Quotes about doubt
A collection of quotes on the topic of question, questioner, doing, answer.
Best quotes about doubt

“I don't know the question, but sex is definitely the answer.”

“Ignorance never settles a question.”
Source: Speech in the House of Commons (14 May 1866)

“The question is not what you look at, but what you see.”
Variant: It's not what you look at that matters, it's what you see.

“The important thing is not to stop questioning.”
Old Man's Advice to Youth: "Never Lose a Holy Curiosity," http://books.google.com/books?id=dlYEAAAAMBAJ&lpg=PP1&dq=Life%2C%202%20May%201955&pg=PA61#v=onepage&q=Life,%202%20May%201955&f=false LIFE magazine (2 May 1955) statement to William Miller, p. 64.
1950s
Context: The important thing is not to stop questioning. Curiosity has its own reason for existence. One cannot help but be in awe when he contemplates the mysteries of eternity, of life, of the marvelous structure of reality. It is enough if one tries merely to comprehend a little of this mystery each day. Never lose a holy curiosity. … Don't stop to marvel.

“A prudent question is one-half of wisdom.”

“What I assert, deny, question, in the present, I still can.”
Molloy (1951)
Context: What I assert, deny, question, in the present, I still can. But mostly I shall use the various tenses of the past. For mostly I do not know, it is perhaps no longer so, it is too soon to know, I simply do not know, perhaps shall never know.

“It's not only the question, but the way you try to solve it.”
Interview with Research Fellow Maryam Mirzakhani | january 2008
Quotes about doubt

Translation source: Yuzuru Hanyu – World Championships 2021 ‘Day After’ Interview https://axelwithwings.com/2021/03/30/eng-translation-yuzuru-hanyu-world-championships-2021-day-after-interview-210328/ by Axel with Wings, published 28 March 2021. (Retrieved 31 March 2021)
Other quotes, 2021
Original: (ja) なんか限界だなって感じはないです。ただ、この限界だなって思うかもしれない時期をどうやって乗り越えていくか。
Source: Part 1 of the final interview at Worlds 2021 in Stockholm, as quoted in an article https://www.sponichi.co.jp/sports/news/2021/03/28/kiji/20210328s00079000616000c.html by Nippon Sports (Sponichi), published 28 March 2021. (Retrieved 31 March 2021)
Teacher

"The Meaning of Life: The Big Picture", Life Magazine (December 1988)
Interviews

Nobel Peace Prize Lecture (December 10, 2014)

“Think for yourself and question authority.”
Timothy Leary's track on Sound Bites from the Counter Culture (1989)

Diogenes Laërtius, vi. 54
Quoted by Diogenes Laërtius

“Have patience with everything that remains unsolved in your heart.
… live in the question.”
Source: Letters to a Young Poet

“Judge a man by his questions rather than by his answers.”
Il est encore plus facile de juger de l'esprit d'un homme par ses questions que par ses réponses. (It is easier to judge the mind of a man by his questions rather than his answers) — Pierre-Marc-Gaston, duc de Lévis (1764-1830), Maximes et réflexions sur différents sujets de morale et de politique (Paris, 1808): Maxim xviii
Misattributed

Dear Mr. President, featuring the Indigo Girls, written by Pink and Billy Mann
Song lyrics, I'm Not Dead (2006)

This has also appeared in the alternate form: "What we observe is not nature itself, but nature exposed to our method of questioning."
Physics and Philosophy (1958)
Variant: What we observe is not nature itself, but nature exposed to our method of questioning.
Source: Physics and Philosophy: The Revolution in Modern Science

“The scientist is not a person who gives the right answers, he's one who asks the right questions.”

