A man's knowledge may be said to be mature, in other words, when it has reached the most complete state of perfection to which he, as an individual, is capable of bringing it, when an exact correspondence is established between the whole of his abstract ideas and the things he has actually perceived for himself. His will mean that each of his abstract ideas rests, directly or indirectly, upon a basis of observation, which alone endows it with any real value; and also that he is able to place every observation he makes under the right abstract idea which belongs to it.

The inexpressible depth of music, so easy to understand and yet so inexplicable, is due to the fact that it reproduces all the emotions of our innermost being, but entirely without reality and remote from its pain… Music expresses only the quintessence of life and its events, never these themselves.

That a god like Jehovah should have created this world of misery and woe, out of pure caprice, and because he enjoyed doing it, and should then have clapped his hands in praise of his own work, and declared everything to be very good-that will not do at all!

Women remain children all their lives, for they always see only what is near at hand, cling to the present, take the appearance of a thing for reality, and prefer trifling matters to the most important.

How is it possible that suffering that is neither my own nor of my concern should immediately affect me as though it were my own, and with such force that is moves me to action?

Hope is the confusion of the desire for a thing with its probability.

A man can be himself only so long as he is alone.