Page:Early Greek philosophy by John Burnet, 3rd edition, 1920.djvu/89

Rh It was natural for Anaximenes to fix upon "air" as the primary substance; for, in the system of Anaximander, it occupied an intermediate place between the two fundamental opposites, the ring of flame and the cold, moist mass within it (§ 19). We know from Plutarch that he fancied air became warmer when rarefied, and colder when condensed. Of this he satisfied himself by a curious experimental proof. When we breathe with our mouths open, the air is warm; when our lips are closed, it is cold.

28. This argument brings us to an important point in the theory, which is attested by the single fragment that has come down to us. "Just as our soul, being air, holds us together, so do breath and air encompass the whole world." The primary substance bears the same relation to the life of the world as to that of man. Now this was the Pythagorean view; and it is also an early instance of the argument from the microcosm to the macrocosm, and so marks the beginning of an interest in physiological matters.

29. We turn now to the doxographical tradition concerning the formation of the world and its parts: