Certainly, in Demonstrations 1 and 2 (as well as 4 and 5), the foundation assumed is in words the same proposition--_Si Unum est_: but we shall find this same proposition used in two very different senses. In the first Demonstration, the proposition is equivalent to _Si Unum est Unum_:[72] in the second, to _Si Unum est Ens_, or _Si Unum existit_. In the first the proposition is identical and the verb _est_ serves only as copula: in the second, the verb _est_ is not merely a copula but implies Ens as a predicate, and affirms existence. We might have imagined that the identical proposition--_Unum est Unum_--since it really affirms nothing--would have been barren of all consequences: and so indeed it is barren of all affirmative consequences. But Plato obtains for it one first step in the way of negative predicates--_Si Unum est Unum, Unum non est Multa_: and from hence he proceeds, by a series of gentle transitions ingeniously managed, to many other negative predications respecting the subject _Unum_. Since it is not Multa, it can have no parts, nor can it be a whole: it has neither beginning, middle, nor end: it has no boundary, or it is boundless: it has no figure, it is neither straight nor circular: it has therefore no place, being neither in itself, nor in anything else: it is neither in motion nor at rest: it is neither the same with anything else, nor the same with itself:[73] it is neither different from any thing else, nor different from itself: it is neither like, nor unlike, to itself, nor to anything else: it is neither equal, nor unequal, to itself nor to any thing else: it is neither older nor younger, nor of equal age, either with itself or with anything else: it exists therefore not in time, nor has it any participation with time: it neither has been nor will be, nor is: it does not exist in any way: it does not even exist so as to be Unum: you can neither name it, nor reason upon it, nor know it, nor perceive it, nor opine about it. [Footnote 72: Plato, Parmenid. pp. 137 C, 142 B.] [Footnote 73: This part of the argument is the extreme of dialectic subtlety, p. 139 C-D-E.] [Side-note: First demonstration ends in an assemblage of negative conclusions. _Reductio ad Absurdum_, of the assumption--Unum non Multa.] All these are impossibilities (concludes Plato). We must therefore go back upon the fundamental principle from which we took our departure, in order to see whether we shall not obtain, on a second trial, any different result.[74] [Footnote 74: Plato, Parmenid. p. 142 A.]