12. That which is capable of moving things but does not actually do so will not account for motion. It is no use positing eternal sub- stances (e.g. Forms) if we do not give them a principle of change. Nor will it do if the principle is active but its essence is potentiality,
368 Commentary
for then motion will not be eternal. Therefore there must be a prin- ciple whose being is actuality. And these substances must be without matter, for they must be eternal. Therefore they are actuality.
22. There is a difficulty. Everything actual has potentiality but not everything that is potential has actuality, so that potentiality seems prior. But if this were so, all that is might not be (i.e. not yet have been).
26. The same difficulty is involved if the world be generated from night or from ‘all things together’. Matter cannot set itself in motion. Hence Leucippus and Plato say there is always motion—but do not specify it or its cause, or the cause of the motion’s being of the parti- cular kind it is. Nothing is moved at random; everything has its own proper motion, and its motion under compulsion, etc. Further, what kind of motion is first? Further, Plato could not tell what he means by describing the self-moving as a first principle, for the soul is later— coeval with the heavens. It is in a sense right to take potentiality as prior to actuality, but in another sense wrong. Anaxagoras testifies that actuality is first; so do Empedocles and Leucippus.
1072" 7. Therefore chaos or night did not last an indefinite time. The same things existed always either in a cycle or in some other way, for actuality is prior to potentiality. If there is cyc#c change, something must remain always active in the same way. If there is to be change at all, there must be something else whose activity varies. This must act in one way fer se, in another way by virtue of something else, and this something else must be that which acts always in the same way. This is the cause of uniformity, the other the cause of variety, both together the cause of uniform variety. Accordingly these are the movements that actually exist. What need, then, to seek other principles?
1071 3. Haar, cf. 1069% 30.
5. ai Te yap odciat mpdtat ty dvtwy. Aristotle has tried to prove this in 1069* 19-26.
6-10. GAN’ a8dvarov . . . mdfos. The argument is: If all sub- stances are perishable, everything else is perishable (since everything else is posterior to and depends on substance). But movement and time are not perishable. Therefore not all substances are perishable.
For the eternity of movement cf. Phys. viii. 1-3.
8. od yap... xpdvov. The argument is: If you say time comes into being, you imply that before that there was no time; but the very word ‘before’ implies time. But does not Aristotle’s view that space is finite contain the same difficulty ?
9. Having used the eternity of movement to prove that there must be an eternal substance, Aristotle now draws from it a further y inference, that movement must be continuous, and from this he
develops his whole astronomical theory.
10. 7 Kwyoeds Tt mdOos, cf. Phys. 251% 28. In Phys. 219 1 time is defined more precisely as dpiO ds Kivypoews Kata TO mpdrepov Kal Vorrepov. It is further said to be dpiOpos ody & apiOpodpev GAN 6 apiOpovpevos (220 8), i.e. not abstract number, but the aspect in respect of which movement is numerable.
IO-II. kivnows 8... kUkAw. Aristotle’s proof that local movement is the only change that can be continuous is given in Phys. 261% 31— 26, and his proof that circular. movement is the only one that can be con- tinuous in 261» 247—26323, 26427—265212. The reason for the first dictum is that all other changes are between opposites, and that, since a thing cannot have opposite movements at the same time, it must rest at the opposites which form the limits of its move- ment. The reason for the second dictum is that all other changes of place are from opposite to opposite, and therefore (like non-local changes) cannot be continuous.
- 13. obK €otau Kivyars, ‘there need not be (always) movement’, For this use of the future cf. Bz. Zndex 754” 5-12.
15. ei py tis Suvapévy evéotar dpxy peraBdddew. Aristotle has argued in A. 988? 2 that there is no such dpyy in the Ideas.
16. 008 GAA ovata mapa Ta eidy, e.g. the mathematical objects which Plato supposes to be independent substances, Z. 102820. Robin suggests that the reference is to the Platonic world-soul (cf. 1072 r). But, since this is thought of as essentially active, the objection « ji evepyynoel, ovk eorar kivnois would not be appropriate to it.
