Virtue is as little to be acquired by learning as genius; nay, the idea is barren, and is only to be employed as an instrument, in the same way as genius in respect to art. It would be as foolish to expect that our moral and ethical systems would turn out virtuous, noble, and holy beings, as that our aesthetic systems would produce poets, painters, and musicians.

Because Christian morality leaves animals out of account, they are at once outlawed in philosophical morals; they are mere 'things,' mere means to any ends whatsoever. They can therefore be used for vivisection, hunting, coursing, bullfights, and horse racing, and can be whipped to death as they struggle along with heavy carts of stone. Shame on such a morality that is worthy of pariahs, and that fails to recognize the eternal essence that exists in every living thing, and shines forth with inscrutable significance from all eyes that see the sun!

There are, first of all, two kinds of authors: those who write for the subject's sake, and those who write for writing's sake.

Truth is no harlot who throws her arms round the neck of him who does not desire her; on the contrary, she is so coy a beauty that even the man who sacrifices everything to her can still not be certain of her favors.

As the biggest library if it is in disorder is not as useful as a small but well-arranged one, so you may accumulate a vast amount of knowledge but it will be of far less value than a much smaller amount if you have not thought it over for yourself.

For an act to be moral the intention must be based on compassion, not duty. We do something because we want to do it, because we feel we have to do it, not because we ought to do it. And even if our efforts fail - or we never even get to implement them - we are still moral because our motivation was based on compassion.

There is only one inborn error. and that is the notion that we exist in order to be happy.