This miracle of analysis, this marvel of the world of ideas, an almost amphibian object between Being and Non-being that we call the . - Gottfried Wilhelm Leibniz

Nihil est sine ratione.
[There is nothing without a reason.]

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.)

[...] 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]