19-20. Rolfes remarks that the description of God as pure actuality is inconsistent with any form of pantheism, which at once involves God in development. Aristotle’s remarks on Speusippus and the Pythagoreans (1072) 31) show how clearly he saw the irreconcilability of pure actuality with development.
21. tavtas . .. Tas ovcias., So far Aristotle has spoken of the necessity of one unmoved mover of the universe. He now refers by anticipation to the unmoved movers of the several celestial spheres, for which cf. 10742 15.
22. From Alexander 689. 19 it seems clear that he read, with Ab, évepyeta, which is the preferable reading.
24. ote Tpdtepoy etvar thy Suvapi, on the principle stated in A. 1019*2 7d 8 Kara piow Kal odciav (porepa), doa evdexerar elvar avev dAdo, exelva & dvev éxeivwv pun.
25. o00év eora tv dvrwy, ‘nothing that is need be’, cf. ovk éorau kivnots, 1. 13. That there never was a time when there was nothing, is proved in De Caelo i. 12.
26. «i ds Aéyouow = ci ovrws exes Ws Aéyovow. For this use of ds cf. De Gen. et Corr. 329% 35 Tatra pev yap petaBdAde eis dAXyAG, Kal ovx os *Eprredox) fs Kal €repou Aéyovow.
370 Commentary
27. ot Oeoddyor, cf, A. 983) 29 n.
ot ék vuktos yevvavtes, cf..N. togi5, and Orpheus fr. 12 Diels, Musaeus fr. 14, Epimenides fr. 5, Acusilaus fr. 1, 3, Hesiod, Op. e¢ D. nF Theog. 116 ff., Aristoph. Av. 693.
ol duotkot, i.e. in particular Anaxagoras, fr, 1, but his view is in this respect like those of Anaximander, Empedocles, Democritus, and others ; cf. 1069? 20-23.
30. o88€ TA Eripyvia 068’ 7 yh, GAAG TA orréppata Kal H yovy, i.e. yovn is needed to transform the émiyvia, which are potentially the young animal, into the actual offspring, while oépyara are needed to transform the earth, which is potentially the young plant, into the actual plant. -yovy is properly used only of the male element in the sexual generation of animals (G. A. 724? 12), while owépyara may be used with reference to plants as well, which have not the distinction of male and female (715” 19, 731” 10), but have something akin to it (715” 20, 732° 12), though the two elements are united in the same plant (731° 1, 200 28, 741" 3, TBO? 30, 763” 24).
ZI. 81d eviot movotow det evépyerav, otoy AevKurmos. Cf. De Caelo 300? 8,
32. Kal MAdtwy, cf. 77m. 304.
33. GANA Bid TL Kal tiva od héyouow. Cf. A. 985” 19, De Caelo 300? ro, 16, and (on Democritus) 313% 21. The objection is not fair, as regards Plato; he makes the world-soul the cause of the movement, cf, 107271.
34. Diels’s reading, o08, ei Ot 7 G8, is much the best emendation of the unmeaning ovdé ddt odd¢ Of the manuscripts, and derives sup- port from Alexander 690. 35. Schwegler’s ovdé rod &d/ and Zeller’s ovd «i woi are less probable.
35. Prof. Jackson thinks that the readings of A (de? aied 7) and of E (de? 7 dei) point to an original de? 7 dia ri. But the two readings are merely an instance of the constant tendency of the two manuscript groups to vary the order of words, and the required sense ‘there must be a cause’ may be got out of the traditional reading. ‘There must in every case be something present’, sc. to account for the particular movement. The simplest emendation would be de? rw’ (sc. airiav) del id pew.
36. 4 . 7 Alexander takes to mean ‘either... or’, Themistius (probably rightly) to mean ‘or... or’
&AXou, e.g. THS pavracias (Alexander).
1072°1. dpxny, Sc. Kujoews.
