I would call your attention to the distinction between sense and reason, which appears to be more distinctly announced in his system than in any other that had preceded. I am not aware that he calls λόγος or reason the faculty of truth for all, and δόξα or αἴσθησις the faculty of truth for some; but this is evidently his meaning, this was the substance of his distinction between λόγος and αἴσθησις; the latter he did not consider to be properly the organ of truth at all, but only the former. The main points of detail in the system are these: First, Being is the universal, the element in which all things agree. This is apprehended by reason. Secondly, The particular or non-universal in things is not-Being. This is apprehended by sense. Thirdly, No attempt is made to conciliate, but rather to separate absolutely, the members of this antithesis. This separation of the antithesis necessarily preceded the conciliation of the antithesis, otherwise there would have been no antithesis at all. Fourthly, The consequence is that the universe of Parmenides falls asunder into two contradictories, a world of unity on the one hand, where there is no diversity, and a world of diversity on the other hand, in which there is no unity. Fifthly, His attempt to save the material phenomena by attributing to not-Being a spurious Being (if indeed he does make this attempt) is altogether unsuccessful; for he has carried Being wholly over into the intelligible world, and therefore the sensible world, or the world of not-Being, cannot on his principles have any Being at all conceded to it.
