You never step in the same river of thought twice, because neither you nor it are the same.

If it were possible to talk to the unborn, one could never explain to them how it feels to be alive, for life is washed in the speechless real.

[T]hat is the triumph of history - truth absolute is not at hand; the original with which to match the copy does not exist.

The educated man had throughout the ages found a way to covert passionate activity into silent and motionless pleasure. He can sit still in a room and not perish.

Time and rest are needed for absorption. Psychologists confirm that it is really in the summer that our muscles learn to skate and in the winter, how to swim.

Great cultural changes begin in affectation and end in routine.

Out of man's mind in free play comes the creation Science. It renews itself, like the generations, thanks to an activity which is the best game of homo ludens: science is in the strictest and best sense a glorious entertainment.