“To love is to place happiness in the heart of another.”

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.

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

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.

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

We may say, that not only the soul (the mirror of an indestructible universe) is indestructible, but also the animal itself is, although its mechanism is frequently destroyed in parts.

Music is nothing but unconscious arithmetic.

Aristotle defined virtues simply as the ways of behaving that are most conducive to happiness in life.

The state must declare the child to be the most precious treasure of the people. As long as the government is perceived as working for the benefit of the children, the people will happily endure almost any curtailment of liberty and almost any deprivation.

Do not feel envious of the happiness of those who live in a fool’s paradise, for only a fool will think that it is happiness.

I have what I have and I am happy I’ve lost what I’ve lost and I am still happy – outlook.

It’s like the people who believe they’ll be happy if they go and live somewhere else, but who learn it doesn’t work that way. Wherever you go, you take yourself with you. If you see what I mean.

Socialists are happy until they run out of other people’s money.

There is no greater sorrow than to recall a happy time when miserable.

The secret of happiness is very simple: let your interests be as wide as possible, and let your reactions to the things and persons that interest you be as far as possible friendly rather than hostile.