Parmenides, << pahr MEHN ih deez >> (515?-450? B.C.), was the most important of the early Greek philosophers who lived before Socrates. Parmenides expressed his philosophy in a poem, On Nature. The complete poem has not survived, but large parts have been preserved.
Unlike previous Greek philosophers, Parmenides did not explain the origin of the world in terms of material substances, such as air or water. Instead, he deduced the nature of reality from logical arguments. Parmenides first argued that what is not is a notion that cannot properly be thought of or spoken of. Then he argued that if we eliminate what is not from our description of reality, what is turns out to be far different from what our senses tell us. Instead of a world made up of many changing things, what is is just one thing–unchanging, perfect, and without beginning or end. Parmenides was born in Elea, a Greek colony in Italy.
