Happiness is not best achieved by those who seek it directly.

Each act of cruelty is eternally a part of the universe; nothing that happens later can make that act good rather than bad, or can confer perfection on the whole of which it is a part.

The most savage controversies are about matters as to which there is no good evidence either way.

The whole of theology, in regard to hell no less than to heaven, takes it for granted that Man is what is of most importance in the Universe of created beings. Since all theologians are men, this postulate has met with little opposition.

You find as you look around the world that every single bit of progress in humane feeling, every improvement in the criminal law, every step toward the diminution of war, every step toward better treatment of the colored races, or every mitigation of slavery, every moral progress that there has been in the world, has been consistently opposed by the organized churches of the world. I say quite deliberately that the christian religion, as organized in its churches, has been and still is the principle enemy of moral progress in the world.

In science the successors stand upon the shoulders of their predecessors; where one man of supreme genius has invented a method, a thousand lesser men can apply it. ... In art nothing worth doing can be done without genius; in science even a very moderate capacity can contribute to a supreme achievement.

It is not my prayer and humility that you cause things to go as you wish, but by acquiring a knowledge of natural laws.