# Quotes about logic

- Quotes: 51
- Authors: 29
- Broader topic: [Quotes about thinking](https://www.leafyquotes.com/topics/thinking.md)
- Topic page: https://www.leafyquotes.com/topics/logic
- JSON version (same data): https://www.leafyquotes.com/topics/logic.json

## Quotes

> Logic ignores the Almost, just as the sun ignores the candle.

[Victor Hugo](https://www.leafyquotes.com/victor-hugo.md) · [Les Miserables](https://www.leafyquotes.com/victor-hugo/les-miserables.md) · p. 699 — [Quote page](https://www.leafyquotes.com/victor-hugo/les-miserables/logic-ignores-the.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> It is by logic that we prove, but by intuition that we discover. To know how to criticize is good, to know how to create is better.

[Henri Poincaré](https://www.leafyquotes.com/henri-poincare.md) · [Science and Method](https://www.leafyquotes.com/henri-poincare/science-and-method.md) · p. 129 — [Quote page](https://www.leafyquotes.com/henri-poincare/science-and-method/it-is-by-logic.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md), [intuition](https://www.leafyquotes.com/topics/intuition.md)

> Logic teaches us that on such and such a road we are sure of not meeting an obstacle; it does not tell us which is the road that leads to the desired end. For this, it is necessary to see the end from afar, and the faculty which teaches us to see is intuition. Without it, the geometrician would be like a writer well up in grammar but destitute of ideas.

[Henri Poincaré](https://www.leafyquotes.com/henri-poincare.md) · [Science and Method](https://www.leafyquotes.com/henri-poincare/science-and-method.md) · p. 130 — [Quote page](https://www.leafyquotes.com/henri-poincare/science-and-method/logic-teaches-us-that.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md), [intuition](https://www.leafyquotes.com/topics/intuition.md)

> All that was necessary was to use one’s imagination to see how it might have happened, and then check the evidence to see if it did happen that way. The final step is to check the evidence to make sure it could not have happened any other way.

[Randall Garrett](https://www.leafyquotes.com/randall-garrett.md) · [Lord Darcy](https://www.leafyquotes.com/randall-garrett/lord-darcy.md) · p. 167 — [Quote page](https://www.leafyquotes.com/randall-garrett/lord-darcy/all-that-was.md)

Topics: [imagination](https://www.leafyquotes.com/topics/imagination.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> But in this age, logic was a flame that must be frequently starved of fuel.

[Matt Hughes](https://www.leafyquotes.com/matt-hughes.md) · [The Spiral Labyrinth](https://www.leafyquotes.com/matt-hughes/the-spiral-labyrinth.md) · p. 84 — [Quote page](https://www.leafyquotes.com/matt-hughes/the-spiral-labyrinth/but-in-this.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> “It has never happened!” cannot be construed to mean, “It can never happen!”—as well say, “Because I have never broken my leg, my leg is unbreakable,” or “Because I’ve never died, I am immortal.”

[George R. Stewart](https://www.leafyquotes.com/george-r-stewart.md) · [Earth Abides](https://www.leafyquotes.com/george-r-stewart/earth-abides.md) · p. 8 — [Quote page](https://www.leafyquotes.com/george-r-stewart/earth-abides/it-has-never.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> There were so many possible logical holes in that statement that Irene could have used it as a tea-strainer.

[Genevieve Cogman](https://www.leafyquotes.com/genevieve-cogman.md) · [The Burning Page](https://www.leafyquotes.com/genevieve-cogman/the-burning-page.md) · p. 64 — [Quote page](https://www.leafyquotes.com/genevieve-cogman/the-burning-page/there-were-so-many.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Humans were inexplicable only if you assumed that they were logical.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Starfire](https://www.leafyquotes.com/charles-sheffield/starfire.md) · p. 70 — [Quote page](https://www.leafyquotes.com/charles-sheffield/starfire/humans-were-inexplicable.md)

Topics: [human nature](https://www.leafyquotes.com/topics/human-nature.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Logic was good, but too much logical analysis inhibited action. Darya had heard it seriously suggested that the original human cladeworld, Earth, had degenerated to an ineffectual backwater of a planet because computer trade-off analysis had increasingly been used as the basis for decision making. On purely logical grounds, no one would ever explore, invent, rejoice, sing, strive, fall in love, or take physical and psychological risks of any kind. Better to stay in bed in the morning; it was much safer.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Convergence](https://www.leafyquotes.com/charles-sheffield/convergence.md) · p. 481 — [Quote page](https://www.leafyquotes.com/charles-sheffield/convergence/logic-was-good.md)

