System of Gorgias is idealistic. What it means is that nothing exists of appearance. Gorgias was perhaps a very deep philosopher; if not, he was a happy blunderer. His system makes us reach a conclusion many do not suspect.

When he says Being is non‑existent because it is out of time and of space, he is hardly a nihilist. He is an idealist, and very much of one. To most deep philosophers, even to the philosophers of the Catholic Church, God is immense and eternal. To Gorgias, Being in addition held to be non‑existent (as appearance), Being is the only thing existing. The completest idealism results. At least the reasoning leads thither whatever Gorgias may have meant by it, whithersoever he may have meant it to lead.