The word ‘slavery’ and ‘right’ are contradictory, they cancel each other out. Whether as between one man and another, or between one man and a whole people, it would always be absurd to say: "I hereby make a covenant with you which is wholly at your expense and wholly to my advantage; I will respect it so long as I please and you shall respect it as long as I wish.

A feeble body weakens the mind.

We lose all that time which we might employ better.

All through life a man has need of a counsellor and guide.

Our greatest evil flows from ourselves.

The abuse of books kills science. Believing that we know what we have read, we believe that we can dispense with learning it.

To renounce liberty is to renounce being a man, to surrender the rights of humanity and even its duties. For he who renounces everything no indemnity is possible. Such a renunciation is incompatible with man's nature; to remove all liberty from his will is to remove all morality from his acts.