Topics: [risk](https://www.leafyquotes.com/topics/risk.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Darya had a few moments of wild hope before logic intruded.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Transcendence](https://www.leafyquotes.com/charles-sheffield/transcendence.md) · p. 194 — [Quote page](https://www.leafyquotes.com/charles-sheffield/transcendence/darya-had-a-few.md)

Topics: [hope](https://www.leafyquotes.com/topics/hope.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Kallik’s explanation was neat, logical, and complete. Like most such explanations, it was, in Hans Rebka’s view, almost certainly wrong. That was not the way the real world operated.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Transcendence](https://www.leafyquotes.com/charles-sheffield/transcendence.md) · p. 212 — [Quote page](https://www.leafyquotes.com/charles-sheffield/transcendence/kalliks-explanation-was.md)

Topics: [reality](https://www.leafyquotes.com/topics/reality.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Darya found the logic of her thought processes so compelling that it never occurred to her that others might have a different reaction. But they did.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Transcendence](https://www.leafyquotes.com/charles-sheffield/transcendence.md) · p. 122 — [Quote page](https://www.leafyquotes.com/charles-sheffield/transcendence/darya-found-the.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> Darya stood up, heard her voice rising, and knew she was doing what she insisted what a scientist should never do: allowing passion and the defense of personal theories to interfere with logical analysis.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Transcendence](https://www.leafyquotes.com/charles-sheffield/transcendence.md) · p. 45 — [Quote page](https://www.leafyquotes.com/charles-sheffield/transcendence/darya-stood-up-heard.md)

Topics: [science](https://www.leafyquotes.com/topics/science.md), [passion](https://www.leafyquotes.com/topics/passion.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> But no one, no matter how intelligent, could make good inferences from bad data.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Transcendence](https://www.leafyquotes.com/charles-sheffield/transcendence.md) · p. 126 — [Quote page](https://www.leafyquotes.com/charles-sheffield/transcendence/but-no-one.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md), [information](https://www.leafyquotes.com/topics/information.md)

> That’s what logic says. But I say, phooey, who wants logic? Not you, and not me. We want results.

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Summertide](https://www.leafyquotes.com/charles-sheffield/summertide.md) · p. 150 — [Quote page](https://www.leafyquotes.com/charles-sheffield/summertide/thats-what-logic.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> “It sounds reasonable to me.”
>
> “Reasonable, but not true. Big difference.”

[Charles Sheffield](https://www.leafyquotes.com/charles-sheffield.md) · [Proteus in the Underworld](https://www.leafyquotes.com/charles-sheffield/proteus-in-the-underworld.md) · p. 251 — [Quote page](https://www.leafyquotes.com/charles-sheffield/proteus-in-the-underworld/it-sounds-reasonable.md)

Topics: [truth](https://www.leafyquotes.com/topics/truth.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> A difference which makes no difference is no difference.

[Steven R. Boyett](https://www.leafyquotes.com/steven-r-boyett.md) · [Ariel](https://www.leafyquotes.com/steven-r-boyett/ariel.md) · p. 47 — [Quote page](https://www.leafyquotes.com/steven-r-boyett/ariel/a-difference-which.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> Correlation and causation are two quite different words, and the innumerate are more prone to mistake them than most.

[John Allen Paulos](https://www.leafyquotes.com/john-allen-paulos.md) · [Innumeracy](https://www.leafyquotes.com/john-allen-paulos/innumeracy.md) · p. 159 — [Quote page](https://www.leafyquotes.com/john-allen-paulos/innumeracy/correlation-and-causation.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md), [statistics](https://www.leafyquotes.com/topics/statistics.md)

> That logic, as a science, is susceptible of very wide applications is admitted; but it is equally certain that its ultimate forms and processes are mathematical.

[George Boole](https://www.leafyquotes.com/george-boole.md) · [An Investigation of the Laws of Thought](https://www.leafyquotes.com/george-boole/an-investigation-of-the-laws-of-thought.md) · p. 12 — [Quote page](https://www.leafyquotes.com/george-boole/an-investigation-of-the-laws-of-thought/that-logic-as-a-science.md)

Topics: [mathematics](https://www.leafyquotes.com/topics/mathematics.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> There is not only a close analogy between the operations of the mind in general reasoning and its operations in the particular science of Algebra, but there is to a considerable extent an exact agreement in the laws by which the two classes of operations are conducted.