“Why are there beings at all, and why not rather nothing? That is the question.”
Warum ist überhaupt Seiendes und nicht vielmehr Nichts? Das ist die Frage.
What is Metaphysics? (1929), p. 110
Cf. Gottfried Leibniz, De rerum originatione radicali (1697)ː "cur aliquid potius extiterit quam nihil."
Source: Introduction to Metaphysics

From interview with Malavika Sangghvi

To Leon Goldensohn (21 May 1946)
The Nuremberg Interviews (2004)

“These questions replace our original, "Can machines think?"”
Computing Machinery and Intelligence (1950)
Context: "Can machines think?"... The new form of the problem can be described in terms of a game which we call the 'imitation game." It is played with three people, a man (A), a woman (B), and an interrogator (C) who may be of either sex. The interrogator stays in a room apart front the other two. The object of the game for the interrogator is to determine which of the other two is the man and which is the woman. He knows them by labels X and Y, and at the end of the game he says either "X is A and Y is B" or "X is B and Y is A." The interrogator is allowed to put questions to A and B... We now ask the question, "What will happen when a machine takes the part of A in this game?" Will the interrogator decide wrongly as often when the game is played like this as he does when the game is played between a man and a woman? These questions replace our original, "Can machines think?"

"Experiments With Alternate Currents Of High Potential And High Frequency" (February 1892)
Context: Ere many generations pass, our machinery will be driven by a power obtainable at any point of the universe. This idea is not novel. Men have been led to it long ago by instinct or reason; it has been expressed in many ways, and in many places, in the history of old and new. We find it in the delightful myth of Antaeus, who derives power from the earth; we find it among the subtle speculations of one of your splendid mathematicians and in many hints and statements of thinkers of the present time. Throughout space there is energy. Is this energy static or kinetic! If static our hopes are in vain; if kinetic — and this we know it is, for certain — then it is a mere question of time when men will succeed in attaching their machinery to the very wheelwork of nature.

As quoted in "J. Robert Oppenheimer" by L. Barnett, in Life, Vol. 7, No. 9, International Edition (24 October 1949), p. 58; sometimes a partial version (the final sentence) is misattributed to Marcel Proust.
Context: There must be no barriers to freedom of inquiry … There is no place for dogma in science. The scientist is free, and must be free to ask any question, to doubt any assertion, to seek for any evidence, to correct any errors. Our political life is also predicated on openness. We know that the only way to avoid error is to detect it and that the only way to detect it is to be free to inquire. And we know that as long as men are free to ask what they must, free to say what they think, free to think what they will, freedom can never be lost, and science can never regress.

“I never stole in my childhood, so there was no question of apologising to my father.”
Godse referring to Gandhi's autobiographical story, where Gandhi stole a piece of gold from his father's watch and later on apologised to his father
Excerpts from the play Mee Nathuram Godse boltoy

Variant: If there's any message, it is ultimately that it's okay to be different; that it's good to be different, that we should question ourselves before we pass judgment on someone who looks different, behaves different, talks different, is a different color.
Source: A Thousand Mornings

“A wise man can learn more from a foolish question than a fool can learn from a wise answer.”

“I refuse to answer that question on the grounds that I don't know the answer”

“I was never aware of any other option but to question everything.”

Source: Thinking in Pictures: My Life with Autism

Bible Series V: Cain and Abel: The Hostile Brothers
Concepts

Conjectures and Refutations: The Growth of Scientific Knowledge (1963)

The Yoga of Nutrition, Editions Prosveta, 2012 ebook edition, pp. 24 https://books.google.it/books?id=jnoVCwAAQBAJ&pg=PT24-25.

Sur un nouveau genre de calcul, 1826.

Science and Humanism (1951)
Context: I am born into an environment — I know not whence I came nor whither I go nor who I am. This is my situation as yours, every single one of you. The fact that everyone always was in this same situation, and always will be, tells me nothing. Our burning question as to the whence and whither — all we can ourselves observe about it is the present environment. That is why we are eager to find out about it as much as we can. That is science, learning, knowledge; it is the true source of every spiritual endeavour of man. We try to find out as much as we can about the spatial and temporal surroundings of the place in which we find ourselves put by birth…

