Authors/Thomas Aquinas/metaphysics/liber12/lect6

Lecture 6

Latin	English
lib. 12 l. 6 n. 1 Movet quamdam dubitationem circa praedeterminata. Et est dubitatio, utrum actus sit simpliciter prior potentia, ut possit poni primum principium rerum esse tale, cuius substantia sit actus. Et circa hoc tria facit. Primo ponit rationem ad ostendendum falsum, scilicet quod potentia sit prior actu. Secundo ponit rationem in contrarium, ibi, at vero si hoc, nihil erit. Tertio solvit dubitationem, ibi, potentiam quidem igitur. Dicit ergo primo, quod dictum est, quod substantia sempiterna est actus, quamvis de hoc sit dubitatio. Videtur enim potentia simpliciter esse prior actu: nam prius est a quo non convertitur consequentia essendi. Hoc autem modo videtur potentia se habere ad actum: quia omne agens videtur posse agere, sed non omne quod potest agere agit; quare videtur quod potentia sit prior actu.	2500. He raises a question about a point already dealt with. The question is whether actuality is prior absolutely to potentiality so that the first principle of things can be held to be one whose substance is actuality. In regard to this he does three things. First (1059)C 2500), he gives an argument to show what is false, namely, that potentiality is prior absolutely to actuality. Second (1060:C 2501), he argues on the other side of the question (“But if this is so”). Third (1062:C 25o6), he answers the question (“Now to think”). He accordingly says, first (1059), that it has been pointed out that an eternal substance is an actuality, although there is a difficulty regarding this. For potentiality seems to be prior to actuality, since one thing is prior to another when the sequence of their being cannot be reversed (465:C 950)Now potentiality seems to be related to actuality in this way, because everything which is acting seems to be able to act, but not everything which is able to act is acting; and so it seems that potentiality is prior to actuality.
lib. 12 l. 6 n. 2 Deinde cum dicit at vero si ponit rationem in contrarium. Et circa hoc duo facit. Primo ponit rationem ducentem ad impossibile: dicens, quod si potentia sit simpliciter prior actu, sequitur quod aliquando nihil sit: contingens est enim id quod potest fieri, sed nondum fit. Et ita, si prima entia sunt in potentia, sequitur quod non sunt actu: et sic nihil aliorum erit.	2501. But if this is so (1060). Then he argues on the opposite side of the question, and in regard to this he does two things. First, he gives an argument reducing the counter-position to absurdity. He says that, if potentiality is prior absolutely to actuality, it follows that at some time nothing may exist; for the contingent is what can come to be but has not yet done so. Hence, if the first beings are potential, it follows that they do not exist actually; and so no other being will exist.
lib. 12 l. 6 n. 3 Et hoc quidem contingit dupliciter. Uno modo secundum opinionem quorumdam antiquorum, qui vocabantur poetae theologi, sicut fuit Orpheus, et quidam alii, qui ponebant mundum esse generatum ex nocte, idest simplici privatione praeexistente. Alio modo secundum posteriores naturales, sicut physici naturales, et eos sequentes, qui cum viderent quod secundum naturam nihil fit ex nihilo, posuerunt omnia esse simul in quadam confusione, quam vocabant chaos, sicut posuit Anaxagoras: et sic ponebant omnia esse in potentia, non autem in actu.	2502. This can be taken in two ways. First, according to the opinion of certain of the ancients, who were called the theological poets, such as Orpheus and certain others, who claimed that the world “is generated from Night,” i.e., from a simple pre-existent privation. Second, according to the later physicists, i.e., philosophers of nature and their followers, who, when they saw that nothing comes from nothing in the natural world, claimed that all things were together in a kind of mixture, which they called Chaos. (Anaxagoras, for example, held this view.) Thus they held that all things exist potentially and not actually.
