Under democracy one party always devotes its chief energies to trying to prove that the other party is unfit to rule—and both commonly succeed, and are right.

Religion is a conceited effort to deny the most obvious realities.

The liberation of the human mind has never been furthered by dunderheads.

The fundamental trouble with marriage is that it shakes a man's confidence in himself, and so greatly diminishes his general competence and effectiveness. His habit of mind becomes that of a commander who has lost a decisive and calamitous battle. He quite trusts himself thereafter.

All human progress, even in morals, has been the work of men who have doubted the current moral values, not of men who have whooped them up and tried to enforce them.

The scientist who yields anything to theology, however slight, is yielding to ignorance and false pretenses, and as certainly as if he granted that a horse-hair put into a bottle of water will turn into a snake.

Socialist: A man suffering from an overwhelming conviction to believe what is not true.