“Every mind has a horizon in respect to its present intellectual capacity but not in respect to its future intellectual capacity.”

There is no way in which a simple substance could begin in the course of nature, since it cannot be formed by means of compounding.

In symbols one observes an advantage in discovery which is greatest when they express the exact nature of a thing briefly and, as it were, picture it; then indeed the labor of thought is wonderfully diminished.

When God works miracles, he does not do it in order to supply the wants of nature, but those of grace. Whoever thinks otherwise, must needs have a very mean notion of the wisdom and power of God.

Although the whole of this life were said to be nothing but a dream and the physical world nothing but a phantasm, I should call this dream or phantasm real enough, if, using reason well, we were never deceived by it.

Now this connection or adaption of all created things with each, and of each with all the rest, means that each simple substance has relations which express all the others, and that consequently it is a perpetual living mirror of the universe.

One cannot explain words without making incursions into the sciences themselves, as is evident from dictionaries; and, conversely, one cannot present a science without at the same time defining its terms.

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

The greatness of a life can only be estimated by the multitude of its actions. We should not count the years, it is our actions which constitute our life.

Our reasonings are grounded upon two great principles, that of contradiction, in virtue of which we judge false that which involves a contradiction, and true that which is opposed or contradictory to the false.

Music is a secret and unconscious mathematical problem of the soul.

He who understands Archimedes and Apollonius will admire less the achievements of the foremost men of later times.

There is nothing without a reason.

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

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.

Virtue is the habit of acting according to wisdom.

There is a certain destiny of everything, regulated by the foreknowledge and providence of God in His works.