Development Of The Human Soul

Appendix 13. (1368).

What is the precise line separating Parmenides' system from Plato's? Basing our judgment on the only extant fragments of Parmenides, we must say that he was content to establish a theory of ens in general without applying it to the various classes and categories of entia. The theory of ideas is still not present in Parmenides, and although he establishes that ens is the truth and that the truth is found by reason and not by sensible appearances, he does not give evidence of knowledge of the doctrine of ideas. On the other hand, if we consider the philosophical systems which his own opposed, that is, the Ionian systems, we see that his interest lay in physical, natural things, whose falseness, and principally their continuous flux, he strove to demonstrate. This explains the second part of his poem (*), where indeed he explains the doctrine of material nature as it appears to the senses. Parmenides had in mind only physical things in order to show that they were and put the truth in their place.

This explains why Aristotle expounded Parmenides' teaching as if Parmenides wanted to indicate with his ens the principle of nature (Phys., 1: 2; Metaph., 1: 5). In fact Aristotle criticised Parmenides because, he said, Parmenides' system was not at all in keeping with nature. Thus Aristotle treated Parmenides, according to Bessarion, as he, that is, Aristotle had treated the Pythagoreans. Bessarion said: 'Aristotle applied to sensible things what the Pythagoreans had said about numbers and intelligible substances' (In Calumn., 2, 4). The truth is that Parmenides was content to explain the general theory of ens without applying it, but simply contenting himself with the insufficiency of knowledge of physical things. Then came Plato. Although he supported Parmenides' general doctrine of ens, he added that it was true only for ideal being, but allowed that passing things ('generable', as he called them, because they have no permanence) do not endure: they could be considered as non-entia, and consequently as blind and per se unintelligible. This application to ideas of Parmenides' theory of ens was Plato's great contribution to the system of this sublime Italian philosopher. The Neoplatonists did Plato an injustice by attributing the addition to Parmenides himself.