If I had stayed for other people to make my tools and things for me, I had never made anything.

He who thinks half-heartedly will not believe in God; but he who really thinks has to believe in God.

Gravity explains the motions of the planets, but it cannot explain who sets the planets in motion.

The instinct of brutes and insects can be the effect of nothing else than the wisdom and skill of a powerful ever-living agent.

The description of right lines and circles, upon which geometry is founded, belongs to mechanics. Geometry does not teach us to draw these lines, but requires them to be drawn.

The Synthesis consists in assuming the Causes discovered and established as Principles, and by them explaining the Phænomena proceeding from them, and proving the Explanations.

A body in motion tends to stay in motion unless acted on by an outside force.