This document summarizes Greek philosophers from 1200 BC to 322 BC who contributed to early understandings of the cosmos and the mind. It describes their varying views on elements that compose the universe and human beings. Key figures discussed include Thales, Democritus, Heraclitus, Empedocles, Pythagoras, Anaxagoras, Hippocrates, Socrates, Plato, Aristotle, and Alexander the Great. Their diverse theories influenced later developments in medicine, logic, ethics, and psychology.