ARCHELAUS OF MILETUS, Greek philosopher, 5th century B.c., born probably at Athens, though Diogenes Laertius (ii. 16) says at Miletus. He was a pupil of Anaxagoras and is said by Ion of Chios (ap. Diog. Laert. ii. 23) to have been the teacher of Socrates. Some argue that this is probably only an attempt to connect Socrates with the Ionian school; others (e.g., Gomperz, Greek Thinkers) uphold the story. In general, he fol lowed Anaxagoras, but in his cosmology he went back to the earlier Ionians, postulating primitive matter, mingled with mind, which produces fire and water. From these spring animal life. No fragments of Archelaus remain; his doctrines have to be extracted from Diogenes Laertius, Simplicius, Plutarch and Hippolytus.
See IONIAN SCHOOL. ; for his ethical theories see T. Gomperz, Greek Thinkers (Eng. trans., 1900, vol. i. p. 402.