How many famous and high-spirited heroes have lived a day too long?

At sixteen, the adolescent knows about suffering because he himself has suffered, but he barely knows that other beings also suffer.

Why should we build our happiness on the opinons of others, when we can find it in our own hearts?

In truth, laws are always useful to those with possessions and harmful to those who have nothing; from which it follows that the social state is advantageous to men only when all possess something and none has too much.

Chemistry... is like the maid occupied with daily civilisation; she is busy with fertilisers, medicines, glass, insecticides ... for she dispenses the recipes.

We do not know either unalloyed happiness or unmitigated misfortune. Everything in this world is a tangled yarn; we taste nothing in its purity; we do not remain two moments in the same state. Our affections as well as bodies, are in a perpetual flux.

As soon as any man says of the affairs of the State "What does it matter to me?" the State may be given up for lost.