People to whom their daily life appears too empty and monotonous easily grow religious; this is comprehensible and excusable, only they have no right to demand religious sentiments from those whose daily life is not empty and monotonous.

I looked for great men, but all I found were the apes of their ideals.

Necessity is an interpretation, not a fact.

Every attainment, every step forward in knowledge, follows from courage, from hardness against oneself, from cleanliness in relation to oneself.

Every extension of knowledge arises from making the conscious the unconscious.

Truth is only an illusion we have forgotten is an illusion.

My brother, are war and battle evil? Necessary, however, is the evil; necessary are the envy and the distrust and the back-biting among the virtues.