The history of the world shows that when a mean thing was done, man did it; when a good thing was done, man did it.

Talent has the four seasons: spring, that is to say, the sowing of the seeds; summer, growth; autumn, the harvest; winter, intellectual death. But there is now and then a genius who has no winter, and, no matter how many years he may live, on the blossom of his thought no snow falls. Genius has the climate of perpetual growth.

The church in all ages and among all peoples has been the consistent enemy of the human race. Everywhere and at all times, it has opposed the liberty of thought and expression. It has been the sworn enemy of investigation and intellectual development. It has denied the existence of facts, the tendency of which was to undermine its power. It has always been carrying fagots to the feet of Philosophy. It has erected the gallows for Genius. It has built the dungeon for Thinkers.

I have no confidence in any religion that can be demonstrated only to children.

Reason, observation, and experience; the holy trinity of science.

It is perfectly delightful to take advantage of the conscientious labors of those who go through and through volume after volume, divide with infinite patience the gold from the dross, and present us with the pure and shining coin. Such men may be likened to bees who save us numberless journeys by giving us the fruit of their own.

Intellectual liberty is the air of the soul, the sunshine of the mind, and without it, the world is a prison, the universe is a dungeon.