losophers, and their evident failures to understand the problems which they attacked are quite to be expected. As has been said, they sought the theory before they searched for the fact, and having attained it they interpreted all facts in the light of the theory. And if that was wrong—as it very often was—the whole thing was wrong, because only the theory was studied and no one knew anything about the mistake.
But with all their superstitions and erroneous ideas, the Greeks possessed an overpowering curiosity regarding the multitudinous natural objects which they saw about them. Thales, an Ionian astronomer who lived from 624–548 B. C. was the first, so far as we know, to substitute a natural explanation of "creation" for the prehistoric myths. He believed that water was the fundamental substance from which all things come, and because of which they exist. Thus the idea of the marine origin of life, held today by many prominent biologists, is found to be extremely ancient. Of course, had Thales lived in a land-locked country instead of one surrounded by a warm, highly populated sea, his ideas might well have been different. Thus we must, at the very outset, attribute to environment as well as to intellect the reliability of an important Greek idea.
Anaximander (611–547), another astronomer, was the first important Greek evolutionist. He believed that the earth first existed in a fluid state. From its slow drying up were produced all living creatures, the first being man. These
