Lives and Opinions of Eminent Philosophers

​Archelaus was an Athenian or a Milesian; his father was Apollodorus, or according to some, Midon; he was a pupil of Anaxagoras and the teacher of Socrates. He was the first to transfer natural philosophy from Ionia to Athens, and was surnamed the Natural Philosopher; and indeed natural philosophy ended with him, Socrates having introduced ethics. Yet Archelaus himself also seems to have touched upon ethics; for he philosophized about laws and about what is noble and just; and Socrates, having received this from him, by developing it to the highest point was believed to have invented it himself. He also said that there are two causes of generation, heat and cold; that animals were generated from slime; and that what is just and what is base are so not by nature, but by convention.

​His doctrine runs as follows. He says that water, being melted by heat, produces earth insofar as it coalesces downwards owing to its fiery nature, but generates air insofar as it flows around. Whence the former is held in check by air, and the latter by the circular motion of fire. He also says that animals are generated from the warm earth, when it sends forth slime like milk to serve as nourishment; and in this way it also produced human beings. He was also the first to state that the production of the voice is the striking of the air; that the sea gathered together in the hollows by being strained through the earth; that the sun is the largest of the heavenly bodies, and that the universe is infinite. There have also been three other men named Archelaus: the chorographer of the lands traversed by Alexander; the author of the Peculiarities of Nature; and another who was a writer on the art of rhetoric.