Sec.32.  For this cf. D.F. IV. 8—­10. Notionibus:  so one MS. for motionibus which the rest have. Notio is Cicero’s regular translation for [Greek:  ennoia], which is Stoic.  This statement might have been made both by Aristotle and Plato, though each would put a separate meaning on the word notio. [Greek:  Episteme] in Plato is of the [Greek:  ideai] only, while in Aristotle it is [Greek:  ton katholou]; cf. Anal.  Post. I. 33 (R. and P. 264), [Greek:  lego noun archen epistemes]. Definitiones rerum:  these must be carefully distinguished fiom definitiones nominum, see the distinction drawn after Aristotle in R. and P. 265, note b.  The definitio rei really involves the whole of philosophy with Plato and Aristotle (one might almost add, with moderns too).  Its importance to Plato may be seen from the Politicus and Sophistes, to Aristotle from the passages quoted in R. and P. pp. 265, 271, whose notes will make the subject as clear as it can be made to any one who has not a knowledge of the whole of Aristotle’s philosophy. Verborum explicatio:  this is quite a different thing from those definitiones nominum just referred to; it is derivation, which does not necessitate definition. [Greek:  etymologian]:  this is almost entirely Stoic.  The word is foreign to the Classic Greek Prose, as are [Greek:  etymos] and all its derivatives. ([Greek:  Etymos] means “etymologically” in the De Mundo, which however is not Aristotle’s).  The word [Greek:  etymologia] is itself not frequent in the older Stoics, who use rather [Greek:  onomaton orthotes] (Diog.  Laert.  VII. 83), the title of their books on the subject preserved by Diog. is generally “[Greek:  peri ton etymologikon]” The systematic pursuit of etymology was not earlier than Chrysippus, when it became distinctive of the Stoic school, though Zeno and Cleanthes had given the first impulse (N.D. III. 63).  Specimens of Stoic etymology are given in N.D. II. and ridiculed in N.D. III. (cf. esp. 62 in enodandis nominibus quod miserandum sit laboratis). Post argumentis et quasi rerum notis ducibus:  the use of etymology in rhetoric in order to prove something about the thing denoted by the word is well illustrated in Topica 10, 35.  In this rhetorical sense Cic. rejects the translation veriloquium of [Greek:  etymologia] and adopts notatio, the rerum nota (Greek [Greek:  symbolon]) being the name so explained (Top. 35).  Varro translated [Greek:  etymologia] by originatio (Quintil.  I. 6, 28).  Aristotle had already laid down rules for this rhetorical use of etymology, and Plato also incidentally adopts it, so it may speciously be said to belong to the old Academico-Peripatetic school.  A closer examination of authorities would have led Halm to retract his bad em. notationibus for notas ducibus, the word notatio