Archelaus lived in Athens. He was supposedly a pupil of Anaxagoras and the teacher of Socrates. He was a natural philosopher but also touched upon laws and what is just. He thought that things are just or ignoble because of convention not their nature. He believed that animals were made from mud and that the generating forces were heat (in motion) and cold (at rest). He beleived that all animals think, some much more quickly than others, and he also believed that animals and humans had evolved out of more primitive beings, and humans became distinguished from the rest and then began to build cities.