Absolute certainty is a privilege of uneducated minds and fanatics. - It is, for scientific folk, an unattainable ideal.

- Cassius Jackson Keyser

The pursuit of excellence is the proper vocation of man.

- Cassius Jackson Keyser

The present is no more exempt from the sneer of the future than the past has been.

- Cassius Jackson Keyser

Mathematics, even in its present and most abstract state, is not detached from life. It is just the ideal handling of the problems of life.

- Cassius Jackson Keyser

The validity of mathematical propositions is independent of the actual world-the world of existing subject-matters-is logically prior to it, and woul…

- Cassius Jackson Keyser

The next-most difficult thing in the world is to get perspective. The most difficult is to keep it.

- Cassius Jackson Keyser

If people would stop objectifying abstractions (which they probably never will), or if they would stop objectifying the abstractions they make consci…

- Cassius Jackson Keyser

[The] humanization of mathematical teaching, the bringing of the matter and the spirit of mathematics to bear not merely upon certain fragmentary fac…

- Cassius Jackson Keyser

It is commonly, but erroneously, believed that it is easy to ask questions. A fool, it is said, can ask questions that a wise man cannot answer. The …

- Cassius Jackson Keyser