Et sic patet probatio utriusque propositionis quae supponebatur in prima demonstrationis via, qua probat Aristoteles esse primum motorem immobilem. We have thus clearly proved both statements which were supposed in the first process of demonstration by which Aristotle proved the existence of a first immovable mover. Secunda via talis est. Si omne movens movetur, aut haec propositio est vera per se, aut per accidens. Si per accidens, ergo non est necessaria: quod enim est per accidens verum, non est necessarium. Contingens est ergo nullum movens moveri. Sed si movens non movetur, non movet: ut adversarius dicit. Ergo contingens est nihil moveri: nam, si nihil movet, nihil movetur. Hoc autem habet Aristoteles pro impossibili, quod scilicet aliquando nullus motus sit. Ergo primum non fuit contingens: quia ex falso contingenti non sequitur falsum impossibile. Et sic haec propositio, omne movens ab alio movetur, non fuit per accidens vera. The second way (8 Physics 5) is as follows. If every mover is moved, this statement is true either in itself or accidentally. If accidentally, it follows that it is not necessary: for that which is accidentally true is not necessary. Therefore, it is a contingent proposition that no mover is moved. But if a mover be not moved, it does not move, as the opponent asserts. Therefore, it is contingent that nothing is moved, since, if nothing moves, nothing is moved. Now Aristotle holds this to be impossible (8 Physics 1), namely, that at any time there be no movement. Therefore, the first proposition was not contingent, because a false impossibility does not follow from a false contingency. And therefore this proposition, ‘every mover is moved by another,’ was not accidentally true. Item, si aliqua duo sunt coniuncta per accidens in aliquo; et unum illorum invenitur sine altero, probabile est quod alterum absque illo inveniri possit: sicut, si album et musicum inveniuntur in Socrate, et in Platone invenitur musicum absque albo, probabile est quod in aliquo alio possit inveniri album absque musico. Si igitur movens et motum coniunguntur in aliquo per accidens, motum autem invenitur in aliquo absque eo quod moveat, probabile est quod movens inveniatur absque eo quod moveatur. Nec contra hoc potest ferri instantia de duobus quorum unum ab altero dependet: quia haec non coniunguntur per se, sed per accidens. Again, if any two things are found accidentally united in a certain subject, and one of them is to be found without the other, it is probable that the latter can be found without the former: thus if ‘white’ and ‘musical’ are found in Socrates, and ‘musical’ without ‘white’ is found in Plato, it is probable that ‘white’ could be found without ‘musical’ in some subject. Accordingly, if mover and moved be united together in some subject accidentally, and it be found that a certain thing is moved without its being a mover, it is probable that a mover is to be found that is not moved. Nor can one urge against this the case of two things, one of which depends on the other; because those in question are united not per se but accidentally. Si autem praedicta propositio est vera per se, similiter sequitur impossibile vel inconveniens. Quia vel oportet quod movens moveatur eadem specie motus qua movet, vel alia. Si eadem, ergo oportebit quod alterans alteretur, et ulterius quod sanans sanetur, et quod docens doceatur, et secundum eandem scientiam. Hoc autem est impossibile: nam docentem necesse est habere scientiam, addiscentem vero necesse est non habere; et sic idem habebitur ab eodem et non habebitur, quod est impossibile. Si autem secundum aliam speciem motus movetur, ita scilicet quod alterans moveatur secundum locum, et movens secundum locum augeatur, et sic de aliis; cum sint finita genera et species motus, sequetur quod non sit abire in infinitum. Et sic erit aliquod primum movens quod non movetur ab alio. Nisi forte aliquis dicat quod fiat reflexio hoc modo quod, completis omnibus generibus et speciebus motus, iterum oporteat redire ad primam: ut, si movens secundum locum alteretur et alterans augeatur, iterum augens moveatur secundum locum. Sed ex hoc sequetur idem quod prius: scilicet quod id quod movet secundum aliquam speciem motus, secundum eandem moveatur, licet non immediate sed mediate. If, however, the aforesaid proposition is true in itself, again there follows something impossible or unfitting. For the mover must be moved either by the same kind of movement or by another kind. If by the same kind, it follows that whatever causes alteration must itself be altered, and furthermore that the healer must be healed, that the teacher must be taught, and in respect of the same science. But this is impossible: for the teacher must have science, while the learner must not have it, and thus one thing will be both possessed and not possessed by the same person, which is impossible. And if it be moved by another kind of movement—namely, so that what causes alteration be moved in respect of place, and that