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.

Mathematical discoveries, small or great are never born of spontaneous generation They always presuppose a soil seeded with preliminary knowledge and well prepared by labour, both conscious and subconscious.

One would have to have completely forgotten the history of science so as to not remember that the desire to know nature has had the most constant and the happiest influence on the development of mathematics.

We also know how cruel the truth often is, and we wonder whether delusion is not more consoling.

Every good mathematician should also be a good chess player and vice versa.

It is by logic we prove. It is by intuition we discover.

Geometry is not true, it is advantageous.