Thus the world is an organism, making no progress as a whole, but continually changing in its various parts.  In it all real things are individuals, not universals, as Plato thought.  And forms pass from individual to individual only.  Peleus, not humanity, is the parent of Achilles; the learned man only can teach the ignorant.  In the world-process there are several distinct stages, to each of which Aristotle devotes a special work, or series of works.  Beginning with the “four elements” and their changes, he works up through the mineral, vegetable, and animal worlds, to man, and thence through the spheral intelligences to the supreme, divine intelligence, on which the Whole depends.  Man stands on the dividing line between the temporal and the eternal; belonging with his animal part to the former, with his intelligence (which “enters from without”) to the latter.  He is an intelligence, of the same nature as the sphere-movers, but individuated by mutable matter in the form of a body, matter being in all cases the principle of individuation.  As intelligence, he becomes free; takes the guidance of his life into his own hand; and, first through ethics, politics, and aesthetics, the forms of his sensible or practical activity, and second through logic, science, and philosophy, the forms of his intellectual activity, he rises to divine heights and “plays the immortal.”  His supreme activity is contemplation.  This, the eternal energy of God, is possible for man only at rare intervals.

Aristotle, by placing his eternal forms in sensible things as their meaning, made science possible and necessary.  Not only is he the father of scientific method, inductive and deductive, but his actual contributions to science place him in the front rank of scientists.  His Zooelogy, Psychology, Logic, Metaphysics, Ethics, Politics, and Aesthetics, are still highly esteemed and extensively studied.  At the same time, by failing to overcome the dualism and supernaturalism of Plato, by adopting the popular notions about spheres and sphere-movers, by separating intelligence from sense, by conceiving matter as independent and the principle of individuation, and by making science relate only to the universal, he paved the way for astrology, alchemy, magic, and all the forms of superstition, retarding the advance of several sciences, as for example astronomy and chemistry, for many hundred years.

After Aristotle’s death, his school was continued by a succession of studious and learned men, but did not for many centuries deeply affect contemporary life.  At last, in the fifth century A.D., his thought found its way into the Christian schools, giving birth to rationalism and historical criticism.  At various times its adherents were condemned as heretics and banished, mostly to Syria.  Here, at Edessa and Nisibis, they established schools of learning which for several centuries were the most famous in the world.  The entire works of Aristotle were