J. K. Rowling, as quoted in Harry Potter's Bookshelf : The Great Books Behind the Hogwarts Adventures (2009) by John Granger <!-- also partly in Biography Today : Profiles of People of Interest to Young Readers Vol. 17, Issue 1 (2008), p. 142 -->
2000s
Context: I think most of us if you were asked to name a very evil regime would think of Nazi Germany. … I wanted Harry to leave our world and find exactly the same problems in the Wizarding world. So you have to the intent to impose a hierarchy, you have bigotry, and this notion of purity, which is a great fallacy, but it crops up all over the world. People like to think themselves superior and that if they can pride themselves on nothing else, they can pride themselves on perceived purity. … The Potter books in general are a prolonged argument for tolerance, a prolonged plea for an end to bigotry, and I think it's one of the reasons that some people don't like the books, but I think that it's a very healthy message to pass on to younger people that you should question authority and you should not assume that the establishment or the press tells you all of the truth.

“Freedom is the right to question and change the established way of doing things.”
Moscow State University http://www.reagan.utexas.edu/archives/speeches/1988/053188b.htm (31 May 1988)
1980s, Second term of office (1985–1989)
Context: Freedom is the right to question and change the established way of doing things. It is the continuous revolution of the marketplace. It is the understanding that allows to recognize shortcomings and seek solutions.

Designing the Future (2007)

1930s, Die verfluchten Hakenkreuzler. Etwas zum Nachdenken (1932)

Source: Proudhon: What Is Property?

“There are years that ask questions and years that answer.”
Source: Their Eyes Were Watching God (1937), Ch. 3, p. 21.

“The power to question is the basis of all human progress.”

Source: A Brief History of Time (1988), Ch. 12
Context: Even if there is only one possible unified theory, it is just a set of rules and equations. What is it that breathes fire into the equations and makes a universe for them to describe? The usual approach of science of constructing a mathematical model cannot answer the questions of why there should be a universe for the model to describe. Why does the universe go to all the bother of existing?
Source: The Chronicles of Prydain (1964–1968), Book I: The Book of Three (1964), Chapter 1
Context: "Why?" Dallben interrupted. "In some cases," he said, "we learn more by looking for the answer to a question and not finding it than we do from learning the answer itself."

“The most basic question is not what is best, but who shall decide what is best.”

“Sometimes the questions are complicated and the answers are simple.”
Variant: Sometimes the questions are complicated and the answers are simple.

“What's dry?' 'Good question. Next question!”

“O my body, make of me always a man who questions!”
Variant: Oh my body, make of me a man who always questions!
Source: Black Skin, White Masks

Source: Contributions to Modern Economics (1978), Chapter 7, Marx, Marshall and Keynes, p. 75

“You people would convict a grilled cheese sandwich of murder and the people wouldn’t question it.”

“The question isn't who is going to let me; it's who is going to stop me.”

Attributed in American Quotations (1992) by Gorton Carruth and Eugene H. Ehrlich, p. 149
1990s
"Moral Beliefs"

“There are two sides to every question.”
As quoted in Lives of Eminent Philosophers, by Diogenes Laërtius, Book IX, Sec. 51

"The Problem of Ego Identity" (1956), published in Journal of the American Psychoanalytic Association, 4:56-121

On temptation - "'ATTRIBUTING THE SATELLITES SUCCESS TO ME IS BLASPHEMY' – T.B. JOSHUA" http://www.modernghana.com/print/247180/1/attributing-the-satellites-success-to-me-is-blasph.html Modern Ghana (November 4 2009)

From interview with Rajeev Masand

"The Popular and the Realistic" (written 1938, published 1958), as translated in Brecht on Theatre (1964) edited and translated by John Willett.
My Twisted World (2014), 19-22, UC Santa Barbara, Building to Violence

"As I Please," Tribune (12 May 1944)<sup> http://alexpeak.com/twr/orwell/quotes/</sup>
"As I Please" (1943–1947)

Cited in: Michael J. Gelb (1996) Thinking for a change: discovering the power to create, communicate and lead. p. 96

Addresses and Essays on Vegetarianism (1912); quoted in Awe for the Tiger, Love for the Lamb by Rod Preece (Routledge, 2002), p. 344 https://books.google.it/books?id=Mf6TAgAAQBAJ&pg=PA344.