[George Boole](https://www.leafyquotes.com/george-boole.md) · [An Investigation of the Laws of Thought](https://www.leafyquotes.com/george-boole/an-investigation-of-the-laws-of-thought.md) · p. 6 — [Quote page](https://www.leafyquotes.com/george-boole/an-investigation-of-the-laws-of-thought/there-is-not.md)

Topics: [mathematics](https://www.leafyquotes.com/topics/mathematics.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> LOGIC   The principle governing human intellection. Its nature may be deduced from examining the following propositions, both of which are held by human beings to be true and often by the same people: “I can’t so you musn’t,” and “I can but you musn’t.”

[John Brunner](https://www.leafyquotes.com/john-brunner.md) · [Stand On Zanzibar](https://www.leafyquotes.com/john-brunner/stand-on-zanzibar.md) — [Quote page](https://www.leafyquotes.com/john-brunner/stand-on-zanzibar/logic-the-principle.md)

Topics: [hypocrisy](https://www.leafyquotes.com/topics/hypocrisy.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Of course I've contradicted myself. I always do. Only cretins and logicians don't contradict themselves. And in their consistency, they contradict life.

[Tom Robbins](https://www.leafyquotes.com/tom-robbins.md) · [Even Cowgirls Get the Blues](https://www.leafyquotes.com/tom-robbins/even-cowgirls-get-the-blues.md) · p. 268 — [Quote page](https://www.leafyquotes.com/tom-robbins/even-cowgirls-get-the-blues/of-course-ive.md)

Topics: [paradox](https://www.leafyquotes.com/topics/paradox.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> The rejection process is incorporated in the concept of the negative. The negative is a judgement device. It is the means whereby one rejects certain arrangements of information. The negative is used to carry out judgement and to indicate rejection. The concept of the negative is crystallized into a definite language tool. This language tool consists of the words no and not. Once one learns the function and use of these words one has learned how to use logical thinking. The whole concept of logical thinking is concentrated in the use of this language tool. Logic could be said to be the management of NO.

[Edward de Bono](https://www.leafyquotes.com/edward-de-bono.md) · [Lateral Thinking](https://www.leafyquotes.com/edward-de-bono/lateral-thinking.md) · p. 159 — [Quote page](https://www.leafyquotes.com/edward-de-bono/lateral-thinking/the-rejection-process.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> The concept of logical thinking is selection and this is brought about by the processes of acceptance and rejection. Rejection is the basis of logical thinking.

[Edward de Bono](https://www.leafyquotes.com/edward-de-bono.md) · [Lateral Thinking](https://www.leafyquotes.com/edward-de-bono/lateral-thinking.md) · p. 159 — [Quote page](https://www.leafyquotes.com/edward-de-bono/lateral-thinking/the-concept-of-logical.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> Utinam logica falsa tuam philosophiam totam suffodiant!
>
> May faulty logic undermine your entire philosophy!

[Henry Beard](https://www.leafyquotes.com/henry-beard.md) · [Latin for All Occasions](https://www.leafyquotes.com/henry-beard/latin-for-all-occasions.md) — [Quote page](https://www.leafyquotes.com/henry-beard/latin-for-all-occasions/utinam-logica-falsa.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> In short, Mort was one of those people who are more dangerous than a bag full of rattlesnakes. He was determined to discover the underlying logic behind the universe... which was going to be hard, because there wasn't one.

[Terry Pratchett](https://www.leafyquotes.com/terry-pratchett.md) · [Mort](https://www.leafyquotes.com/terry-pratchett/mort.md) — [Quote page](https://www.leafyquotes.com/terry-pratchett/mort/in-short-mort.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [the universe](https://www.leafyquotes.com/topics/the-universe.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> It was all very well going on about pure logic and how the universe was ruled by logic and the harmony of numbers, but the plain fact of the matter was that the Disc was manifestly traversing space on the back of a giant turtle and the gods had a habit of going round to atheists' houses and smashing their windows.

