In the state of nature, wrong-doing is impossible; or, if anyone does wrong, it is to himself, not to another. For no one by the law of nature is bound to please another, unless he chooses, nor to hold anything to be good or evil, but what he himself, according to his own temperament, pronounces to be so; and, to speak generally, nothing is forbidden by the law of nature, except what is beyond everyone's power.

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

I call him free who is led solely by reason.

God is a thing that thinks.

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.

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

Many errors, of a truth, consist merely in the application of the wrong names of things.