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As far as I can see, the core principle at the base of logic is the avoidance of contradiction. Every logical deduction gives us a conclusion, the negation of which would be a contradiction. The ultimate test of whether a conclusion is logically valid is that (given the definitions of the terms you have used) its negation would involve a contradiction.
I just came across this and thought it might prove entertaining.
[INDENT]:eek: 38 Ways To Win An Argument
by Arthur Schopenhauer
,,,etc.[/INDENT]
As far as I can see, the core principle at the base of logic is the avoidance of contradiction. Every logical deduction gives us a conclusion, the negation of which would be a contradiction. The ultimate test of whether a conclusion is logically valid is that (given the definitions of the terms you have used) its negation would involve a contradiction.
Yeah I bookmarked that somewhere. It's not to be taken seriously. :rolleyes:
Aristoddler,
To be taken seriously if one realizes a persons ability with language and concepts can be used in a negative way, to frustrate the honest communication of another.It is basically and profoundly dishonest.Attacking the person instead of the subject is all to common,I wonder though if it really was Schopenhaur who is the source of said material,that I find doubtful as well.It may be something to take note of, in order that you not fall victum too such tactics
Winning an argument has nothing to do with logic. It concerns debating and rhetoric (the art of persuasion). The merit of an argument is not measured by its capacity to persuade, but by its capacity to establish its conclusion.
All dogs are mammals.
All poodles are dogs.
Therefore, all poodles are mammals.
The negation of the conclusion, all poodles are dogs is, some poodles are not dogs. But that is not a contradiction.
Perhaps you mean something different-this:
If an argument is deductively valid, then if the conclusion is negated, the set which consists of the premises and what is now the negation of the conclusion, forms an inconsistent set of statements. Is that what you have in mind?
The conclusion of your syllogism is actually "All poodles are mammals." I am referring to the negation of the whole of that conclusion, which would read: It is not true that all poodles are mammals. Given the premisses you supply this would be a contradiction.
What do you think of my substantive point that logic is essentially elaborations on the Law of Noncontradiction?
Peter
I think there is some truth in the quote.
Yes Logic can be fallible, but in most cases it is correct.
Hence within Logic one can find the security at least of being able to be right with confidence as much as being wrong with confidence.
Logic can provide the sense of security (emphasis on 'sense') of being surely right or surely wrong.
I don't which to offend anyone, but identity is essential to logic and syllogism is only an attempt at establishing an identity. Certainly, it has weaknesses, and is easily manipulated; but because it is so easy, it is practiced by every child to a greater or lesser extent, and so the accumulation of identities, definitions, really can begin and continue without any formal training in logic, which is more the processes by which identities are handled to add to knowledge. It is easy to see that children learn through a variety of methods to tell the difference between things, and I think it is easy to to see that syllogism and identity, like information accepted on faith plays a part. What part in ratio I cannot say. I can say that people reach a level of inductive and deductive reasoning with a great deal of formed knowledge.
I don't want to seem as ignorant as this statement may make me seem; but until a few years ago I had no concept of identity or conservation, as two sides of the same fuzz ball, until working it out in public on one of these forums. That does not mean I did not have the concept of identity conservation; I just did not have all the details formally. Children work out identity of objects in reality through syllogism every time they learn to distinguish between cats and dogs, even while each has more in common than not. Once one is presented with a formal idea, whether it is correct or not is unimportant, because then one can prove or disprove it, as one cannot ever do with an unformed concept. Does that make sense?
But consider the syllogism:
All snakes are reptiles
All cobras are snakes
Therefore, all cobras are reptiles.
This syllogism is sound because it has all true premises, and is valid (i.e. the conclusion follows necessarily from the premises). Therefore, the syllogism has a true conclusion.
But there is not one identity statement contained in the syllogism. Neither the premises, nor the conclusion assert an identity. So I cannot understand why you say that the syllogism tries to establish an identity.
At every step in the process identity is evident: Snakes, Cobras, and reptiles. That is why syllogism was the great fancy of the middle ages; because there desire was to classify... everything. Reptiles is the genus, and snakes are the phylum, and cobras a species. What do they have in common and what sets them apart? Even though syllogism is not an exacting tool as it takes too much for granted it does present a hypothetical identity that can be challenged, so, it is a step.
Identity between what and what? What two things are supposed to be identical. Are you sure you know what "identity" means?
Careful with personal affronts...challenge the idea, not the person please.
~Ari
Lol...well I'd say everytime a relgious fanatic tries to prove the existence of God 'because the Bible says so' etc... or the multitude of other reasons they come up with are all examples of fallible logic.
But then again on the other hand, we can't logically DISprove the existence of God.
The only difference is: logical people can ADMIT they can't logically disprove the existence of God whilst illogical people do NOT admit that they can not logically prove the existence of God.
Sure I'm sure. A is A is an example of identity. Conservation is another sense of identity. Every word in the dictionary is a sense of identity. The concept is fundamental to logic. Let me give you an example. A 'line' is a concept. If you have a line, and you add four feet and subtract two inches you have lengthened and then shortened the line, but you have in no sense affected the fact that it is a line. When you hear of physical terms like conservation of motion or charge, you may be dealing with different physical properties, but the conserved quality is of a conceptual understanding essential to the thing's identity. In the example of Piaget's work with cognitive development in children, the understanding of conservation on a practical level was thought of as a milestone. When a child learned that water poured into a tall thin glass was not more than before, or in a short fat glass was not less, then the child was ready for greater rational challenges. Does this make sense?
But lets stick to what you claimed. I don't want to go all over the place, and I don't understand a lot of what you write, anyway. For instance, I don't think that the sentence, "Every word in the dictionary is a sense of identity" means anything in English. Same with "conservation is an identity" It makes no sense to say of something (or of a word) that it is "an identity". An identity is a dyadic relation between two things. Now, where is the identity statement in the syllogism I gave as an example? None of the three statements state an identity. A statement of identity would be, "Mark Twain is identical with Samuel Clemens", or, "the predecessor of the number, 4, is identical with the successor of the number 2". To say that A and B are identical is to say that A and B are one and the same. None of the statements of the syllogism says anything is identical with anything else. So you seem to be wrong.
You seem to mean using logic badly. That doesn't mean that logic is fallible any more than it means that arithmetic is fallible if you don't add or subtract correctly.
Its the person who uses logic incorrectly who is fallible, not logic.