[Terry Pratchett](https://www.leafyquotes.com/terry-pratchett.md) · [The Colour of Magic](https://www.leafyquotes.com/terry-pratchett/the-colour-of-magic.md) — [Quote page](https://www.leafyquotes.com/terry-pratchett/the-colour-of-magic/it-was-all.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [god](https://www.leafyquotes.com/topics/god.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> It is important to note that the most brilliant discoveries have not relied on a formal knowledge of logic. Instead, their discoverers have had an acute inner logic that generates ideas with the same unstudied unconsciousness that allowed Jourdain to create prose.

[Santiago Ramon Y Cajal](https://www.leafyquotes.com/santiago-ramon-y-cajal.md) · [Advice for a Young Investigator](https://www.leafyquotes.com/santiago-ramon-y-cajal/advice-for-a-young-investigator.md) — [Quote page](https://www.leafyquotes.com/santiago-ramon-y-cajal/advice-for-a-young-investigator/it-is-important.md)

Topics: [science](https://www.leafyquotes.com/topics/science.md), [logic](https://www.leafyquotes.com/topics/logic.md), [intuition](https://www.leafyquotes.com/topics/intuition.md)

> You seem to be using some sort of logical system where when you get near any explanation, you say: “By definition my problem is insoluble. Now that explanation over there would solve it. But since I’ve defined my problem as insoluble, then by definition that solution doesn’t apply.”

[Samuel R. Delany](https://www.leafyquotes.com/samuel-r-delany.md) · [Triton](https://www.leafyquotes.com/samuel-r-delany/triton.md) · p. 123 — [Quote page](https://www.leafyquotes.com/samuel-r-delany/triton/you-seem-to-be-using.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md), [problems](https://www.leafyquotes.com/topics/problems.md)

> When you want to enjoy something, you must never let logic get too much in the way.

[Jerry Seinfeld](https://www.leafyquotes.com/jerry-seinfeld.md) · [Seinlanguage](https://www.leafyquotes.com/jerry-seinfeld/seinlanguage.md) — [Quote page](https://www.leafyquotes.com/jerry-seinfeld/seinlanguage/when-you-want.md)

Topics: [pleasure](https://www.leafyquotes.com/topics/pleasure.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> It is known that there are an infinite number of worlds, simply because there is an infinite amount of space for them to be in. However, not every one of them is inhabited. Therefore, there must be a finite number of inhabited worlds. Any finite number divided by infinity is as near to nothing as makes no odds, so the average population of all the planets in the Universe can be said to be zero. From this it follows that the population of the whole Universe is also zero, and that any people you may meet from time to time are merely the products of a deranged imagination.

[Douglas Adams](https://www.leafyquotes.com/douglas-adams.md) · [The Restaurant at the End of the Universe](https://www.leafyquotes.com/douglas-adams/the-restaurant-at-the-end-of-the-universe.md) — [Quote page](https://www.leafyquotes.com/douglas-adams/the-restaurant-at-the-end-of-the-universe/it-is-known.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [the universe](https://www.leafyquotes.com/topics/the-universe.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> "The Babel fish," said The Hitchhiker's Guide to the Galaxy quietly, "is small, yellow and leech-like, and probably the oddest thing in the Universe. It feeds on brainwave energy received not from its own carrier but from those around it. It absorbs all unconscious mental frequencies from this brainwave energy to nourish itself with. It then excretes into the mind of its carrier a telepathic matrix formed by combining the conscious thought frequencies with nerve signals picked up from the speech centres of the brain which has supplied them. The practical upshot of all this is that if you stick a Babel fish in your ear you can instantly understand anything in any form of language. The speech patterns you actually hear decode the brainwave matrix which has been fed into your mind by your Babel fish.
>
> "Now it is such a bizarrely improbable coincidence that anything so mindbogglingly useful could have evolved purely by chance that some thinkers have chosen to see it as the final and clinching proof of the non-existence of God.
>
> "The argument goes something like this: 'I refuse to prove that I exist,' says God, 'for proof denies faith, and without faith I am nothing.'
>
> "'But,' says Man, 'the Babel fish is a dead giveaway, isn't it? It could not have evolved by chance. It proves you exist, and so therefore, by your own arguments, you don't. QED.'
>
> "'Oh dear,' says God, 'I hadn't thought of that,' and promptly vanishes in a puff of logic.
>
> "'Oh, that was easy,' says Man, and for an encore goes on to prove that black is white and gets himself killed on the next zebra crossing.
>
> "Most leading theologians claim that this argument is a load of dingo's kidneys, but that didn't stop Oolon Colluphid making a small fortune when he used it as the central theme of his bestselling book, Well That about Wraps It Up for God.
>
> "Meanwhile, the poor Babel fish, by effectively removing all barriers to communication between different races and cultures, has caused more and bloodier wars than anything else in the history of creation."

