If you want to expel religion from our European civilization, you can only do it by means of another system of doctrines; and such a system would from the outset take over all the psychological characteristics of religion—the same sanctity, rigidity and intolerance, the same prohibition of thought—for its own defence. You have to have something of the kind in order to meet the requirements of education. And you cannot do without education.

When a man has once brought himself to accept uncritically all the absurdities that religious doctrines put before him and even to overlook the contradictions between them, we need not be greatly surprised at the weakness of his intellect.

The demons of animism were usually hostile to man, but it seems as though man had more confidence in himself in those days than later on.

The more the fruits of knowledge become accessible to men, the more widespread is the decline of religious belief.

Humanity is in the highest degree irrational, so that there is no prospect of influencing it by reasonable arguments. Against prejudice one can do nothing.

At bottom God is nothing more than an exalted father.

Neither in my private life nor in my writings, have I ever made a secret of being an out-and-out unbeliever.

The religions of mankind must be classed among the mass-delusions of this kind. No one, needless to say, who shares a delusion ever recognizes it as such...