lib. 12 l. 6 n. 4 Sed, sive hoc modo, sive illo dicatur, sequitur idem impossibile, si potentia simpliciter sit prior actu. Illa enim quae sunt in potentia tantum, sive sint omnino sub privatione, sive sint in quadam confusione, non poterunt moveri, ut reducantur in actum, nisi sit aliqua causa movens in actu existens; quia materia in artificialibus non movet seipsam, sed ipsam movet agens, scilicet tectonica, idest ars. Nec menstrua, quae sunt materia in generatione animalis, movent seipsa, sed movet ea genitura, idest semen animalis. Nec terra, quae est materia in generatione plantarum, movet seipsam, sed movent eam spermata, idest semina plantarum.	2503. But whether this position is stated in the former or in the latter way the same impossible conclusion follows, provided that potentiality is prior absolutely to actuality. For those things which are in potentiality only, or which come entirely under privation, or belong to some confused mass, cannot be moved so as to be brought to actuality unless there is some moving cause which is existing actually. For in things made by art the matter does not move itself, but an agent moves it, i.e., “technical knowledge,” or art. Neither does the menstrual blood, which is the matter from which an animal is generated, move itself, but “semen,” i.e., the sperm of the animal, moves it. Nor does earth, which is the material from which plants are generated, move itself, but “the seed,” i.e., the seeds of plants, move it.
lib. 12 l. 6 n. 5 Secundo ibi, propter quod ostendit quomodo huic rationi quidam physici consenserunt. Dicit ergo, quod propter hanc rationem quidam philosophi posuerunt semper actum existentem, scilicet Leucippus socius Democriti, et Plato. Dixerunt enim motum semper fuisse etiam ante mundum. Secundum quidem Leucippum in atomis per se mobilibus, ex quibus ponebat mundum constitui. Secundum Platonem vero in elementis, quae dicebat ante constitutionem mundi mota fuisse motibus inordinatis, sed postea a Deo fuisse ea reducta ad ordinem.	2504. This is the reason (1061). Second, he shows how some of the philosophers of nature agreed with this argument. He says that this is the reason why some philosophers—Leucippus, the companion of Democritus, and Plato—claimed that something actual always exists. For they said that motion had always existed even before the world; Leucippus attributed motion to the atoms, which are mobile of themselves, from which he supposed the world to be composed; and Plato attributed it to the elements, which he said were moved by disorderly motions before the formation of the world, and afterwards were brought into order by God.
lib. 12 l. 6 n. 6 Sic igitur quantum ad hoc videntur bene dixisse, quod posuerunt semper fuisse motum. Sed in hoc defecerunt, quia non dixerunt quis motus semper fuerit, nec causam motus assignaverunt, nec simpliciter narrando, nec suae positionis causam assignando, cum tamen nihil moveatur ut contingit, idest sine aliqua causa certa. Sed semper oportet aliquid existere, quod est causa motus. Sicut nunc videmus, quod quaedam moventur hoc modo a natura, aut a violentia, aut ab intellectu, aut aliqua alia causa. Deinde debuerunt etiam assignare, qualis sit prima causa motus, utrum natura, sive violentia, sive intellectus; multum enim differt quodcumque horum ponatur causa motus. Sed nec Plato potest excusari, propter hoc, quod posuit principium motus esse aliquid movens seipsum, quod dicebat esse animam: sed anima secundum ipsum non fuit ante constitutionem mundi, sed fuit post illam inordinationem motus. Fuit enim facta simul cum caelo, quod ponebat animatum. Et sic anima non poterit esse principium illius motus inordinati.	2505. Now they seem to be right in claiming that motion has always existed. But they were wrong in failing to point out which kind of motion has always existed; nor did they give the cause of motion, either by stating this in an absolute sense or by giving the reason for their own position. Yet “nothing is moved by chance,” i.e., without some fixed cause, but there must always be something existing which is the cause of motion. For example, we now see that some things are moved in this way by nature or by force or by mind or by some other agent. Hence they should also have stated what the first cause of motion is, whether nature or force or mind; for it makes a great deal of difference which of these is held to be the cause of motion.—Plato cannot be excused on the ground that he held the principle of motion to be something that moves itself, which he asserted to be a soul, since the soul did not exist of itself before the formation of the world, but only existed after the disorderly state of motion. For according to him the soul was created at the same time as the heavens, which he claimed to be animated; and thus it could not be the principle of that disorderly motion.
