Lieben heißt, unser Glück in das Glück eines anderen zu legen.

Music is a calculation which the soul makes unconsciously in secret.

De quelque manière que Dieu aurait créé le monde, il aurait toujours été régulier et dans un certain ordre général. Mais Dieu a choisi celui qui est le plus parfait, c’est-à-dire celui qui est en même temps le plus simple en hypothèses et le plus riche en phénomènes...

And just as the same town, when looked at from different sides, appears quite different and is, as it were, multiplied in perspective, so also it happens that because of the infinite number of simple substances, it is as if there were as many different universes, which are however but different perspective representations of a single universe form the different point of view of each monad.

If you could blow the brain up to the size of a mill and walk about inside, you would not find consciousness.

[...] Et celui de la raison suffisante, en vertu duquel nous considérons qu’aucun fait ne saurait se trouver vrai, ou existant, aucune énonciation véritable, sans qu’il y ait une raison suffisante pourquoi il en soit ainsi et non pas autrement. Quoique ces raisons le plus souvent ne puissent point nous être connues.
[sect. 32]

When Sir A. Fountaine was at Berlin with Leibnitz in 1701, and at supper with the Queen of Prussia, she asked Leibnitz his opinion of Sir Isaac Newton. Leibnitz said that taking mathematicians from the beginning of the world to the time when Sir Isaac lived, what he had done was much the better half; and added that he had consulted all the learned in Europe upon some difficult points without having any satisfaction, and that when he applied to Sir Isaac, he wrote him in answer by the first post, to do so and so, and then he would find it.

The present is pregnant with the future; the future can be read in the past; the distant is expressed in the proximate.

It is unworthy of excellent men to lose hours like slaves in the labour of calculation which could safely be relegated to anyone else if machines were used.

(Describing, in 1685, the value to astronomers of the hand-cranked calculating machine he had invented in 1673.)

Los misterios se pueden explicar hasta donde es necesario para creerlos, pero no se les puede comprender, ni hacer entender cómo se verifican, a la manera que en la misma física explicamos hasta cierto punto muchas cualidades sensibles, pero de una manera imperfecta, porque no las comprendemos.

He who does not act does not exist.