Guessing before proving! Need I remind you that it is so that all important discoveries have been made?

It is the harmony of the diverse parts, their symmetry, their happy balance; in a word it is all that introduces order, all that gives unity, that permits us to see clearly and to comprehend at once both the ensemble and the details.

Pure logic could never lead us to anything but tautologies; it can create nothing new; not from it alone can any science issue.

Sociology is the science with the greatest number of methods and the least results.

Mathematical discoveries, small or great are never born of spontaneous generation.

It is by logic that we prove, but by intuition that we discover. To know how to criticize is good, to know how to create is better.

Thought is only a flash between two long nights, but this flash is everything.