Only a development of thought achieved through the self-education of the whole man can prevent any body of thought whatsoever from becoming a poison; can prevent enlightenment from becoming an agent of death.

To decide to become a philosopher seemed as foolish to me as to decide to become a poet.

At the present moment, the security of coherent philosophy, which existed from Parmenides to Hegel, is lost.

I began the study of medicine, impelled by a desire for knowledge of facts and of man. The resolution to do disciplined work tied me to both laboratory and clinic for a long time to come.

On the question of the world as a whole, science founders. For scientific knowledge the world lies in fragments, the more so the more precise our scientific knowledge becomes.

An ideology is a complex of ideas or notions which represents itself to the thinker as an absolute truth for the interpretation of the world and his situation within it; it leads the thinker to accomplish an act of self-deception for the purpose of justification, obfuscation and evasion in some sense or other to his advantage.

What makes us afraid is our great freedom in the face of the emptiness that has still to be filled.