The discussion occupies two or three pages of Aristotle's Physica. In regard to [Greek: a)lloi/ôsis] or qualitative change, he recognised what he called [Greek: a)thro/an metabolê/n]--a change _all at once_, which occupied no portion of time. It is plain, however, that even his own scholars Theophrastus and Eudemus had great difficulty in accepting the doctrine; see Scholia, pp. 409-410-411, Brandis.] The two last Antinomies, or four last Demonstrations, have, in common, for their point of departure, the negative proposition, _Si Unum non est_: and are likewise put together in parallel couples (6-7, 8-9), a Demonstration and a Counter-Demonstration--a Both and a Neither: first with reference to the subject _Unum_--next with reference to the subject _Cætera_. [Side-note: Review of the two last Antinomies. Demonstrations VI. and VII.] _Si Unum est_--_Si Unum non est_. Even from such a proposition as the first of these, we might have thought it difficult to deduce any string of consequences--which Plato has already done: from such a proposition as the second, not merely difficult, but impossible. Nevertheless the ingenious dialectic of Plato accomplishes the task, and elicits from each proposition a Both, and a Neither, respecting several predicates of Unum as well as of Cætera. When you say _Unum non est_ (so argues the Platonic Parmenides in Demonstration 6), you deny existence respecting Unum: but the proposition _Unum non est_, is distinguishable from _Magnitudo non est_--_Parvitudo non est_--and such like: propositions wherein the subject is different, though the predicate is the same: so that _Unum non Ens_ is still a Something knowable, and distinguishable from other things--a logical subject of which various other predicates may be affirmed, though the predicate of existence cannot be affirmed.[96] It is both like and unlike, equal and unequal--like and equal to itself unlike and unequal to other things.[97] These its predicates being all true, are also real existences: so that Unum partakes _quodam modo_ in existence: though _Unum_ be _non-Ens_, nevertheless, _Unum non-Ens est_. Partaking thus both of non-existence and of existence, it changes: it both moves and is at rest: it is generated and destroyed, yet is also neither generated nor destroyed.[98] [Footnote 96: Plato, Parmenid. pp. 160-161 A. [Greek: ei)=nai me\n dê\ tô=| e(ni\ ou)ch oi(=o/n te, ei)/per ge mê\ e)/sti, mete/chein de\ pollô=n ou)de\n kôlu/ei, a)lla\ kai\ a)na/gkê, ei)/per to/ ge e(\n e)kei=no kai\ mê\ a)/llo mê\ e)/stin. ei) me/ntoi mê/te to\ e(\n mê/t' _e)kei=no_ mê\ e)/stai, a)lla\ peri\ a)/llou tou o( lo/gos, ou)de\ phthe/ggesthai dei= ou)de/n; ei) de\ to\ e(\n e)kei=no kai\ mê\ a)/llo u(pokei=tai mê\ ei)=nai, kai\ tou= _e)kei/nou_ kai\ a)/llôn pollô=n a)na/gkê au)tô=| metei=nai.]] [Footnote 97: Plato, Parmenid. p. 161 C-D.] [Footnote 98: Plato, Parmenid. pp. 162-163 A.