What is is what must be.

To love is to find pleasure in the happiness of others.

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.

In my judgment an organic machine new to nature never arises, since it always contains an infinity of organs so that it can express, in its own way, the whole universe; indeed, it always contains all past and present times.

...a distinction must be made between true and false ideas, and that too much rein must not be given to a man's imagination under pretext of its being a clear and distinct intellection.

Justice is charity in accordance with wisdom.

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