[Douglas Adams](https://www.leafyquotes.com/douglas-adams.md) · [The Hitchhiker's Guide To The Galaxy: Primary Phase](https://www.leafyquotes.com/douglas-adams/the-hitchhikers-guide-to-the-galaxy-primary-phase.md) — [Quote page](https://www.leafyquotes.com/douglas-adams/the-hitchhikers-guide-to-the-galaxy-primary-phase/the-babel-fish.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [god](https://www.leafyquotes.com/topics/god.md), [faith](https://www.leafyquotes.com/topics/faith.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> "When I disagree with a rational man, I let reality be our final arbiter; if I am right, he will learn; if I am wrong, I will; one of us will win, but both will profit."

[Ayn Rand](https://www.leafyquotes.com/ayn-rand.md) · [Atlas Shrugged](https://www.leafyquotes.com/ayn-rand/atlas-shrugged.md) · p. 1023 — [Quote page](https://www.leafyquotes.com/ayn-rand/atlas-shrugged/when-i-disagree.md)

Topics: [reason](https://www.leafyquotes.com/topics/reason.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> "To arrive at a contradiction is to confess an error in one's thinking; to maintain a contradiction is to abdicate one's mind and to evict oneself from the realm of reality."

[Ayn Rand](https://www.leafyquotes.com/ayn-rand.md) · [Atlas Shrugged](https://www.leafyquotes.com/ayn-rand/atlas-shrugged.md) · p. 1016 — [Quote page](https://www.leafyquotes.com/ayn-rand/atlas-shrugged/to-arrive-at-a-contradiction.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> "Contradictions do not exist. Whenever you think you are facing a contradiction, check your premises. You will find that one of them is wrong."

[Ayn Rand](https://www.leafyquotes.com/ayn-rand.md) · [Atlas Shrugged](https://www.leafyquotes.com/ayn-rand/atlas-shrugged.md) · p. 199 — [Quote page](https://www.leafyquotes.com/ayn-rand/atlas-shrugged/contradictions-do-not.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> "If there's a buzzing-noise, somebody's making a buzzing-noise, and the only reason for making a buzzing-noise that I know of is because you're a bee."
>
> Then he thought another long time, and said: "And the only reason for being a bee that I know of is making honey."
>
> And then he got up, and said: "And the only reason for making honey is so I can eat it." So he began to climb the tree.

[A.A. Milne](https://www.leafyquotes.com/aa-milne.md) · [Winnie the Pooh](https://www.leafyquotes.com/aa-milne/winnie-the-pooh.md) — [Quote page](https://www.leafyquotes.com/aa-milne/winnie-the-pooh/if-theres-a-buzzing-noise.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Logic works, metaphysics contemplates.

[Joseph Joubert](https://www.leafyquotes.com/joseph-joubert.md) · [The Notebooks of Joseph Joubert](https://www.leafyquotes.com/joseph-joubert/the-notebooks-of-joseph-joubert.md) — [Quote page](https://www.leafyquotes.com/joseph-joubert/the-notebooks-of-joseph-joubert/logic-works-metaphysics.md)

Topics: [philosophy](https://www.leafyquotes.com/topics/philosophy.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Then I was in love with herself after all, said Diana, making one of those feminine leaps in logic that leave men breathless.

[Robertson Davies](https://www.leafyquotes.com/robertson-davies.md) · [The Deptford Trilogy](https://www.leafyquotes.com/robertson-davies/the-deptford-trilogy.md) — [Quote page](https://www.leafyquotes.com/robertson-davies/the-deptford-trilogy/then-i-was.md)

Topics: [humor](https://www.leafyquotes.com/topics/humor.md), [women](https://www.leafyquotes.com/topics/women.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> There are only two means by which men can deal with one another: guns or logic. Force or persuasion. Those who know that they cannot win by means of logic, have always resorted to guns.