lib. 12 l. 6 n. 7 Deinde cum dicit potentiam quidem solvit propositam quaestionem. Et circa hoc duo facit. Primo remittit ad hoc quod determinatum est in nono de ordine potentiae ad actum; dicens, quod opinari potentiam esse priorem actu, quodam modo bene dicitur, et quodam modo non. Et quomodo hoc sit, dictum est in nono. Ibi enim dictum est, quod actus simpliciter est prior potentia; sed in uno eodem quod movetur de potentia in actum, potentia praecedit actum tempore, quamvis actus sit prior natura et perfectione.	2506. Now to think (1062). Then he answers the question which was raised, and concerning this he does two things. First, he returns to the points established in Book IX regarding the relationship of potentiality to actuality. He says that the opinion that potentiality is prior to actuality is in one sense right and in another not. The sense in which it is right has been explained in Book IX (778-80:C 1844-49); for it was stated there that actuality is prior absolutely to potentiality. But in one and the same subject which is being moved from potentiality to actuality, potentiality is prior to actuality in time, although actuality is prior both in nature and in perfection.
lib. 12 l. 6 n. 8 Secundo ibi, quod autem confirmat solutionem per positiones quorumdam philosophorum; dicens, quod hoc quod actus sit simpliciter prior, testatur Anaxagoras, quia posuit primum principium movens esse intellectum. Intellectus enim actus quidam est. Et etiam Empedocles, qui posuit causas moventes litem et amicitiam. Et Leucippus et Plato, qui posuerunt semper motum fuisse.	2507. That actuality is prior (1063). Second, he strengthens his answer by giving the opinions of some of the philosophers. He says that the absolute priority of actuality is asserted by Anaxagoras, because he claimed that the first principle of motion is an intellect; for intellect is a kind of actuality. The same thing is also asserted by Empedocles, who claimed that love and strife are the causes of motion; and also by Leucippus and Plato, who claimed that motion has always existed.
lib. 12 l. 6 n. 9 Deinde cum dicit quare non ex determinatione quaestionis praemissae manifestat quod prius ostensum est. Et circa hoc tria facit. Primo concludit ex praemissis perpetuitatem generationis. Secundo ex perpetuitate generationis concludit perpetuitatem motus caeli, ibi, si itaque quidem semper. Tertio ex perpetuitate motus caeli concludit perpetuitatem primi moventis immobilis, ibi, est igitur aliquid et quod movet. Dicit ergo primo, quod si actus simpliciter est prior potentia, sequitur, quod falsa sit opinio antiquorum naturalium, qui existimantes potentiam simpliciter esse actu priorem, posuerunt omnia in infinito tempore prius fuisse in potentia, in quadam confusione, quam appellabant chaos. Falsa etiam erit opinio poetarum theologorum, qui propter eamdem existimationem posuerunt infinito tempore prius fuisse simplicem rerum privationem quam res actu esse inciperent. Quam quidem rerum privationem noctem appellabant, propterea forte, quia inter qualitates et formas sensibiles, lux communior et prior invenitur, cum ipsi nihil praeter sensibilia esse arbitrentur. Privatio autem lucis nox est. Utraque igitur opinio falsa est, si actus est prior potentia.	2508. Hence Chaos or Night (1064). Then he uses the answer to the question given above to clarify a point previously established, and in regard to this he does three things. First (1064:C 2508), in the light of the things established above he concludes that generation must be eternal. Second (1065:C 2510), on the ground that generation is eternal he concludes that the motion of the heavens must be eternal (“Therefore, if something”). Third (1066:C 2517), on the ground that the motion of the heavens is eternal he concludes that the first unmoved mover must be eternal (“Therefore there is”). He accordingly says, first (1064), that, if actuality is prior absolutely to potentiality, it follows that it is false to hold, with the ancient philosophers of nature, who thought potentiality to be prior absolutely to actuality, that all things pre-existed potentially for an infinite time in a kind of confused mass, which they called Chaos. And false also is the opinion of the theological poets, who claimed for the same reason that the simple privation of things had existed for an infinite time before things began to be actually. Some called this privation of things “Night,” and perhaps the reason for their doing so is that among qualities and simple forms light is found to be more common and prior (since they thought that nothing exists except sensible things), and night is the privation of light. Both opinions are false, then, if actuality is prior to potentiality.
