Quotes About Logic

Science is what you know, philosophy is what you don't know

Mathematics rightly viewed possesses not only truth but supreme beauty.

This [Hegel's philosophy] illustrates an important truth, namely, that the worse your logic, the more interesting the consequences to which it gives rise.

The true function of logic ... as applied to matters of experience ... is analytic rather than constructive; taken a priori, it shows the possibility of hitherto unsuspected alternatives more often than the impossibility of alternatives which seemed prima facie possible. Thus, while it liberates imagination as to what the world may be, it refuses to legislate as to what the world is

Persecution is used in theology, not in arithmetic, because in arithmetic there is knowledge, but in theology there is only opinion.

Philosophy is an unusually ingenious attempt to think fallaciously.

If everything has a cause, then God must have a cause. If there can be anything without a cause, it may just be the world as God...

Logic was, formerly, the art of drawing inferences; it has now become the art of abstaining from inferences, since it has appeared that the inferences we feel naturally inclined to make are hardly ever valid.

All definite knowledge—so I should contend—belongs to science; all dogma as to what surpasses definite knowledge belongs to theology. But between theology and science there is a No Man's Land, exposed to attack from both sides; this No Man's Land is philosophy.

Grammar and ordinary language are bad guides to metaphysics. A great book might be written showing the influence of syntax on philosophy.

Berkeley retains the merit of having shown that the existence of matter is capable of being denied without absurdity.

Hume is thus led to the view that, when we say 'A causes B', we mean only that A and B are constantly conjoined in fact, not that there is some necessary connection between them.

Perfect rationality consists, not in believing what is true, but in attaching to every proposition a degree of belief corresponding to its degree of credibility.

In a man whose reasoning powers are good, fallacious arguments are evidence of bias.

Thus mathematics may be defined as the subject in which we never know what we are talking about, nor whether what we are saying is true.

The argument is really no better than that. There is no reason why the world could not have come into being without a cause; nor, on the other hand, is there any reason why it should not have always existed. There is no reason to suppose that the world had a beginning at all. The idea that things must have a beginning is really due to the poverty of our imagination.

All definite knowledge -- so I should contend -- belongs to science; all dogma as to what surpasses definite knowledge belongs to theology. But between theology and science there is No Man's Land, exposed to attack from both sides; this No Man's Land is philosophy.

His most important books are his two Logics, and these must be understood if the reasons for his views on other subjects are to be rightly apprehended.

Hegel thought that, if enough was known about a thing to distinguish it from all other things, then all its properties could be inferred by logic. This was a mistake, and from this mistake arose the whole imposing edifice of his system. This illustrates an important truth, namely, that the worse your logic, the more interesting the consequences to which it gives rise.

to justify any such inference.

Every proposition which we can understand must be composed wholly of constituents with which we are acquainted.

Any logically coherent body of doctrine is sure to be in part painful and contrary to current prejudices

We are uttering a mere tautology if we mean by 'in the mind' the same as by 'before the mind', i.e. if we mean merely being apprehended by the mind.

To preach an altruistic morality appears to me somewhat useless, because it will appeal only to those who already have altruistic desires. But to preach rationality is somewhat different, since rationality helps us to realize our own desires on the whole, whatever they may be.