It must not be supposed, when we speak of the philosophy of Greece, that we refer only to the mainland of what is now called Greece. Very early in history, Greeks of the mainland migrated to the islands of the Aegean, to Sicily, to the South of Italy, to the coast of Asia Minor, and elsewhere, and founded flourishing colonies. The Greece of philosophy includes all these places. It is to be thought of rather racially than territorially. It is the philosophy of the men of Greek race, wherever they happened to be situated. And in fact the first period of Greek philosophy deals exclusively with the thoughts of these colonial Greeks. It was not till just before the time of Socrates that philosophy was transplanted to the mainland.
Greek philosophy falls naturally into three periods. The first may be roughly described as pre-Socratic philosophy, though it does not include the Sophists who were both the contemporaries and the predecessors of Socrates. This period is the rise of Greek philosophy. [{19}] Secondly, the period from the Sophists to Aristotle, which includes Socrates and Plato, is the maturity of Greek philosophy, the actual zenith and culmination of which is undoubtedly the system of Aristotle. Lastly, the period of post-Aristotelian philosophy constitutes the decline and fall of the national thought. These are not merely arbitrary divisions. Each period has its own special characters, which will be described in the sequel.
A few words must be said of the sources of our knowledge of pre-Socratic philosophy. If we want to know what Plato and Aristotle thought about any matter, we have only to consult their works. But the works of the earlier philosophers have not come down to us, except in fragments, and several of them never committed their opinions to writing. Our knowledge of their doctrines is the result of the laborious sifting by scholars of such materials as are available. Luckily the material has been plentiful. It may be divided into three classes. First come the fragments of the original writings of the philosophers themselves. These are in many cases long and important, in other cases scanty. Secondly, there are the references in Plato and Aristotle. Of these by far the most important are to be found in the first book of Aristotle's "Metaphysics," which is a history of philosophy up to his own time, and is the first attempt on record to write a history of philosophy. Thirdly, there is an enormous mass of references, some valuable, some worthless, contained in the works of later, but still ancient, writers.
THE IONICS.
The earliest Greek philosophers belong to what in after times came to be called the Ionic school. The name was derived from the fact that the three chief representatives of this school, Thales, Anaximander, and Anaximenes, were all men of Ionia, that is to say, the coast of Asia Minor.
Thales
As the founder of the earliest school in history, Thales of Miletus is generally accounted the founder and father of all philosophy. He was born about 624 B.C. and died about 550 B.C. These dates are approximate, and it should be understood that the same thing is true of nearly all the dates of the early philosophers. Different scholars vary, sometimes as much as ten years, in the dates they give. We shall not enter into these questions at all, because they are of no importance. And throughout these lectures it should be understood that the dates given are approximate.
Thales, at any rate, was a contemporary of Solon and Croesus. He was famous in antiquity for his mathematical and astronomical learning, and also for his practical sagacity and wisdom. He is included in [{21}] all the accounts of the Seven Sages. The story of the Seven Sages is unhistorical, but the fact that the lists of their names differ considerably as given by different writers, whereas the name of Thales appears in all, shows with what veneration he was anciently regarded. An eclipse of the sun occurred in 585 B.C., and Thales is alleged to have predicted it, which was a feat for the astronomy of those times. And he must have been a great engineer, for he caused a diversion of the river Halys, when Croesus and his army were unable to cross it. Nothing else is known of his life, though there were many apocryphal stories.