2. Uotepov, sc. THs KWHoEws, NOt Tod otpavod as Bz. supposes. Aristotle seems to be reasoning from the late point at which the formation of the soul appears in the Zimaeus (348). He argues that Plato makes soul coeval with the heavens, which are later than the original disordered movement of Z?m. 30, and that soul therefore cannot be the cause of this movement. Plato no doubt describes the soul as the principle of all movement and as eternal (Phaedr. 245 c—246 A, cf. Laws 894 c—896r). Further, he describes
it aS Kal yevéres kal dperh mporépay Kal mpeoBurépay Toparos (Zim. 34C), and explains that it is only in the order of his exposition that it is later (348). But he at any rate describes it as made by God (34 c), while movement is found by God as something pre-existing (30 a). Some- thing must be allowed for the mythical and conjectural character of the Timaeus, but it does not seem that, as Zeller maintains in Pla/onische Studien, Plato had a perfectly consistent theory.
4. elpntar 8é ms. It is not very clear whether this refers to 1071» 22-26 or to @. 8. Bz. contends that when Aristotle refers in one book of the AZefaphysics to another, the reference is always fuller in form than this. H. 104243 and N, 1090%15 hardly form exceptions to this rule, since ZH and MN so clearly belong together respectively. The only genuine exception is K. 1064236, which seems to refer to A. 6, 7. In the other works the only instances I have noted of very vague references in one work to another are De Gen. ef Corr. 33615, De Caelo 271% 21, De Resp. 47712, De Sensu 436% 1, G. A. 715%1. On the whole Bz. seems justified in inferring that the refer- ence here is to 1071 22-26. That passage does not definitely say in what sense potency and in what sense actuality is prior, but indicates obscurely that though each individual potency is prior to the corresponding actuality, there must be some actuality prior to all potency.
5. Alexander seems to have read évépyeva (691. 33), and so do TT Ald. This reading is preferable to that of EJA?.
6. “Epmedoxdijs pudiav kal 1d veikos, sc. A¢ywv from Adyovres. For the arbitrary insertion of 7d cf. the passages referred to by Vahlen on Poet. 1449%1—®. 1049? 11, M. 10819 34, Soph. LV. 173° 9, De Resp. 478) 28, Rhet. 1361% 24, 1363” 3, 13695, 1390716, 14047) 31, 1414° ER.
ot del Aéyovres kivnow evar, cf. 1071) 32,
8. TadTd del 7 Tepiddw 7 Ans: tepid refers to Empedocles’ doc- trine of cycles (De Caelo 279” 14, Phys. 250 26). dAdws refers to any view which, without committing itself to cycles, holds that the main characteristics of the universe remain the same. In the next sentence Aristotle concentrates on the belief in cycles, though what he says of ils implications would apply also to the alternative view referred to in dAAws. It is not necessary with Schwegler to treat repiddw in 1. 10 as a gloss.
9-17. The general upshot of this passage is that the motion of the sphere of the fixed stars, which is parallel to the equator and therefore unchanging relatively to the earth, is the cause of the permanence in the history of the world, while the ecliptic motion of the sun, which brings it now nearer to and now farther from us, causes the alternation of birth and death. Cf. 1071%15, De Gen. ef Corr. 336” 15.
IO. Set te det pever doadtws evepyody, From De Gen. et Corr. 336 23 ff. it is clear that the reference is to the sphere of the fixed stars, while the évepyodv GAAws Kat adAws is the sun, which moves in one way (éd¢)—i.e. has its yearly motion along the ecliptic— xa aird, and
Bb2
372 Commentary
moves in another way—i.e. has its daily motion parallel to the equator —kxatr dAdo. The question then arises whether this dAdo is 76 rpGror, i.e. the sphere of the fixed stars, or something else’ (e. g. the sphere of - Saturn, says Alexander). But if we suppose something else to be the cause, then in turn the sphere of the~fixéd. stars causes both the sun’s motion and that of the supposed other.