which moves in respect of place be increased, and so on—it will follow that we cannot go on indefinitely, since the genera and species of movement are finite in number. And thus there will be some first mover that is not moved by another. Unless someone happens to say that a recurrence takes place in this way: when all the genera and species of movement have been exhausted, a return must be made to the first. For instance, if that which moves in respect of place be altered, and that which causes alteration be increased, then again that which is increased be moved in respect of place. But the consequence of this will be the same as before, namely, that which moves by one kind of movement is itself moved by the same kind, although mediately and not immediately. Ergo relinquitur quod oportet ponere aliquod primum quod non movetur ab alio exteriori. It remains, therefore, that we must postulate some first mover that is not moved by anything outside itself. Quia vero, hoc habito quod sit primum movens quod non movetur ab alio exteriori, non sequitur quod sit penitus immobile, ideo ulterius procedit Aristoteles, dicendo quod hoc potest esse dupliciter. Uno modo, ita quod illud primum sit penitus immobile. Quo posito, habetur propositum: scilicet, quod sit aliquod primum movens immobile. Alio modo, quod illud primum moveatur a seipso. Et hoc videtur probabile: quia quod est per se, semper est prius eo quod est per aliud; unde et in motis primum motum rationabile est per seipsum moveri, non ab alio. Since, however, it does not follow that a first mover that is not moved by anything outside itself is absolutely immovable, Aristotle proceeds further, saying that this may happen in two ways. First, so that this first mover is absolutely immovable. And if this is granted, our point is established, namely, that there is a first immovable mover. Second, that this first mover is moved by itself. And this seems probable, because what is of itself is always prior to what is of another. Hence it is likewise logical in things moved that what is moved first is moved by itself and not by another. Sed, hoc dato, iterum idem sequitur. Non enim potest dici quod movens seipsum totum moveatur a toto: quia sic sequerentur praedicta inconvenientia, scilicet quod aliquis simul doceret et doceretur, et similiter in aliis motibus; et iterum quod aliquid simul esset in potentia et actu, nam movens, inquantum huiusmodi, est actu, motum vero in potentia. Relinquitur igitur quod una pars eius est movens tantum et altera mota. Et sic habetur idem quod prius: scilicet quod aliquid sit movens immobile. But, if this be granted, the same consequence follows (8 Physics). For it cannot be said that the whole of what moves itself is moved by its whole self, because then the absurd consequences mentioned above would follow, namely, that a person might teach and be taught at the same time, and in like manner as to other kinds of movement. And again, a thing would be at the same time in act and in potency, since a mover, as such, is in act, while that which is moved is in potency. It remains, therefore, that one part thereof is mover only, and the other part moved. And thus we have the same conclusion as before, namely, that there is something that moves and is itself immovable. Non autem potest dici quod utraque pars moveatur, ita quod una ab altera; neque quod una pars moveat seipsam et moveat alteram; neque quod totum moveat partem; neque quod pars moveat totum: quia sequerentur praemissa inconvenientia, scilicet quod aliquid simul moveret et moveretur secundum eandem speciem motus; et quod simul esset in potentia et actu; et ulterius quod totum non esset primo movens se, sed ratione partis. Relinquitur ergo quod moventis seipsum oportet unam partem esse immobilem et moventem aliam partem. And it cannot be said that both parts are moved, so that one is moved by the other; nor that one part moves both itself and the other; nor that the whole moves a part; nor that part moves the whole, since the above absurdities would follow—namely, that something would both move and be moved by the same kind of movement, and that it would be at the same time in potency and in act, and (finally) that the whole would move itself not primarily, but by reason of its part. It remains, therefore, that in whatever moves itself, one part must be immovable, and must move the other part. Sed quia in moventibus se quae sunt apud nos, scilicet in animalibus, pars movens, scilicet anima, etsi sit immobilis per se, movetur tamen per accidens; ulterius ostendit quod primi moventis seipsum pars movens non movetur neque per se neque per accidens. Since, however, in those things among us which move themselves (namely, animals), the part which moves (namely, the soul), though immovable of itself, is nevertheless moved accidentally, he goes on to show that in the first mover, the part which moves is not moved neither of itself nor accidentally (8 Physics 6). Moventia enim se quae sunt apud nos, scilicet animalia, cum