A man of talent will strive for money and reputation; but the spring that moves genius to the production of its works is not as easy to name

A man of genius can hardly be sociable, for what dialogues could indeed be so intelligent and entertaining as his own monologues?

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.

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.

Reading is merely a surrogate for thinking for yourself; it means letting someone else direct your thoughts. Many books, moreover, serve merely to show how many ways there are of being wrong, and how far astray you yourself would go if you followed their guidance. You should read only when your own thoughts dry up, which will of course happen frequently enough even to the best heads; but to banish your own thoughts so as to take up a book is a sin against the holy ghost; it is like deserting untrammeled nature to look at a herbarium or engravings of landscapes.

There is only one healing force, and that is nature; in pills and ointments there is none. At most they can give the healing force of nature a hint about where there is something for it to do.

Optimism is not only a false but also a pernicious doctrine, for it presents life as a desirable state and man's happiness as its aim and object. Starting from this, everyone then believes he has the most legitimate claim to happiness and enjoyment. If, as usually happens, these do not fall to his lot, he believes that he suffers an injustice, in fact that he misses the whole point of his existence.