Looking back from today's vantage, Eisenstein's mathematics appear to us more up to date than ever. It is not so much the harvest of **theorems**, nor the creation of full-fledged theories, but the way of looking at things which amazes us...

— Norbert Schappacher in

Less depends upon the choice of words than upon this, that their introduction shall be justified by pregnant **theorems**.

— "Gauss's Abstract of the Disquisitiones Generales circa Superficies Curvas presented to the Royal Society of Gottingen" (1827) Tr. James Caddall Morehead & Adam Miller Hiltebeitel in

In other words, the fact that the criterion we happen to use has a fine ancestry of highbrow statistical **theorems** does not justify its use. Such justification must come from empirical evidence that it works.

— Shewhart, Walter A. (1931).

The first sign of senility is that a man forgets his **theorems**, the second sign is that he forgets to zip up, the third sign is that he forgets to zip down.

— Attributed in Paul Hoffman,

— This has also been attributed, with variants, to Paul Erd?s, who repeated the remark.

There are infinitely many variations of the initial situation and therefore no doubt indefinitely many **theorems** of moral geometry.

— Chapter III, Section 21, pg. 126

There are numerous **theorems** in economics that rely upon mathematically fallacious propositions.

— Chapter 12, Don't Shoot Me, I'm Only The Piano, p. 259

A mathematician is a device for turning coffee into **theorems**.

— Alfréd Rényi. Popularly attributed to Paul Erd?s, who quoted him. (Bruce Schechter,

If I compare arithmetic with a tree that unfolds upward into a multitude of techniques and **theorems** while its root drives into the depths, then it seems to me that the impetus of the root.

— Gottlob Frege, Montgomery Furth (1964)

The Pythagoreans were... familiar with the construction of a polygon equal in area to a given polygon and similar to another given polygon. This problem depends upon several important and somewhat advanced **theorems**, and testifies to the fact that the Pythagoreans made no mean progress in geometry.

—

A mathematician is a machine for turning coffee into **theorems**.

— Popularly attributed to Paul Erd?s, who was quoting Alfréd Rényi (Bruce Schechter,

A mathematician is a person who can find analogies between **theorems** ; a better mathematician is one who can see analogies between proofs and the best mathematician can notice analogies between theories. One can imagine that the ultimate mathematician is one who can see analogies between analogies.

— Stefan Banach, in Banach Spaces and Their Applications in Analysis: Proceedings of the ... (2007), p.5