There is nothing waste, nothing sterile, nothing dead in the universe; no chaos, no confusions, save in appearance.

Thus God alone is the primary Unity, or original simple substance, from which all monads, created and derived, are produced.

Men act like brutes in so far as the sequences of their perceptions arise through the principle of memory only, like those empirical physicians who have mere practice without theory.

It is worth noting that the notation facilitates discovery. This, in a most wonderful way, reduces the mind's labour.

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

Music is a hidden arithmetic exercise of the soul, which does not know that it is counting.

The knowledge which we have acquired ought not to resemble a great shop without order, and without an inventory; we ought to know what we possess, and be able to make it serve us in need.