sint corruptibilia, pars movens in eis movetur per accidens. Necesse est autem moventia se corruptibilia reduci ad aliquod primum movens se quod sit sempiternum. Ergo necesse est aliquem motorem esse alicuius moventis seipsum qui neque per se neque per accidens moveatur. For in those things which among us move themselves (namely animals), the part which moves is moved accidentally since they are corruptible. Now those corruptible things which move themselves must be reducible to some first self-mover that is everlasting. Therefore, that which moves itself must have a mover, which is moved neither of itself nor accidentally. Quod autem necesse sit, secundum suam positionem, aliquod movens se esse sempiternum, patet. Si enim motus est sempiternus, ut ipse supponit, oportet quod generatio moventium seipsa quae sunt generabilia et corruptibilia, sit perpetua. Sed huius perpetuitatis non potest esse causa aliquod ipsorum moventium se: quia non semper est. Nec simul omnia: tum quia infinita essent; tum quia non simul sunt. Relinquitur igitur quod oportet esse aliquod movens seipsum perpetuum, quod causat perpetuitatem generationis in istis inferioribus moventibus se. Et sic motor eius non movetur neque per se neque per accidens. It is clear that, in accordance with his hypothesis, some self-mover must be everlasting. For if, as he supposes, movement is everlasting, the production of these self-movers that are subject to generation and corruption must be everlasting. But no one of these self-movers, since it does not always exist, can be the cause of this everlastingness. Nor can all of them together, both because they would be infinite and because they do not exist all together. It follows, therefore, that there must be an everlasting self-mover, that causes the everlastingness of generation in these lower self-movers. And thus its mover is not moved, neither of itself nor accidentally. Item, in moventibus se videmus quod aliqua incipiunt de novo moveri propter aliquem motum quo non movetur a seipso animal, sicut cibo digesto aut aere alterato: quo quidem motu ipse motor movens seipsum movetur per accidens. Ex quo potest accipi quod nullum movens seipsum movetur semper cuius motor movetur per se vel per accidens. Sed primum movens seipsum movetur semper: alias non posset motus esse sempiternus, cum omnis alius motus a motu primi moventis seipsum causetur. Relinquitur igitur quod primum movens seipsum movetur a motore qui non movetur neque per se neque per accidens. Again, we observe that in self-movers some begin to be moved anew on account of some movement whereby the animal is not moved by itself, for instance, by the digestion of food or a change in the atmosphere. By this movement, the mover that moves itself is moved accidentally. From this, we may gather that no self-mover whose mover is moved essentially or accidentally is always moved. But the first self-mover is always in motion, else movement could not be everlasting, since every other movement is caused by the movement of the first self-mover. It follows, therefore, that the first self-mover is moved by a mover who is not moved, neither essentially nor accidentally. Nec est contra hanc rationem quod motores inferiorum orbium movent motum sempiternum, et tamen dicuntur moveri per accidens. Quia dicuntur moveri per accidens non ratione sui ipsorum, sed ratione suorum mobilium, quae sequuntur motum superioris orbis. Nor is this argument rebutted by the fact that the movers of the lower spheres cause an everlasting movement, and yet are said to be moved accidentally. For they are said to be moved accidentally not by reason of themselves, but by reason of the things subject to their motion, which follow the motion of the higher sphere. Sed quia Deus non est pars alicuius moventis seipsum, ulterius Aristoteles, in sua metaphysica, investigat ex hoc motore qui est pars moventis seipsum, alium motorem separatum omnino, qui est Deus. Cum enim omne movens seipsum moveatur per appetitum, oportet quod motor qui est pars moventis seipsum, moveat propter appetitum alicuius appetibilis. Quod est eo superius in movendo: nam appetens est quodammodo movens motum; appetibile autem est movens omnino non motum. Oportet igitur esse primum motorem separatum omnino immobilem, qui Deus est. Since, however, God is not part of a self-mover, Aristotle goes on in his Metaphysics 11, 7, to trace from this motor that is part of a self-mover, another mover altogether separate, which is God. For, since every self-mover is moved through its appetite, it follows that the motor which is part of a self-mover moves on account of the appetite for some appetible object. And this object is above the motor in moving, because the one desiring is a moved mover, whereas the appetible is a mover altogether unmoved. Therefore, there must be a first mover separate and altogether immovable, and this is God. Praedictos autem processus duo videntur infirmare. Quorum primum est, quod procedunt ex suppositione aeternitatis