[Ayn Rand](https://www.leafyquotes.com/ayn-rand.md) · [Philosophy](https://www.leafyquotes.com/ayn-rand/philosophy.md) — [Quote page](https://www.leafyquotes.com/ayn-rand/philosophy/there-are-only.md)

Topics: [violence](https://www.leafyquotes.com/topics/violence.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> It is impossible as I state it, and therefore I must in some respect have stated it wrong.

[Arthur Conan Doyle](https://www.leafyquotes.com/arthur-conan-doyle.md) · [The Return of Sherlock Holmes](https://www.leafyquotes.com/arthur-conan-doyle/the-return-of-sherlock-holmes.md) · p. 550 — [Quote page](https://www.leafyquotes.com/arthur-conan-doyle/the-return-of-sherlock-holmes/it-is-impossible.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> It is an old maxim of mine that when you have excluded the impossible, whatever remains, however improbable, must be the truth.

[Arthur Conan Doyle](https://www.leafyquotes.com/arthur-conan-doyle.md) · [The Adventures of Sherlock Holmes](https://www.leafyquotes.com/arthur-conan-doyle/the-adventures-of-sherlock-holmes.md) · p. 315 — [Quote page](https://www.leafyquotes.com/arthur-conan-doyle/the-adventures-of-sherlock-holmes/it-is-an-old.md)

Topics: [truth](https://www.leafyquotes.com/topics/truth.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> I have already explained to you that what is out of the common is usually a guide rather than a hindrance. In solving a problem of this sort, the grand thing is to be able to reason backward. That is a very useful accomplishment, and a very easy one, but people do not practice it much. In the everyday affairs of life it is more useful to reason forward, and so the other comes to be neglected. There are fifty who can reason synthetically for one who can reason analytically.

[Arthur Conan Doyle](https://www.leafyquotes.com/arthur-conan-doyle.md) · [A Study in Scarlet](https://www.leafyquotes.com/arthur-conan-doyle/a-study-in-scarlet.md) · p. 83 — [Quote page](https://www.leafyquotes.com/arthur-conan-doyle/a-study-in-scarlet/i-have-already.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> Mathematics is not just a language. Mathematics is a language plus reasoning. It's like a language plus logic. Mathematics is a tool for reasoning. It's, in fact, a big collection of the results of some person's careful thought and reasoning. By mathematics, it is possible to connect one statement to another.

[Richard P. Feynman](https://www.leafyquotes.com/richard-p-feynman.md) · [The Character of Physical Law](https://www.leafyquotes.com/richard-p-feynman/the-character-of-physical-law.md) — [Quote page](https://www.leafyquotes.com/richard-p-feynman/the-character-of-physical-law/mathematics-is-not.md)

Topics: [mathematics](https://www.leafyquotes.com/topics/mathematics.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> It is impossible, by the way, when picking one example of anything, to avoid picking one which is atypical in some sense.

[Richard P. Feynman](https://www.leafyquotes.com/richard-p-feynman.md) · [The Character of Physical Law](https://www.leafyquotes.com/richard-p-feynman/the-character-of-physical-law.md) · p. 27 — [Quote page](https://www.leafyquotes.com/richard-p-feynman/the-character-of-physical-law/it-is-impossible.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md)

> Deep in the human unconscious is a pervasive need for a logical universe that makes sense. But the real universe is always one step beyond logic.

[Frank Herbert](https://www.leafyquotes.com/frank-herbert.md) · [Dune](https://www.leafyquotes.com/frank-herbert/dune.md) — [Quote page](https://www.leafyquotes.com/frank-herbert/dune/deep-in-the.md)

Topics: [the universe](https://www.leafyquotes.com/topics/the-universe.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Anything outside yourself, this you can see and apply your logic to it. But it's a human trait that when we encounter personal problems, these things most deeply personal are the most difficult to bring out for our logic to scan. We tend to flounder around, blaming everything but the actual, deep-seated thing that's really chewing on us.

[Frank Herbert](https://www.leafyquotes.com/frank-herbert.md) · [Dune](https://www.leafyquotes.com/frank-herbert/dune.md) — [Quote page](https://www.leafyquotes.com/frank-herbert/dune/anything-outside-yourself.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md), [problems](https://www.leafyquotes.com/topics/problems.md)

> Dialectic, which is the parent of logic, came itself from rhetoric. Rhetoric is in turn the child of the myths and poetry of ancient Greece. That is so historically, and that is so by any application of common sense. The poetry and the myths are the response of a prehistoric people to the universe around them made on the basis of Quality. It is Quality, not dialectic, which is the generator of everything we know.

