A Sunday school is a prison in which children do penance for the evil conscience of their parents.

The effort to reconcile science and religion is almost always made, not by theologians, but by scientists…the theologians...are smart enough to see that the two things are implacably and eternally antagonistic.

I believe that religion, generally speaking, has been a curse to mankind - that its modest and greatly overestimated services on the ethical side have been more than overcome by the damage it has done to clear and honest thinking

There seems to be a terrible misunderstanding on the part of a great many people to the effect that when you cease to believe you may cease to behave.

It is now quite lawful for a Catholic woman to avoid pregnancy by a resort to mathematics, though she is still forbidden to resort to physics or chemistry.

For men become civilized, not in proportion to their willingness to believe, but in proportion to their readiness to doubt.