Every soul is as a world apart, independent of everything else except 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.

In whatever manner God created the world, it would always have been regular and in a certain general order. God, however, has chosen the most perfect, that is to say, the one which is at the same time the simplest in hypothesis and the richest in phenomena.

Although the world is not perfect, it is yet the best that is possible.

[Wisdom is] the science of happiness or of the means of attaining the lasting contentment which consists in the continual achievement of a greater perfection or at least in variations of the same degree of perfection.

To love is to place our happiness in the happiness of another.

Music is a secret arithmetical exercise and the person who indulges in it does not realize that he is manipulating numbers.

There are two kinds of truths: those of reasoning and those of fact. The truths of reasoning are necessary and their opposite is impossible; the truths of fact are contingent and their opposites are possible.

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