In the 5th century, the center of philosophy moved to Italy. Parmenides, a Greek philosopher of Elea in southern Italy was the one who founded Eleaticism – the leading pre-Socratic school of Greek thought. His general teaching has been preserved and revised from a lengthy three-part verse composition titled On Nature. He countered Heraclitus’ theory of opposites and was also the first to draw a distinction between reality and human perception which later laid the groundwork for several notions in Western philosophy.
Parmenides held that the multiplicity of existing things, their changing forms, and motion, are but an appearance of a single eternal reality – which he called Being, thus giving rise to the Parmenidean principle, monism: all is one.
From this concept of Being, he went on to say that all claims of change or of non-Being – as Heraclitus puts it, that everything came from nothing – are illogical. Because nothing comes from nothing, and what exists has always existed because it can not be nothing. He introduced the method of basing claims about appearances on a logical concept of Being, he is considered one of the founders of metaphysics. His contributions are evident by the fact that one of the most widely known Plato’s works of dialogues was named after him.