The introduction of the terms "philosopher" and "philosophy" has been ascribed to the Greek thinker Pythagoras.
The history of philosophy is customarily divided into six periods: Ancient philosophy, Medieval philosophy, Renaissance philosophy, Early and Late Modern philosophy and Contemporary philosophy.
Ancient philosophy
Ancient philosophy is the philosophy of the Graeco-Roman world from the sixth century B.C.to the fourth century A.D. It is usually divided into three periods: the pre-Socratic period, the periods of Plato and Aristotle, and the post-Aristotelian period. Sometimes a fourth period is added that includes the Christian philosophers as well as Neo-Platonist ones The most important of the ancient philosophers are Plato and AristotleThe themes of ancient philosophy are: understanding the fundamental causes and principles of the universe.