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.

Newspapers are the second hand of history. This hand, however, is usually not only of inferior metal to the other hands, it also seldom works properly.

Intellect is invisible to the man who has none.

The less one, as a result of objective or subjective conditions, has to come into contact with people, the better off one is for it.

Materialism is the philosophy of the subject who forgets to take account of himself.

For our improvement we need a mirror.

Will minus intellect constitutes vulgarity.