John von Neumann was the only student I was ever afraid of.

Mathematics is the cheapest science. Unlike physics or chemistry, it does not require any expensive equipment. All one needs for mathematics is a pencil and paper.

There are many questions which fools can ask that wise men cannot answer.

To write and speak correctly is certainly necessary; but it is not sufficient. A derivation correctly presented in the book or on the blackboard may be inaccessible and uninstructive, if the purpose of the successive steps is incomprehensible, if the reader or listener cannot understand how it was humanly possible to find such an argument....

Mathematics is not a spectator sport!

An idea which can be used only once is a trick. If one can use it more than once it becomes a method.

Mathematics is being lazy. Mathematics is letting the principles do the work for you so that you do not have to do the work for yourself