Indeed every monad must be different from every other. For there are never in nature two beings, which are precisely alike, and in which it is not possible to find some difference which is internal, or based on some intrinsic quality.

Reality cannot be found except in One single source, because of the interconnection of all things with one another.

Nature does not make leaps.

What is is what must be.

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

We should like Nature to go no further; we should like it to be finite, like our mind; but this is to ignore the greatness and majesty of the Author of things.

The pleasure we obtain from music comes from counting, but counting unconsciously. Music is nothing but unconscious arithmetic.