Editing Parmenides (section)

===Plato===
Along with [[Socrates]] and the [[Pythagoreans]], Parmenides was one of the greatest influences on Plato.{{sfn|Palmer|2020|loc=§3.4}}

In different places, Aristotle attributes the same epistemological position to Parmenides<ref>De Caelo 3.1</ref> that he does to Plato,<ref>Metaphysics 13.4</ref> that true knowledge must be grounded in an entity that is not subject to change.{{sfn|Palmer|2020|loc=§3.4}} This position is also endorsed by Plato himself at the end of the 5th book of the Republic.{{sfn|Palmer|2020|loc=§3.4}} For Plato, these are the forms from his own [[Theory of Forms]].{{sfn| Palmer| 2020| loc=§3.4}} In his own ''Parmenides'', Plato presents a fictional dialogue between Socrates and Parmenides where Parmenides himself also endorses this doctrine, that knowledge must be built on something unchanging.{{sfn| Palmer| 2020| loc=§3.4}}

Plato's understanding of Parmenides is further demonstrated by the second hypothesis in his ''Parmenides''<ref>Plato, Parmenides, 142b</ref> There, the One is shown to have different properties that parallel those laid about by Parmenides himself in Fragment 8: that the One is: in itself, the same as itself, at rest, like itself, and in contact with itself, both "in virtue of its own nature" and "in relation to itself."{{sfn| Palmer| 2020| loc=§3.4}} Plato then has Parmenides show that and that the One is ''not'' those same set of attributes, but only "contrary to its own nature" and "not in relation to itself," which parallels Parmenides own division of what is and what appears to be, that the "Way of Truth" corresponds to his own intelligible realm of forms, while the "Way of Opinion" corresponds to the sensible realm of matter.{{sfn| Palmer| 2020| loc=§3.4}} These two aspects of reality are also paralleled in Plato's ''Timaeus'' in the descriptions of the universe as a living creature perceived by reason and a cosmos modeled after it that is perceived by the senses.{{sfn| Palmer| 2020| loc=§3.4}} In the ''[[Sophist (dialogue)|the Sophist]]'', Plato gives a [[doxography]] of the Eleatics beginning not with Parmenides but with [[Xenophanes]], another pre-Socratic philosopher after whom Parmenides followed after, who believed true knowledge was only possible for the gods and that all else was opinion, which provides further support to the idea that Plato saw the monism of Parmenides as not eliminating the possibility of statements about the "Way of Opinion."

==== Aristotle ====
Aristotle, in his ''Physics'',<ref>Physics 1.8, 191a</ref> makes reference to unnamed philosophers who reject substantial change because they hold the view that no entity or substance comes into being, which superfically appears to resemble Parmenides own doctrine.{{sfn|Palmer|2020|loc=§3.4}} However, he cannot be referring to Parmenides here, because in other places<ref>Aristotle, On the Heavens 3.1 298b; Metaphysics 1.5 986b; Physics 1.2 184ab</ref> he distinguishes between Parmenides' account of "first philosophy" which is not subject to change, and Parmenides' account of natural philosophy, in which he admits the possibility of substantial change.{{sfn|Palmer|2020|loc=§3.4}} When Aristotle introduces Parmenides own doctrines in the ''Physics'',<ref>Physics 1.2-1.3</ref> alongside those of another Eleatic philosopher, [[Melissus of Samos]], he distinguishes between the more strict monism of Melissus, which held that there can only be one substance that exists, and Parmenides' more permissive monism, which considered everything that exists to be substance in virtue of the fact that it exists, but allowed for different substances to exist.{{sfn|Palmer|2020|loc=§3.4}}

==== Hellenistic and Roman philosophy ====
Some Ancient philosophers did view Parmenides as a strict monist like Melissus, though they represented a minority opinion.{{sfn|Palmer|2020|loc=§3.4}} Writing in the late 1st century CE, the [[Middle Platonist]] philosopher [[Plutarch]], in his treatise ''Against Colotes'' attributes this position to [[Colotes]], an [[Epicureanism|Epicurean]] philosopher from the Hellenistic period.{{sfn|Palmer|2020|loc=§3.4}} Plutarch, who like many Platonists saw Parmenides as a forerunner of Plato,{{sfn|Palmer|2020|loc=§3.4}} criticizes Colotes for misrepresenting Parmenides' position, stating that Parmenides distinction between what truly is and what things appear to be according to the senses should not be seen as a rejection of the latter, because, as Plutarch argues, one could not do that without rejecting the existence of the senses themselves.{{sfn|Palmer|2020|loc=§3.4}}

[[Eusebius of Caesarea]], quoting [[Aristocles of Messene]], says that Parmenides was part of a line of skeptical philosophy that culminated in [[Pyrrhonism]].<ref>[[Eusebius]], ''[[Praeparatio Evangelica]]'' [https://www.tertullian.org/fathers/eusebius_pe_14_book14.htm Book XIV], Chapter XVII</ref>{{primary source inline|date=May 2025}}

For Simplicus, a [[Neoplatonist]] philosopher writing in the 6th century, who preserves almost the entirety of our extant fragments of the treatise, the two accounts describes by the goddess in Parmenides poem correspond to two different levels of reality: the intelligible and eternal realm of forms, and the constantly changing sensible world.<ref>Simplicius, Commentary on Aristole's On the Heavens</ref>{{sfn|Palmer|2020|loc=§3.4}}