Quotes About Logic

Intuition,' he answered with a shrug. 'It is the only tool left to the mathematician in the absence of proof.

To make the worse appear the better reason.

Since we think we understand when we know the explanation, and there are four types of explanation (one, what it is to be a thing; one, that if certain things hold it is necessary that this does; another, what initiated the change; and fourth, the aim), all these are proved through the middle term.

It is absurd to hold that a man ought to be ashamed of being unable to defend himself with his limbs but not of being unable to defend himself with speech and reason, when the use of reason is more distinctive of a human being than the use of his limbs.

If then it be possible that one contrary should exist, or be called into existence, the other contrary will also appear to be possible.

Nor does the argument about the contrary seem to be well urged. It does not follow, they say, because pain is an evil, that pleasure is a good; for the opposite to evil may be not a good, but some other evil, and both evil and good may stand opposed to something which is neither one nor the other.

There are, then, these three means of effecting persuasion. The man who is to be in command of them must, it is clear, be able (1) to reason logically, (2) to understand human character and goodness in their various forms, and (3) to understand the emotions--that is, to name them and describe them, to know their causes and the way in which they are excited.

Thought is required wherever a statement is proved, or, it may be, a general truth enunciated.

We ought to be able to persuade on opposite sides of a question; as also we ought in the case of arguing by syllogism: not that we should practice both, for it is not right to persuade to what is bad; but in order that the bearing of the case may not escape us, and that when another makes an unfair use of these reasonings, we may be able to solve them.

Now all orators effect their demonstrative proofs by allegation either of enthymems or examples, and, besides these, in no other way whatever.

A man who has been well trained will not in any case look for more accuracy than the nature of the matter allows; for to expect exact demonstration from a rhetorician is as absurd as to accept from a mathematician a statement only probable.

Rhetoric is the counterpart of logic; since both are conversant with subjects of such a nature as it is the business of all to have a certain knowledge of, and which belong to no distinct science. Wherefore all men in some way participate of both; since all, to a certain extent, attempt, as well to sift, as to maintain an argument; as well to defend themselves, as to impeach.

A statement is persuasive and credible either because it is directly self-evident or because it appears to be proved from other statements that are so. In either case it is persuasive because there is somebody whom it persuades.

All proofs rest on premises.

Law is mind without reason.

Philosophy is the science which considers truth.

Whatever cannot be seen, conceived at once, thru simple reasoning is humbug, and not science!

LEGGE DI KATZ Uomini e nazioni agiranno razionalmente solo dopo aver esaurito ogni altra possibilità.

There is evidence that as we become less exposed to opposing viewpoints, we become less logically competent as people.

You know my methods, Watson.

I can do some of the number puzzles.

Puzzles are always a difficult thing, I don't think I've played any games where the puzzles are perfectly contextualised, unless the entire game is a puzzle game built upon that concept.

For me, the peculiar qualities of faith are a logical outcome of this level of biological organization.

It is not of the essence of mathematics to be conversant with the ideas of number and quantity.