[Robert M. Pirsig](https://www.leafyquotes.com/robert-m-pirsig.md) · [Zen and the Art of Motorcycle Maintenance](https://www.leafyquotes.com/robert-m-pirsig/zen-and-the-art-of-motorcycle-maintenance.md) — [Quote page](https://www.leafyquotes.com/robert-m-pirsig/zen-and-the-art-of-motorcycle-maintenance/dialectic-which-is-the.md)

Topics: [logic](https://www.leafyquotes.com/topics/logic.md), [mythology](https://www.leafyquotes.com/topics/mythology.md), [quality](https://www.leafyquotes.com/topics/quality.md)

> Ether is, in effect, a merely hypothetical entity, valuable only in so far as it explains that which by means of it we endeavor to explain — light, electricity, or universal gravitation — and only so far as these facts cannot be explained in any other way. In like manner the idea of God is also an hypothesis, valuable only in so far as it enables us to explain that which by means of it we endeavor to explain — the essence and existence of the Universe — and only so long as these cannot be explained in any other way. And since in reality we explain the Universe neither better nor worse with this idea than without it, the idea of God, the supreme petitio principii, is valueless.

[Miguel de Unamuno](https://www.leafyquotes.com/miguel-de-unamuno.md) · [Tragic Sense of Life](https://www.leafyquotes.com/miguel-de-unamuno/tragic-sense-of-life.md) — [Quote page](https://www.leafyquotes.com/miguel-de-unamuno/tragic-sense-of-life/ether-is-in-effect.md)

Topics: [god](https://www.leafyquotes.com/topics/god.md), [logic](https://www.leafyquotes.com/topics/logic.md), [atheism](https://www.leafyquotes.com/topics/atheism.md)

> A terrible thing is intelligence. It tends to death as memory tends to stability. The living, the absolutely unstable, the absolutely individual, is strictly unintelligible. Logic tends to reduce everything to identities and genera, to each representation having no more than one self-same content in whatever place, time or relation it may occur to us. And there is nothing that remains for two successive moments of its existence. My idea of God is different each time that I conceive it. Identity, which is death, is the goal of the intellect. The mind seeks what is dead, for what is living escapes it; it seeks to congeal the flowing stream in blocks of ice; it seeks to arrest it. In order to analyze a body it is necessary to extenuate or destroy it. In order to understand anything it is necessary to kill it, to lay it out rigid in the mind.

[Miguel de Unamuno](https://www.leafyquotes.com/miguel-de-unamuno.md) · [Tragic Sense of Life](https://www.leafyquotes.com/miguel-de-unamuno/tragic-sense-of-life.md) — [Quote page](https://www.leafyquotes.com/miguel-de-unamuno/tragic-sense-of-life/a-terrible-thing.md)

Topics: [death](https://www.leafyquotes.com/topics/death.md), [intelligence](https://www.leafyquotes.com/topics/intelligence.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> The "Strange Loop" phenomenon occurs whenever, by moving upwards (or downwards) through levels of some hierarchial system, we unexpectedly find ourselves right back where we started.

[Douglas R. Hofstadter](https://www.leafyquotes.com/douglas-r-hofstadter.md) · [Godel, Escher, Bach](https://www.leafyquotes.com/douglas-r-hofstadter/godel-escher-bach.md) — [Quote page](https://www.leafyquotes.com/douglas-r-hofstadter/godel-escher-bach/the-strange-loop.md)

Topics: [paradox](https://www.leafyquotes.com/topics/paradox.md), [logic](https://www.leafyquotes.com/topics/logic.md)

> Below Every Tangled Hierarchy Lies An Inviolate Level

[Douglas R. Hofstadter](https://www.leafyquotes.com/douglas-r-hofstadter.md) · [Godel, Escher, Bach](https://www.leafyquotes.com/douglas-r-hofstadter/godel-escher-bach.md) — [Quote page](https://www.leafyquotes.com/douglas-r-hofstadter/godel-escher-bach/below-every-tangled.md)

Topics: [mathematics](https://www.leafyquotes.com/topics/mathematics.md), [logic](https://www.leafyquotes.com/topics/logic.md)