humanity, and there will be after we are gone. This may be a diversion from the original topic, but is not irrelevant, since metaphysics is the fundamental premise for any argument.
 
kennethamy
 
Reply Fri 11 Dec, 2009 01:01 pm
@Camerama,
Camerama;110241 wrote:
I was contending Reconstructo's interpretation of logic, i wanted him to clarify the impact of persuasion on truth, and his idea that there is no absolute reality in a world of change. That is how i interpreted his post and mine was a response to it. I saw him as subordinating logic to whim and subjectivity. I however, believe there is a reality completely independent of humanity, and there will be after we are gone. This may be a diversion from the original topic, but is not irrelevant, since metaphysics is the fundamental premise for any argument.


But what you wrote about "denying logic" does not seem to have anything to do what R. said about truth. I am not a mind-reader. How could I tell that from what you wrote?
 
Emil
 
Reply Fri 11 Dec, 2009 01:33 pm
@Zetherin,
Zetherin;110232 wrote:
He may mean by "deny logic" that something is illogical. And what he means by illogical may be, "The conclusion does not follow from the premises".


"Illogical" typically means "contrary to the rules of logic".

It is funny/sad that the nonsense writers invaded the very thread their nonsense!
 
Reconstructo
 
Reply Fri 11 Dec, 2009 01:48 pm
@kennethamy,
1. Of course there is a reality outside us.
2. We can't afford to be too whimsical. Life is dangerous. Bad judgment kills.
3. We interpret sense-data by means of language, and the language we use with ourselves and others is connected with emotion.
4. We must examine the nature of the language we use. "Words are wise men's counters but the money of fools. "
5. Is much of what is called logic founded on questionable axioms? For instance, should we consider Hegel's criticism of the Law of Excluded Middle?
6. Is it more realistic and "logical" to describe man as a being with purposes other than the truth itself? Is it naive to think that man decides what is true based on some cold pure dialectic? Or does motive factor into any logical (methodical, thorough) epistemology?
7. That metaphor has been traditionally relegated to rhetoric rather than logic is logic's loss. Metaphor is how our abstract words are created in the first place. Logic is the child of Rhetoric. Logic is a sacrifice of depth for accuracy, of practicality for certainty. If logic is chess, rhetoric is war.
 
kennethamy
 
Reply Fri 11 Dec, 2009 02:07 pm
@Reconstructo,
Reconstructo;110269 wrote:
1.
5. Is much of what is called logic founded on questionable axioms? For instance, should we consider Hegel's criticism of the Law of Excluded Middle?


Nah!.................
 
Reconstructo
 
Reply Fri 11 Dec, 2009 02:17 pm
@kennethamy,
I find Freud persuasive when he says (in many more words) that the truth manifests itself in jokes.......

Load up your squirt guns with holy water! Raise a flag upon which an equals sign is scrawled in the blood of effective orators!!
 
 

 
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