lib. 12 l. 6 n. 10 Sed cum videamus ea quae generantur, de potentia ad actum procedere, necesse erit dicere, quod eadem quae actu esse incipiunt post potentiam, semper fuerunt aliquo modo,- vel secundum circularem generationem, prout ponuntur ea quae generantur, prius fuisse eadem non secundum numerum, sed secundum speciem, quod quidem fuit secundum circularem generationem. Nam ex terra humectata resolvuntur vapores, ex quibus generatur pluvia, per quam iterum humectatur terra. Similiter ab homine procedit sperma, et generatur iterum homo; et sic ea quae fiunt reiterantur eadem specie propter circularem generationem. Aut etiam ea quae post potentiam fiunt in actu, eadem fuerunt semper aliter, sicut posuit Anaxagoras quod praeextiterunt actu in his ex quibus generantur.	2509. But since we see that things which are generated and destroyed pass from potentiality to actuality, it will be necessary to say that the same things which begin to be actually after being potentially have always existed in some way. Either the very things which begin to be actually after being potentially have always existed according to circular generation, inasmuch as they claimed that things which are generated were formerly the same specifically but not numerically, and this is what occurs 2 in circular generation. For from the moist earth vapors are derived, and these turn into rain, by which the earth is again made moist. Similarly sperm comes from a man, and from sperm a man again comes to be. Thus things which come to be are brought back the same in species by reason of circular generation. Or again those things which come to be actually after being potentially have always been the same things in a different way, as Anaxagoras claimed that they had actual prior existence in the things from which they are generated.
lib. 12 l. 6 n. 11 Deinde cum dicit si itaque ex perpetuitate generationis concludit perpetuitatem motus caelestis. Supposito igitur, quod non sit aliquis alius motus, quo ea quae procedunt de potentia ad actum, semper eadem fuerint, nisi secundum circuitum generationis, ex his quae in scientia naturali ostensa sunt, et praecipue in secundo de generatione, concludit, quod si aliquid permanet idem per circuitum generationis, oportet et aliquid semper manere idem numero, quod similiter agat ad hoc, quod causet perpetuitatem: non enim potest esse causa perpetuitatis quae invenitur in generatione et corruptione, aliquid unum eorum quae generantur et corrumpuntur, quia nullum eorum semper est, neque etiam omnia, cum non simul sint, ut ostensum est in octavo physicorum. Relinquitur igitur, quod oportet aliquid esse perpetuum agens, quod semper uniformiter agat ad perpetuitatem causandam. Et hoc est primum caelum, quod movetur et resolvit omnia motu diurno.	2510. Therefore, if something (1065). Then he concludes that the motion of the celestial bodies must be eternal on the ground that generation is eternal. Therefore, granted that there is no other motion by which things that pass from potentiality to actuality have always been the same except that which proceeds according to the cycle of generation, he concludes from what has been shown in the philosophy of nature (especially in Book II of Generation ) that, if something remains the same throughout the cycle of generation, something must also remain numerically the same, which will act in the same way so as to cause the eternal motion of things. For none of the things which are generated and destroyed can be the cause of the eternality which is found in generation and destruction, because no one of them always exists, nor even all of them, since they do not exist at the same time, as has been shown in Book VIII of the Physics. It follows, then, that there must be some eternal, agent which always acts in a uniform way so as to cause the eternal motion of things. This is the first heaven, which is moved and causes all things to be changed by its daily motion.
lib. 12 l. 6 n. 12 Sed quia illud, quod semper eodem modo operatur, non causat nisi aliquod semper eodem modo se habens; in his autem quae generantur et corrumpuntur, apparet quod non semper se habent eodem modo, quia quandoque generantur, et quandoque corrumpuntur; si ergo debet esse generatio et corruptio in istis inferioribus, necesse est ponere aliquod agens, quod aliter se habeat in agendo: et hoc quidem agens dicit esse corpus quod movetur secundum circulum obliquum, qui dicitur zodiacus. Quia, cum hic circulus declinat ad utramque partem ab aequinoctiali, illud, quod movetur secundum circulum per zodiacum, oportet quod sit quandoque magis propinquum et quandoque magis remotum: et secundum hoc sua propinquitate et remotione causat contraria. Videmus enim quod ea, quae appropinquante sole ad nos, generantur, recedente sole, corrumpuntur. Sicut herbae, quae in vere nascuntur, et in autumno siccantur. Moventur enim in circulo zodiaco et sol et alii planetae. Sed et stellae fixae dicuntur moveri super polos zodiaci, et non super polos aequinoctiales, ut Ptolomaeus probat. Ex harum autem motu causatur generatio et corruptio omnium quae generantur et corrumpuntur, sed magis evidenter ex motu solis.	2511. But that which always acts in the same way only causes something that is always in the same state; and obviously those things which ~re generated and destroyed do not remain in the same state, for at one time they are generated and at another destroyed. This being so, if generation and destruction are to occur in the realm of lower bodies, it is necessary to posit some agent which is always in different states when it acts. He says that this agent is the body [the sun] which is moved in the oblique circle called the zodiac. For since this circle falls away on either side of the equinoctial circle, the body which is moved circularly through the zodiac must be at one time nearer and at another farther away; and by reason of its being near or far away it causes contraries. For we see that those things which are generated when the sun comes closer to the earth are destroyed when the sun recedes (for example, plants are born in the spring and wither away in the autumn); for both the sun and the other planets are moved in the circle of the zodiac. But the fixed stars are also said to be moved over the poles of the zodiac and not over the equinoctial poles, as Ptolemy proved. And the coming to be and ceasing to be of everything which is generated and destroyed is caused by the motion of these stars, but more evidently by the motion of the sun.
