The moment one asks himself whether he is happy, he ceases to be so.

Christian morality (so called) has all the characters of a reaction.... In its horror of sensuality, it made an idol of asceticism, which has been gradually compromised away into one of legality. It holds out the hope of heaven and the threat of hell, as the appointed and appropriate motives to a virtuous life - in this falling far below the best of the ancients, and doing what lies in it to give to human morality an essentially selfish character.... It is essentially a doctrine of passive obedience; it inculcates submission to all authorities found established.

There is the greatest difference between presuming an opinion to be true, because, with every opportunity for contesting it, it has not been refuted, and assuming its truth for the purpose of not permitting its refutation.

The disease which inflicts bureaucracy and what they usually die from is routine.

Genius can only breathe freely in an atmosphere of freedom.

We can never be sure that the opinion we are endeavoring to stifle is a false opinion; and if we were sure, stifling it would be an evil still.

Stupidity is much the same all the world over