The more we come in contact with animals and observe their behaviour, the more we love them, for we see how great is their care of the young.

Beauty presents an indeterminate concept of Understanding, the sublime an indeterminate concept of Reason.

What are the aims which are at the same time duties? They are perfecting of ourselves, the happiness of others.

From such crooked wood as that which man is made of, nothing straight can be fashioned.

Freedom is the alone unoriginated birthright of man, and belongs to him by force of his humanity; and is independence on the will and co-action of every other in so far as this consists with every other person's freedom.

Metaphysics is a dark ocean without shores or lighthouse, strewn with many a philosophic wreck.

If man makes himself a worm he must not complain when he is trodden on.