The soul, which is the first principle of life, is not a body, but the act of a body; just as heat, which is the principle of calefaction, is not a body, but an act of a body.

God himself would not permit evil in this world if good did not come of it for the benefit and harmony of the universe.

Mistakes are made on two counts: an argument is either based on error or incorrectly developed.

What can be accomplished by a few principles is not effected by many. But it seems that everything we see in the world can be accounted for by other principles, supposing God did not exist. For all natural things can be reduced to one principle, which is nature, and all voluntary things can be reduced to one principle, which is human reason, or will. Therefore there is no need to suppose God's existence.

For it is necessary in every practical science to proceed in a composite (i.e. deductive) manner. On the contrary in speculative science, it is necessary to proceed in an analytical manner by breaking down the complex into elementary principles.

The last end of every maker, as such, is himself, for what we make we use for our own sake; and if at any time a man make a thing for the sake of something else, it is referred to his own good, whether his use, his pleasure, or his virtue.

Friendship is the source of the greatest pleasures, and without friends even the most agreeable pursuits become tedious.