Archelaus (philosopher) Archelaus (philosopher) Archelaus (; ; fl. 5th century BCE) was an Ancient Greek philosopher, a pupil of Anaxagoras, and may have been a teacher of Socrates. He asserted that the principle of motion was the separation of hot from cold, from which he endeavoured to explain the formation of the Earth and the creation of animals and humans. Archelaus was a philosopher of the Ionian School, called "Physicus" from having been the first to teach natural philosophy at Athens. This statement of Diogenes Laërtius, is contradicted by Clement of Alexandria, but the two may be reconciled by supposing that Archelaus
Hippo (philosopher) Hippo (philosopher) Hippo (; , "Hippon"; fl. 5th century BC) was a Pre-Socratic Greek philosopher. He is variously described as coming from Rhegium, Metapontum, Samos, and Croton, and it is possible that there was more than one philosopher with this name. Although he was a natural philosopher, Aristotle refused to place him among the other great Pre-Socratic philosophers "because of the paltriness of his thought." At some point Hippo was accused of atheism, but as his works have perished, we cannot be certain why. He was accused of impiety by the comic poet Cratinus in his "Panoptae", and, according to