And I shall always hold myself more obliged to those by whose favour I enjoy uninterrupted leisure than to any who might offer me the most honourable positions in the world.

An optimist may see a light where there is none, but why must the pessimist always run to blow it out?

Here I beg you to observe in passing that the scruples that prevented ancient writers from using arithmetical terms in geometry, and which can only be a consequence of their inability to perceive clearly the relation between these two subjects, introduced much obscurity and confusion into their explanations.

Science is practical philosophy.

So far, I have been a spectator in this theater which is the world, but I am now about to mount the stage, and I come forward masked.

Common sense is the most fairly distributed thing in the world, for each one thinks he is so well-endowed with it that even those who are hardest to satisfy in all other matters are not in the habit of desiring more of it than they already have.

The object of music is a Sound. The end; to delight, and move various Affections in us.