too, productive of the most important effects.

Whatever human reason could either conclude or conjecture concerning them, made, as it were, two chapters, though no doubt two very important ones, of the science which pretended to give an account of the origin and revolutions of the great system of the universe. But in the universities of Europe, where philosophy was taught only as subservient to theology, it was natural to dwell longer upon these two chapters than upon any other of the science. They were gradually more and more extended, and were divided into many inferior chapters, till at last the doctrine of spirits, of which so little can be known, came to take up as much room in the system of philosophy as the doctrine of bodies, of which so much can be known. The doctrines concerning those two subjects were considered as making two distinct sciences.