Chance ... must be something more than the name we give to our ignorance.

A scientist worthy of his name, about all a mathematician, experiences in his work the same impression as an artist; his pleasure is as great and of the same nature.

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

It may happen that small differences in the initial conditions produce very great ones in the final phenomena. A small error in the former will produce an enormous error in the later. Prediction becomes impossible, and we have the fortuitous phenomena.

It is with logic that one proves; it is with intuition that one invents.

Astronomy is useful because it raises us above ourselves; it is useful because it is grand; .... It shows us how small is man's body, how great his mind, since his intelligence can embrace the whole of this dazzling immensity, where his body is only an obscure point, and enjoy its silent harmony.

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