WIST Quotations

Moliere -- Don Juan [Dom Juan], Act 3, sc. 1 (1665) [tr. Wilbur (2001)]

Dave — Thu, 06 Nov 2025 23:05:57 +0000

SGANARELLE: But one has to believe in something; what is it that you believe? […]

DON JUAN: I believe that two and two are four, Sganarelle, and that four and four are eight.

[SGANARELLE: Mais encore faut-il croire en quelque chose dans le monde : qu’est-ce donc que vous croyez? […]

DON JUAN: Je crois que deux et deux sont quatre, Sganarelle, et que quatre et quatre sont huit.]

Molière (1622–1673) French playwright, actor [stage name for Jean-Baptiste Poquelin]
Don Juan [Dom Juan], Act 3, sc. 1 (1665) [tr. Wilbur (2001)]
(Source)

This passage, where belief in folk spirits and bogeymen (or, alternately, math) is conflated with religious belief, was dropped from later performances, and is sometimes not included in text versions of the play (e.g., Clitandre (1672)).

(Source (French)). Other translations:

SGAN: People must believe something in this world. What do you believe? [...]
D JU: I believe that two and two are four, Sganarelle, and that twice four are eight.
[tr. Van Laun (1876)]

SGAN: One must believe in something here below. What do you believe in? [...]
JU: Well, I believe that two and two make four, Sganarelle, and that four and four make eight.
[tr. Wall (1879)]

SGAN: Now just tell me (for one must believe something) in what do you believe? [...]
D. JUAN: I believe two and two make four, Sganarelle, and that four and four are eight.
[tr. Waller (1904)]

SGANARELLE: But at least a man must believe in something here below. Now what do you believe in? [...]
DON JUAN: I believe that two and two make four, Sganarelle, and that twice four is eight.
[tr. Page (1908)]

SGANARELLE: A person must have faith in something. What do you believe? [...]
DON JUAN: I believe, Sganarelle, that two and two are four and four and four are eight.
[tr. Bermel (1987)]

Watterson, Bill -- Calvin and Hobbes (1993-06-01)

Dave — Tue, 28 Oct 2025 23:10:05 +0000

CALVIN: Miss Wormwood, I have a question about this math lesson.

TEACHER: Yes?

CALVIN: Given that, sooner or later, we’re all just going to die, what’s the point of learning about integers?

TEACHER: Turn to page 83, class.

CALVIN: (sulking) Nobody likes us “big picture” people.

Bill Watterson (b. 1958) American cartoonist
Calvin and Hobbes (1993-06-01)
(Source)

Von Neumann, John -- Speech, Association for Computing Machinery inaugural conference, Columbia University, New York (15 Sep 1947)

Dave — Tue, 15 Jun 2021 14:41:55 +0000

If people do not believe that mathematics is simple, it is only because they do not realize how complicated life is.

John von Neumann (1903–1957) Hungarian-American mathematician, physicist, inventor, polymath [János "Johann" Lajos Neumann]
Speech, Association for Computing Machinery inaugural conference, Columbia University, New York (15 Sep 1947)
(Source)

Von Neumann insisted that ENIAC's command language could encompass all mathematics, given how only a thousand words could handle most needs of life, and mathematics was, he insisted, simpler than life. When the audience laughed, he replied with this comment. Quoted in Franz L. Alt, "Archaeology of computers: Reminiscences, 1945-1947," Communications of the ACM, Vol 15, #7 (Jul 1972).

Von Neumann, John -- “The Role of Mathematics in the Sciences and in Society,” Speech, Princeton (1954)

Dave — Tue, 25 May 2021 14:20:55 +0000

A large part of mathematics which becomes useful developed with absolutely no desire to be useful, and in a situation where nobody could possibly know in what area it would become useful; and there were no general indications that it ever would be so. By and large it is uniformly true in mathematics that there is a time lapse between a mathematical discovery and the moment when it is useful; and that this lapse of time can be anything from thirty to a hundred years, in some cases even more; and that the whole system seems to function without any direction, without any reference to usefulness, and without any desire to do things which are useful.

John von Neumann (1903–1957) Hungarian-American mathematician, physicist, inventor, polymath [János "Johann" Lajos Neumann]
“The Role of Mathematics in the Sciences and in Society,” Speech, Princeton (1954)
(Source)

Stewart, Ian -- Does God Play Dice? (1989)

Dave — Wed, 20 Jan 2021 17:29:30 +0000

If a man were to leap off the Eiffel Tower, mathematics could predict how long it would take him to hit the ground, but not why he chose to jump in the first place.

Ian Stewart b. 1945) English mathematician, author
Does God Play Dice? (1989)

Von Neumann, John -- (Attributed)

Dave — Wed, 18 Nov 2020 01:47:44 +0000

In mathematics, you don’t understand things, you just get used to them.

