Thus we see that Lucretius, although an excellent poet, was neither a good evolutionist nor a first-rate philosopher. In his abandonment of Aristotle he discarded the only phase of Greek thought which had come near to true conceptions of evolution, and in expounding the doctrine of spontaneous generation, he fostered an idea that was to prove of almost infinite harm to the evolution idea. There was no one to carry on the work. Greece was no longer a great nation; her “philosophers” were mostly second-rate tutors. Rome produced no naturalists of note, Pliny, the greatest, being of small capacity for reliable observation. The Greeks had done much; they had asked questions and insofar as they were able, had given answers. They left the world face to face with the problem of natural causation, and their ideas endured as a basis for the work of future scientists and philosophers. THE GREEK PERIODS[1] GENERAL CONCEPTION DIVISIONS OF THE SCHOOLS OF NATURE: ~Mythological~ The prehistoric traditions. I. ~The Three Earliest Schools.~ The Ionians: Thales (624-548), FIRST PERIOD: Anaximander (611-547), Anaximenes (588-524), Diogenes (440- ). ~Naturalistic~ The Pythagoreans (580-430). The Eleatics. Xenophanes (576-480), Parmenides (544- ). II. ~The Physicists.~ ~Materialistic~ Heraclitus (535-475), Empedocles (Early) (495-435), Democritus (450- ), Anaxagoras (500-428). SECOND PERIOD: Socrates (470-399), Plato (427-347). ~Teleological~ Aristotle (384-322). The Post-Aristotelians, (so-called Peripatetics), including Theophrastus, Preaxagoras, Herophilus, and others. THIRD PERIOD: A. I. ~The Stoics.~ II. ~The Epicureans.~ Epicurus (341-270). ~Materialistic~ III. ~The Sceptics.~ (Late) B. I. ~Eclecticism.~ Galen (131-201 A. D.). CHAPTER II. FROM THE CHRISTIAN FATHERS TO KANT. Inasmuch as almost the entire learning of Europe for several centuries was under the protection and rule of the church, it is important that we examine in some detail the fate of evolution at the hands of that organization.