A GREAT discovery solves a great problem but there is a grain of discovery in any problem.

Quite often, when an idea that could be helpful presents itself, we do not appreciate it, for it is so inconspicuous. The expert has, perhaps, no more ideas than the inexperienced, but appreciates more what he has and uses it better.

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

What is the difference between method and device? A method is a device which you use twice.

Beauty in mathematics is seeing the truth without effort.

If there is a problem you can't solve, then there is an easier problem you can't solve: find it.

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