Everything, even death, is active. Corpses are decomposed, transformed into plants, and nourish the living, which in their turn are the food of others. What is the principle of this universal activity?
This principle must be unique. The unvarying uniformity of the laws which control the march of the heavenly bodies, the movements of our globe, every species and genus of animal, plant, and mineral, indicates that there is one mover. If there were two, they would either differ, or be opposed to each other, or like each other. If they were different, there would be no harmony; if opposed, things would destroy each other; if like, it would be as if there were only one—a twofold employment.
I am encouraged in this belief that there can be but one principle, one single mover, when I observe the constant and uniform laws of the whole of nature.
The same gravitation reaches every globe, and causes them to tend towards each other in direct proportion, not to their surfaces, which might be the effect of an impelling fluid, but to their masses.
The square of the revolution of every planet is as the cube of its distance from the sun (which proves, one may note, what Plato had somehow divined, that the world is the work of the eternal geometrician).
The rays of light are reflected and refracted from end to end of the universe. All the truths of mathematics must be the same on the star Sirius as in our little home.
