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.

Thus, be it understood, to demonstrate a theorem, it is neither necessary nor even advantageous to know what it means.

Intuition is more important to discovery than logic.

Doubt everything or believe everything: these are two equally convenient strategies. With either we dispense with the need for reflection.

Every phenomenon, however trifling it be, has a cause, and a mind infinitely powerful, and infinitely well-informed concerning the laws of nature could have foreseen it from the beginning of the ages. If a being with such a mind existed, we could play no game of chance with him; we should always lose.

If nature were not beautiful, it would not be worth knowing, and if nature were not worth knowing, life would not be worth living

One geometry cannot be more true than another; it can only be more convenient.