It has long seemed ridiculous to me to suppose that the nature of things has been so poor and stingy that it provided souls only to such a trifling mass of bodies on our globe, like human bodies, when it could have given them to all, without interfering with its other ends.

Nothing is more important than to see the sources of invention which are, in my opinion more interesting than the inventions themselves.

God's relation to spirits is not like that of a craftsman to his work, but also like that of a prince to his subjects.

It is unworthy of excellent men to lose hours like slaves in the labor of calculation which could be relegated to anyone else if machines were used.

For since it is impossible for a created monad to have a physical influence on the inner nature of another, this is the only way in which one can be dependent on another.

Every present state of a simple substance is the natural consequence of its preceding state, in such a way that its present is big with its future.

There is nothing without reason.