We have no organ at all for knowledge, for truth: we know (or believe or imagine) precisely as much as may be useful in the interest of the human herd, the species: and even what is here called usefulness is in the end only a belief, something imagined and perhaps precisely that most fatal piece of stupidity by which we shall one day perish.

Here the ways of men part: if you wish to strive for peace of soul and pleasure, then believe; if you wish to be a devotee of truth, then inquire.

To those searching for truth -- not the truth of dogma and darkness but the truth brought by reason, search, examination, and inquiry, discipline is required. For faith, as well intentioned as it may be, must be built on facts, not fiction -- faith in fiction is a damnable false hope.

What then in the last resort are the truths of mankind? They are the irrefutable errors of mankind.

Belief in the truth commences with the doubting of all those truths we once believed.

The uninitiated are those who believe in nothing except what they can grasp in their hands, and who deny the existence of all that is invisible.