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

If we could sufficiently understand the order of the universe, we should find that it exceeds all the desires of the wisest men, and that it is impossible to make it better than it is, not only as a whole and in general but also for ourselves in particular, if we are attached, as we ought to be, to the Author of all, not only as to the architect and efficient cause of our being, but as to our master and to the final cause, which ought to be the whole aim of our will, and which can alone make our happiness.

But it is the knowledge of necessary and eternal truths which distinguishes us from mere animals, and gives us reason and the sciences, raising us to knowledge of ourselves and God. It is this in us which we call the rational soul or mind.

Nothing is more important than to see the sources of invention which are, in my opinion more interesting than the inventions themselves.

Every present state of a simple substance is the natural consequence of its preceding state, in such a way that its present is big with its future.

I hold that it is only when we can prove everything we assert that we understand perfectly the thing under consideration.

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