We distinguish the excellent man from the common man by saying that the former is the one who makes great demands on himself, and the latter who makes no demands on himself.

Whoever has not felt the danger of our times palpitating under his hand, has not really penetrated to the vitals of destiny, he has merely pricked the surface.

Life is a series of collisions with the future; it is not the sum of what we have been, but what we yearn to be.

The preoccupation with what should be is estimable only when the respect for what is has been exhausted.

Life is a series of collisions with the future.

To be surprised, to wonder, is to begin to understand. This is the sport, the luxury, special to the intellectual man.

The past will not tell us what we ought to do, but... what we ought to avoid.