Logic Quotes

500+ Sourced quotes

Almost all thinking people agree that you should not have probability 1 (or 0) for any event, other than one demonstrable by logic, like 2 x 2 = 4.

You can be totally rational with a machine. But if you work with people, sometimes logic often has to take a backseat to understanding.

Cooking like everything else in France is logic and fashion.

Discovery in mathematics is not a matter of logic. It is rather the result of mysterious powers which no one understands, and in which unconscious recognition of beauty must play an important part. Out of an infinity of designs, a mathematician chooses one pattern for beauty's sake and pulls it down to earth.

Since reasoning, or inference, the principal subject of logic, is an operation which usually takes place by means of words, and in complicated cases can take place in no other way: those who have not a thorough insight into both the signification and purpose of words, will be under chances, amounting almost to certainty, of reasoning or inferring incorrectly.

John Stuart Mill

What renders a problem definite, and what leaves it indefinite, may best be understood from mathematics. The very important idea of solving a problem within limits of error is an element of rational culture, coming from the same source. The art of totalizing fluctuations by curves is capable of being carried, in conception, far beyond the mathematical domain, 65 where it is first learned. The distinction between laws and coefficients applies in every department of causation. The theory of Probable Evidence is the mathematical contribution to Logic, and is of paramount importance.

Consequently he who wishes to attain to human perfection, must therefore first study Logic, next the various branches of Mathematics in their proper order, then Physics, and lastly Metaphysics.

One of the best things to come out of the home computer revolution could be the general and widespread understanding of how severely limited logic really is.

Unlike Hegel's progress model of history, which moves by stages, each containing its own logic of growth and decline, the economic model develops as the simple function of one money-variable over time, with a long-term trend which increases monotonically.

Better to be without logic than without feeling.

Charlotte Brontë

Grove quotes me – and the quotes are things I actually said! That is stunningly rare. … What liberals normally do in response to a principled conservative argument is lie, manufacture quotes, and call conservatives names – as some dissolute drunk did in the New York Post a few days later. The left's logic deficit is a topic I explore thoroughly in my book. Buy it and prepare to have your blood run hot.
Oh, and for the record, Howard Kurtz is wrong about the reason I call him the Liberal Ombudsman for Liberal Media Bias in my book – it was not the "girly-boy" quote. Paradoxically, that is the ONLY time Kurtz has quoted me accurately.

Formal logic and the logical syllogism encapsulate connectedness in reasoning.

Marshall McLuhan

Not only the tools of manual labour, but also the tools of human thought — words — are subject to the laws of historical development. The history of the meanings of words is outside the area of interest of formal logic, and could not be fruitfully studied by the methods of that discipline.

Witold Doroszewski

This type of paradox is quite characteristic of Zen. It is an attempt to "break the mind of logic".

Douglas Hofstadter

According to this view, the sentences of metaphysics are pseudo-sentences which on logical analysis are proved to be either empty phrases or phrases which violate the rules of syntax. Of the so-called philosophical problems, the only questions which have any meaning are those of the logic of science. To share this view is to substitute logical syntax for philosophy.

Children don't read to find their identity, to free themselves from guilt, to quench the thirst for rebellion or to get rid of alienation. They have no use for psychology... They still believe in God, the family, angels, devils, witches, goblins, logic, clarity, punctuation, and other such obsolete stuff... When a book is boring, they yawn openly. They don't expect their writer to redeem humanity, but leave to adults such childish illusions.

Isaac Bashevis Singer

Living mathematics rests on the fluctuation between the antithesis powers of intuition and logic, the individuality of "grounded" problems and the generality of far-reaching abstractions. We ourselves must prevent the development being forced to only one pole of the life-giving antithesis.

Logic, properly used, does not shackle thought. It gives freedom, and above all, boldness. Illogical thought hesitates to draw conclusions, because it never knows either what it means, or what it assumes, or how far it trusts its own assumptions, or what will be the effect of any modification of assumptions.

Alfred North Whitehead

Mathematics is, as it were, a sensuous logic, and relates to philosophy as do the arts, music, and plastic art to poetry.

Karl Wilhelm Friedrich Schlegel

But logic is not all, one needs one's heart to follow an idea.

Richard Feynman

Logic is like sitting on the bank of a river and deducing its contents from a fish caught in its waters.

Edgar Young Mullins

Logic is a wonderful thing but doesn't always beat actual thought.

Terry Pratchett

When a person does something, it has the man or woman look about it. It drips with humanity. You can follow the logic of it and see the meaning behind it.

Mathematical logic deals not with the truth but only with the game of truth.

Gian-Carlo Rota

But, if logic is the hygiene of the mathematician, it is not his source of food; the great problems furnish the daily bread on which he thrives.