The resistance to a new idea increases by the square of its importance.

Literature is inexhaustible, with every book a homage to infinity

Ants and savages put strangers to death.

Religions which have any very strong hold over men's actions have generally some instinctive basis.

The degree of one's emotions varies inversely with one's knowledge of the facts - the less you know the hotter you get.

[There has been] every kind of cruelty practiced upon all sorts of people in the name of religion.

I say quite deliberately that the Christian religion, as organized in its Churches, has been and still is the principal enemy of moral progress in the world.