  It appears that all of the Arguments in D5 are valid. Like the Arguments of the first four Deductions, the Arguments of D5 rest on a number of independent premises, including premises of D1, D2, and the Appendix (but not D3 or D4). Again, it appears that most of the premises are, at least from Plato’s point of view, either definitionally true or self-evident. Thus it appears that, from Plato’s point of view, D5 establishes, without reliance on Purity-F or any other potentially problematic assumption, that if the one is not, then the one has a host of contrary properties. In other words, as Plato sees it, D5 establishes that if the one is not, then Purity-F is false.