PHYSICIST

Life
Ancient Greek philosopher and theoretical physicist, Parmenides is considered the leading exponent of the Eleatic School of philosophy founded by the poet Xenophanes at Colophon, with whom he studied. He was also heavily influenced by the Pythagoreans, and his philosophy is suffused with doubt of the validity of the evidence of the senses. (Heracleitus, too, wondered how objective logic really is.)


Work
Parmenides' long verse composition "On nature" is an exposition of his philosophical ideas and his attempts at an interpretation of the world. In his view, "what exists" is one, infinite and indivisible, eternal and unchanging, and in its oneness the multitude of sensible things and appearances is mere illusion. As true "being" (on) differs from that which we receive through our senses, so also scientific knowledge differs from subjective opinion. Where Heracleitus is the philosopher of becoming, Parmenides is the philosopher of being.

According to Parmenides, the world is a multiplicity of phenomena; in this world every phenomenon or object is something and at the same time is not something else. That is, everything in this world has its own nature, its own properties, its own characteristics. This underlies his theory of being and non-being. Everything is and at the same time is not. This explains why for Parmenides there is no coming-into-being or perishing. Objective multiplicity is merely a belief. The truth is only what can be expressed by the one "on". Knowledge achieves the full conception of being when understanding coincides with existence, that is, when one can comprehend the truth of his existence. The main constituents of the world are heat and cold. In the sphere occupied by this world heat occupies the place of being. Recognised by Plato as one of the founders of rationalism and one of the most important Greek philosophers, Parmenides may be considered the father of classical metaphysics. Only fragments of his writings survive