imperishable (cf. Tim. 52 A. [Greek:  phthoran ou prosdechomenon]). Non in nihilum:  this is aimed at the Atomists, who maintained that infinite subdivision logically led to the passing of things into nothing and their reparation out of nothing again.  See Lucr.  I. 215—­264, and elsewhere. Infinite secari:  through the authority of Aristotle, the doctrine of the infinite subdivisibility of matter had become so thoroughly the orthodox one that the Atom was scouted as a silly absurdity.  Cf. D.F. I. 20 ne illud quidem physici credere esse minimum, Arist. Physica, I. 1 [Greek:  ouk estin elachiston megethos].  The history of ancient opinion on this subject is important, but does not lie close enough to our author for comment.  The student should at least learn Plato’s opinions from Tim. 35 A sq.  It is notable that Xenocrates, tripping over the old [Greek:  antiphasis] of the One and the Many, denied [Greek:  pan megethos diaireton einai kai meros echein] (R. and P. 245).  Chrysippus followed Aristotle very closely (R. and P. 377, 378). Intervallis moveri:  this is the theory of motion without void which Lucr.  I. 370 sq. disproves, where see Munro.  Cf. also Sext.  Emp. Adv.  Math. VII. 214.  Aristotle denied the existence of void either within or without the universe, Strato allowed its possibility within, while denying its existence without (Stob.  I. 18, 1), the Stoics did the exact opposite affirming its existence without, and denying it within the universe (Zeller 186, with footnotes). Quae intervalla ... possint:  there is no ultimate space atom, just as there is no matter atom.  As regards space, the Stoics and Antiochus closely followed Aristotle, whose ideas may be gathered from R. and P. 288, 9, and especially from M. Saint Hilaire’s explanation of the Physica.

Sec.28. Ultro citroque:  this is the common reading, but I doubt its correctness.  MSS. have ultro introque, whence ed.  Rom. (1471) has ultro in utroque.  I think that in utroque, simply, was the reading, and that ultro is a dittographia from utro.  The meaning would be “since force plays this part in the compound,” utroque being as in 24 for eo quod ex utroque fit.  If the vulg. is kept, translate “since force has this motion and is ever thus on the move.” Ultro citroque is an odd expression to apply to universal Force, Cic. would have qualified it with a quasi.  Indeed if it is kept I suggest quasi for cum sic.  The use of versetur is also strange. E quibus in omni natura:  most edd. since Dav. (Halm included) eject in.  It is perfectly sound if natura be taken as [Greek:  ousia] = existence substance.  The meaning is “out of which qualia, themselves existing in (being co-extensive with) universal substance (cf. totam commutari above), which is coherent and continuous,