Parmenides has been described as “the most original and important philosopher before Socrates,” and this was because he was the first to focus on the central metaphysical question: What is being?

According to Eleaticisim, all is one – a view known as “monism”.

Parmenides lived in the fifth century BC, and came from Elea, a Greek colony in southern Italy. He is remembered today as the founder of “Eleaticism”, one of the leading schools of ancient pre-Socratic philosophy.

According to Eleaticisim, all is one – a view known as “monism”.

Further, all reality is static and unchanging, and so the motion and change we experience is merely an illusion.

Parmenides defended a view of this sort in his work now known as On Nature.

This was written as a poem, in the traditional or Homeric form of hexameter verse, and it ran to about 800 verses (though only 150 have survived).

This challenging and profound poem tells of the journey of a young man who meets a goddess who tells him: “You are to find out everything: both the steadfast heart of well-founded Truth, and the opinions of mortals, in which there is no true reliability.”

In the poem Parmenides goes on to argue that “being” (that which is or exists) is one, in the sense that there exists only one thing, or alternatively that there exists only one substance or one kind of substance.

This one and only thing that exists must, according to Parmenides, possess a certain set of properties.

Parmenides states that that-which-is “is ungenerated and indestructible; whole, of one kind and unwavering and complete. Nor was it ever, nor will it be, since now it is, all together, one, continuous… it is beginningless and ceaseless… The same and remaining in the same state.”

In other words, there is a single and indivisible reality which cannot be born and cannot be destroyed, and which is eternal, changeless, motionless and homogeneous.

By contrast, the world we experience with our senses contains a multiplicity of things which are always changing.

But this world of our senses is entirely non-existent and we should only trust in the world disclosed by reason.

This division between a real world of static being and a deceptive world of change and diversity was to exert great influence on subsequent philosophical thinking, especially on Plato (who wrote a dialogue entitled “Parmenides”) and the Neoplatonists.

Dr Nick Trakakis teaches Philosophy and Religious Studies at Monash and Deakin Universities.

His most recent book is The End of Philosophy of Religion, published by Continuum in London.