He who understands Archimedes and Apollonius will admire less the achievements of the foremost men of later times.

To love is to be delighted by the happiness of someone, or to experience pleasure upon the happiness of another. I define this as true love.

Everything that is possible demands to exist.

God makes nothing without order, and everything that forms itself develops imperceptibly out of small parts.

Nature does not make leaps.

All the different classes of beings which taken together make up the universe are, in the ideas of God who knows distinctly their essential gradations, only so many ordinates of a single curve so closely united that it would be impossible to place others between any two of them, since that would imply disorder and imperfection. Thus men are linked with the animals, these with the plants and these with the fossils which in turn merge with those bodies which our senses and our imagination represent to us as absolutely inanimate.

If you have a clear idea of a soul, you will have a clear idea of a form; for it is of the same genus, though a different species.