lib. 12 l. 6 n. 13 Hoc ergo movens quod aliter agit, necesse est quod quodam modo agat secundum se, idest ex propria virtute, inquantum causat diversitatem generationis et corruptionis; quodam vero modo secundum aliud idest ex virtute alterius, inquantum causat perpetuam generationem et corruptionem. Aut ergo oportet quod agat secundum aliquid alterum, idest virtute alicuius alterius, aut secundum primum, idest virtute primi, quod semper similiter agit. Et cum non sit aliquod alterum assignare, ex cuius virtute causet perpetuitatem, necesse est quod secundum hoc quod similiter agit, idest virtute eius, perpetuitatem generationis et corruptionis causet. Id enim, scilicet primum quod semper similiter agit, est causa ipsi, quod aliter et aliter agit: quia id quod aliter et aliter agit, perpetuo agit: id vero quod semper similiter agit, est causa perpetuitatis cuiuslibet motus: sic igitur est causa perpetuitatis eius, quod agit aliter et aliter, ut scilicet perpetuo sic agat; et illi etiam, quod ex eo causatur, scilicet generationi et corruptioni perpetuae. Ex quo patet, quod secundum agens, scilicet quod aliter et aliter agit, agit in virtute primi agentis, idest primi caeli sive primi orbis, quod semper similiter agit.	2512. Therefore this mover which acts in different ways must be one that “acts in one way of itself,” i.e., by its own power, inasmuch as it causes the diversity found in generation and destruction. And it must act “in another way in virtue of something else,” i.e., by the power of some other agent, inasmuch as it causes eternal generation and destruction. Hence this second agent must act either “in virtue of some third agent,” i.e., by the power of some other agent, “or of the first,” i.e., by the power of the first agent, which always acts in the same way. And since it is not possible to assign some other agent by whose power this first agent brings about the eternal motion of things, it is therefore necessary according to this “that it act in the same way”; that is, that by its power it causes the eternal generation and destruction of things. For it—the first agent—which always acts in the same way, is the cause of that which acts in different ways. For that which acts in different ways acts eternally, and that which acts in the same way is the cause of the eternality of any motion. Hence it is the cause of the eternality of that which acts in different ways inasmuch as the latter acts eternally in this way; and it is also the cause of that which is produced by it, namely, eternal generation and destruction. From this it is also evident that the second agent, which acts in different ways, acts by the power “of the first agent,” i.e., the first heaven or first orb, which always acts in the same way.
lib. 12 l. 6 n. 14 Sic ergo patet, quod primum agens, quod semper similiter agit, est potius et dignius, quia ipsum est causa eius quod est semper esse similiter, idest perpetuitatis. Sed eius, quod est esse aliter et aliter, causa est alterum agens, quod aliter et aliter agit. Eius vero, quod est aliter et aliter se habere, quod est generationem et corruptionem esse perpetuam: manifestum est, quod sunt causa ambo coniunctim, scilicet et primum quod semper similiter agit, et secundum quod aliter et aliter agit.	2513. Hence it is clear that the first agent, which always acts in the same way, is more powerful and nobler, because it is the cause of that “whose being is always to be the same,” i.e., of eternality. But the cause of that whose being is to be different is another agent, which acts in different ways. And it is evident that both of these combined, i.e., both the first agent, which always acts in the same way, and the second agent, which acts in different ways, are the cause of that which both always is and is in different states, namely, the fact that generation and destruction are eternal.
