Pre-Socratic philosophy is Greek ancient philosophy before Socrates (and includes schools contemporary to Socrates that were not influenced by him). In Classical antiquity, the Presocratic philosophers were called physiologoi (; in English, physical or natural philosophers). Aristotle called them physikoi ("physicists", after physis, "nature") because they sought natural explanations for phenomena, as opposed to the earlier theologoi (theologians), whose philosophical basis was supernatural. Diogenes Laërtius divides the physiologoi into two groups, Ionian and Italiote, led by Anaximander and Pythagoras, respectively.