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.

the essence of philosophy is not the possession of the truth but the search for truth. ... Philosophy means to be on the way. Its questions are more essential than its answers, and every answer becomes a new question.

Only as an individual can man become a philosopher.

Man is always something more than what he knows of himself. He is not what he is simply once and for all, but is a process; he is not merely an extant life, but is, within that life, endowed with possibilities through the freedom he possesses to make of himself what he will by the activities on which he decides.

Everything depends therefore on encountering thought at its source. Such thought is the reality of man's being, which achieved consciousness and understanding of itself through it.

Reason is like an open secret that can become known to anyone at any time; it is the quiet space into which everyone can enter through his own thought

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.