The power of thought, the vast regions it can master.

Religion is based, I think, primarily and mainly upon fear.

Even if we could be certain that one of the world's religions were perfectly true, given the sheer number of conflicting faiths on offer, every believer should expect damnation purely as a matter of probability.

Physics is mathematical not because we know so much about the physical world, but because we know so little; it is only its mathematical properties that we can discover.

All the conditions of happiness are realized in the life of the man of science.

If the ordinary wage-earner worked four hours a day, there would be enough for everybody, and no unemployment — assuming a certain very moderate amount of sensible organization. This idea shocks the well-to-do, because they are convinced that the poor would not know how to use so much leisure.

The wise man thinks about his troubles only when there is some purpose in doing so; at other times he thinks about other things, or, if it is night, about nothing at all.