John von Neumann (1903–1957) Hungarian-American mathematician, physicist, inventor, polymath [János "Johann" Lajos Neumann]
(Attributed)

The primary source for this comes from Gary Zukav, The Dancing Wu Li Masters: An Overview of the New Physics (1979), in a footnote on p. 208, related to von Neumann's time working on the H-bomb.

Dr. Felix Smith, Head of Molecular Physics, Stanford Research Institute, once related to me the true story of a physicist friend who worked at Los Alamos after World War II. Seeking help on a difficult problem, he went to the great Hungarian mathematician, John von Neumann, who was at Los Alamos as a consultant.

"Simple," said von Neumann. "The can be solved by using the method of characteristics."

After the explanation, the physicist said, "I'm afraid I don't understand the method of characteristics."

"Young man," said von Neumann, "in mathematics you don't understand things, you just get used to them."

David Wells offers a variant in The Penguin Book of Curious and Interesting Mathematics (1997):

Van Neumann had just about ended his lecture when a student stood up and in a vaguely abashed tone said he hadn't understood the final argument. Von Neumann answered: "Young man, in mathematics you don't understand things. You just get used to them.

Variant: "Don't worry, young man: in mathematics, none of us really understands any idea -- we just get used to them."

Kepler, Johannes -- The Harmonies of the World [Harmonices Mundi], Book 4, ch. 1 (1618)

Dave — Thu, 12 Feb 2015 14:38:55 +0000

Since geometry is co-eternal with the divine mind before the birth of things, God himself served as his own model in creating the world (for what is there in God which is not God?), and he with his own image reached down to humanity.

Johannes Kepler (1571–1630) German astronomer
The Harmonies of the World [Harmonices Mundi], Book 4, ch. 1 (1618)

Kepler, Johannes -- The Harmonies of the World [Harmonices Mundi], Book 3, ch. 1 (1618)

Dave — Wed, 04 Feb 2015 14:34:07 +0000

Geometry is one and eternal shining in the mind of God. That share in it accorded to humans is one of the reasons that humanity is the image of God.

Johannes Kepler (1571–1630) German astronomer
The Harmonies of the World [Harmonices Mundi], Book 3, ch. 1 (1618)

Other translations:

"Geometry, co-eternal with God and shining in the divine Mind, gave God the pattern ... by which he laid out the world so that it might be best and most beautiful and finally most like the Creator."
"Geometry is one and eternal shining in the mind of God. That share in it accorded to men is one of the reasons that Man is the image of God."

Einstein, Albert -- “Geometry and Experience [Geometrie und Erfahrung],” lecture (27 Jan 1921)

Dave — Sun, 01 Feb 2004 16:00:00 +0000

Insofar as statements of mathematics refer to reality, they are uncertain, and insofar as they are certain, they do not refer to reality.

[Insofern sich die Sätze der Mathematik auf die Wirklichkeit beziehen, sind sie nicht sicher, und insofern sie sicher sind, beziehen sie sich nicht auf die Wirklichkeit.]

Albert Einstein (1879–1955) German-American physicist
“Geometry and Experience [Geometrie und Erfahrung],” lecture (27 Jan 1921)
(Source)

Sometimes given as "Insofar as the statements of geometry speak about reality, they are not certain, and in so far as they are certain, they do not speak about reality. [Sofern die Sätze der Geometrie streng gültig sind, beziehen sie sich nicht auf de Wirklichkeit; sofern sie sich auf dei Wirklichkeit beziehen, sind sie nicht streng gültig.]" -- this version was popularized by Karl Popper, but it was from a misquote by Morris Schlick.

Twain, Mark -- Interview (1889) by Rudyard Kipling, Elmira, New York, From Sea to Sea, Part 2, ch. 37 “An Interview with Mark Twain” (1899)

Dave — Sun, 01 Feb 2004 16:00:00 +0000

Get your facts first, and then you can distort them as much as you please.

Mark Twain (1835–1910) American writer [pseud. of Samuel Clemens]
Interview (1889) by Rudyard Kipling, Elmira, New York, From Sea to Sea, Part 2, ch. 37 “An Interview with Mark Twain” (1899)
(Source)

Broader context:

"Personally I never care for fiction or story-books. What I like to read about are facts and statistics of any kind. If they are only facts about the raising of radishes, they interest me. Just now, for instance, before you came in" -- he pointed to an encyclopædia on the shelves -- "I was reading an article about 'Mathematics.' Perfectly pure mathematics.
"My own knowledge of mathematics stops at 'twelve times twelve,' but I enjoyed that article immensely. I didn't understand a word of it: but facts, or what a man believes to be facts, are always delightful. That mathematical fellow believed in his facts. So do I. Get your facts first, and" -- the voice dies away to an almost inaudible drone -- "then you can distort 'em as much as you please."

Variant: "Get the facts first. You can distort them later."

For more discussion of this quotation, see "Get your facts first, and then you can distort them… (Barry Popik).