lib. 12 l. 6 n. 15 Ex hoc autem concludit quod si sic se habent motus caeli, quod ex eis potest causari perpetuitas generationis et corruptionis in istis inferioribus, non oportet quaerere aliqua alia principia, scilicet ideas, sicut Platonici posuerunt, vel amicitiam et litem, sicut posuit Empedocles: quia per hunc modum convenit assignare causam perpetuitatis generationis et corruptionis.	2514. Again, he concludes from this that, if the motions of the heavens are such that eternal generation and destruction in the realm of lower bodies can be caused by them, it is not necessary to look for any other principles (such as the Ideas, which the Platonists posited, or love and hate, which Empedocles posited), because it is possible to account for the eternal generation and destruction of things in the above way.
lib. 12 l. 6 n. 16 Et si iste modus non ponatur, sequentur inconvenientia, ad quae deducti sunt primi philosophantes, scilicet quod omnia fiant ex nocte, idest ex simplici privatione, aut quod omnia simul fuerint, vel quod aliquid fiat ex non ente.	2515. And if this way is not accepted, the untenable conclusions to which the first philosophers were led will follow namely, that all things “will come from Night,” i.e., from a simple privation, or “all things were together,” or something comes from non-being.
lib. 12 l. 6 n. 17 Manifestum est ergo, quod praedicta positione servata, scilicet quod sit perpetua generatio et corruptio causata a motu caeli perpetuo, solventur praedicta inconvenientia; et sequetur, quod aliquid semper moveatur motu qui non cessat, qui est motus circularis. Et hoc non solum apparet ratione, sed ex ipso effectu et per sensum: unde necesse est, quod primum caelum, eo quod semper hoc motu movet, sit sempiternum.	2516. Therefore it is evident that, if the above-mentioned position is accepted, i.e., that eternal generation and destruction are caused by the eternal motion of the heavens, the foregoing untenable conclusions are eliminated. And it will follow that something is always being moved in an unceasing motion, which is circular motion. This becomes apparent not only by reasoning but from the effect itself and by perception. Hence, since the first heaven always causes motion by means of this motion, it must be eternal.
lib. 12 l. 6 n. 18 Deinde cum dicit est igitur concludit ex praedictis perpetuitatem motoris immobilis. Cum enim omne quod movetur, ab alio moveatur, ut in physicis probatum est; si caelum est perpetuum, et motus est perpetuus, necesse est aliquod esse movens perpetuum. Sed quia in ordine mobilium et moventium inveniuntur tria, quorum ultimum est quod movetur tantum, supremum autem est movens quod non movetur, medium autem est quod movetur et movet; necesse est, quod ponatur aliquod sempiternum movens quod non movetur. Probatum est enim in octavo physicorum, quod cum non sit abire in infinitum in moventibus et motis, oportet devenire in aliquod primum movens immobile: quia et si deveniatur in aliquod movens seipsum, iterum ex hoc oportet devenire in aliquid movens immobile, ut ibi probatum est.	2517. Therefore, there is (1066). From what has been said above he next infers that there is an eternal unmoved mover. For since everything which is being moved is being moved by something else, as has been proved in the Physics, if both the heavens and their motion are eternal, there must be an eternal mover. But since three classes are found among movers and things moved: the lowest of which is something that is merely moved, the highest something that moves but is unmoved, and the intermediate something that both moves and is moved, we must assume that there is an eternal mover which is unmoved. For it has been proved in Book VIII of the Physics that, since there cannot be an infinite number of movers and things moved, we must come to some first unmoved mover. For even if one might come to something that moves itself, it would again be necessary for the above reason to come to some unmoved mover, as has been proved in that work.
lib. 12 l. 6 n. 19 Si autem primum movens est sempiternum et non motum, oportet quod non sit ens in potentia; quia quod est ens in potentia natum est moveri;- sed quod sit substantia per se existens, et quod eius substantia sit actus. Et hoc est quod supra concluserat. Sed necesse fuit movere dubitationem quae erat apud antiquos, ut ea soluta ostenderetur expressius, quo ordine necesse est pervenire ad primum ens, cuius substantia est actus.	2518. Again, if the first mover is eternal and unmoved, it must not be a potential being (because any potential being is naturally fitted to be moved) but an independent substance whose essence is actuality.—This is the conclusion which he drew above (1058:C 2499). But it was necessary to raise this question, which was discussed among the ancients, in order that when it has been solved the course to be followed in reaching a first being whose substance is actuality will be made more evident.