Progress has not followed a straight ascending line, but a spiral with rhythms of progress and retrogression, of evolution and dissolution.

Never by reflection, but only by doing is self- knowledge possible to one.

Truth is a torch, but a terrific one; therefore we all try to reach it with closed eyes, lest we should be scorched.

The nude is the perfect expression of freedom. Freedom to be.

Beauty is everywhere a welcome guest.

Hypotheses are only the pieces of scaffolding which are erected round a building during the course of construction, and which are taken away as soon as the edifice is completed.

With knowledge comes more doubt.