The most tyrannical of governments are those which make crimes of opinions, for everyone has an inalienable right to his thoughts.

Philosophers conceive of the passions which harass us as vices into which men fall by their own fault, and, therefore, generally deride, bewail, or blame them, or execrate them, if they wish to seem unusually pious.

Schisms do not originate in a love of truth, which is a source of courtesy and gentleness, but rather in an inordinate desire for supremacy.

He who lives according to the guidance of reason strives as much as possible to repay the hatred, anger, or contempt of others towards himself with love or generosity. ...hatred is increased by reciprocal hatred, and, on the other hand, can be extinguished by love, so that hatred passes into love.

In proportion as we endeavor to live according to the guidance of reason, shall we strive as much as possible to depend less on hope, to liberate ourselves from fear, to rule fortune, and to direct our actions by the sure counsels of reason.

I should attempt to treat human vice and folly geometrically... the passions of hatred, anger, envy, and so on, considered in themselves, follow from the necessity and efficacy of nature... I shall, therefore, treat the nature and strength of the emotion in exactly the same manner, as though I were concerned with lines, planes, and solids.

Men will find that they can ... avoid far more easily the perils which beset them on all sides by united action.