The universe is composed of matter, and, as a system, is sustained by motion. Motion is not a property of matter, and without this motion the solar system could not exist. Were motion a property of matter, that undiscovered and undiscoverable thing, called perpetual motion, would establish itself. It is because motion is not a property of matter, that perpetual motion is an impossibility in the hand of every being, but that of the Creator of motion. When the pretenders to Atheism can produce perpetual motion, and not till then, they may expect to be credited.

Discourse to the Theophilanthropists (1798)