Whoever wishes to become a philosopher must learn not to be frightened by absurdities.

Never let yourself be diverted, either by what you wish to believe, or what you think could have beneficent social effects if it were believed; but look only and solely at what are the facts.

Three passions, simple but overwhelmingly strong, have governed my life: the longing for love, the search for knowledge, and unbearable pity for the suffering of mankind.

Fervent religious believers sacrifice pleasures of the body, but instead enjoy pleasures of the mind, including the joy of knowing that those men who didn't follow their religion would be tortured for eternity.

When we have told how things behave when they are electrified, and under what circumstances they are electrified, we have told all there is to know

If a philosophy is to bring happiness it should be inspired by kindly feelings. Marx pretended that he wanted the happiness of the proletariat; what he really wanted was the unhappiness of the bourgeois.

The greatest challenge to any thinker is stating the problem in a way that will allow a solution.