  It appears that all of the Arguments in D8 are valid. Like the Arguments of the first seven Deductions, the Arguments of D8 rest on a number of independent premises, including premises of D1. Again, it appears that most of the premises are, at least from Plato’s point of view, either definitionally true or just plain obvious. Thus it appears that, from Plato’s point of view, D8 establishes, without reliance on Purity-F or any other potentially problematic assumption, that if the one is not, then the others are, at the very least, neither one nor many.