motus: quod apud Catholicos supponitur esse falsum. Now two things would seem to weaken the above arguments. The first of these is that they proceed from the supposition of the eternity of movement, and among Catholics this is supposed to be false. Et ad hoc dicendum quod via efficacissima ad probandum Deum esse est ex suppositione aeternitatis mundi, qua posita, minus videtur esse manifestum quod Deus sit. Nam si mundus et motus de novo incoepit, planum est quod oportet poni aliquam causam quae de novo producat mundum et motum: quia omne quod de novo fit, ab aliquo innovatore oportet sumere originem; cum nihil educat se de potentia in actum vel de non esse in esse. To this we reply that the most effective way to prove God’s existence is from the supposition of the eternity of the world: when this is supposed, God’s existence seems less manifest. For if the world and movement had a beginning, it is clear that we must suppose some cause to have produced the world and movement, because whatever becomes anew must take its origin from some cause of its becoming, since nothing evolves itself from potency to act, or from non-being to being. Secundum est, quod supponitur in praedictis demonstrationibus primum motum, scilicet corpus caeleste, esse motum ex se. Ex quo sequitur ipsum esse animatum. Quod a multis non conceditur. The second is that the aforesaid arguments suppose that the first moved thing, namely, the heavenly body, has its motive principle in itself, from which it follows that it is animated. Many do not grant this. Et ad hoc dicendum est quod, si primum movens non ponitur motum ex se, oportet quod moveatur immediate a penitus immobili. Unde etiam Aristoteles sub disiunctione hanc conclusionem inducit: quod scilicet oporteat vel statim devenire ad primum movens immobile separatum, vel ad movens seipsum, ex quo iterum devenitur ad movens primum immobile separatum. To this we reply that if the first mover is not supposed to have its motive principle in itself, it follows that it is immediately moved by something altogether immovable. Hence also Aristotle draws this conclusion with an alternative, namely, that either we must come at once to a first mover immovable and separate, or to a self-mover from which again we come to a first mover immovable and separate (8 Physics 5, 12). Procedit autem Philosophus alia via in II Metaphys., ad ostendendum non posse procedi in infinitum in causis efficientibus, sed esse devenire ad unam causam primam: et hanc dicimus Deum. Et haec via talis est. In omnibus causis efficientibus ordinatis primum est causa medii, et medium est causa ultimi: sive sit unum, sive plura media. Remota autem causa, removetur id cuius est causa. Ergo, remoto primo, medium causa esse non poterit. Sed si procedatur in causis efficientibus in infinitum, nulla causarum erit prima. Ergo omnes aliae tollentur, quae sunt mediae. Hoc autem est manifeste falsum. Ergo oportet ponere primam causam efficientem esse. Quae Deus est. The Philosopher proceeds in a different way in 2 Metaphysics to show that it is impossible to proceed to infinity in efficient causes, but that we must come to one first cause: and this we call God. This is how he proceeds. In all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate, whether the intermediate be one or several. Now if the cause be removed, that which it causes is removed. Therefore, if we remove the first, the intermediate cannot be a cause. But if we go on to infinity in efficient causes, no cause will be first. Therefore, all the others which are intermediate will be removed. Now this is clearly false. Therefore, we must suppose the existence of a first efficient cause: and this is God. Potest etiam alia ratio colligi ex verbis Aristotelis. In II enim Metaphys. ostendit quod ea quae sunt maxime vera, sunt et maxime entia. In IV autem Metaphys. ostendit esse aliquid maxime verum, ex hoc quod videmus duorum falsorum unum altero esse magis falsum, unde oportet ut alterum sit etiam altero verius; hoc autem est secundum approximationem ad id quod est simpliciter et maxime verum. Ex quibus concludi potest ulterius esse aliquid quod est maxime ens. Et hoc dicimus Deum. Another reason can be drawn from the words of Aristotle. For in 2 Metaphysics 1, 5, he shows that those things which excel as true excel as beings, and in 4 Metaphysics 3, 4, 27-28, he shows that there is something supremely true because we see that of two false things one is falser than the other, from which it follows that one is also truer than the other. Now this is by its approximation to that which is simply and supremely true. Therefore, we may further conclude that there is something that is supremely being. And this we call God. Ad hoc etiam inducitur a Damasceno alia ratio sumpta ex rerum gubernatione: quam etiam innuit Commentator in II physicorum. Et est talis. Impossibile est aliqua contraria et dissonantia in unum ordinem concordare semper vel pluries nisi alicuius gubernatione, ex qua omnibus et singulis tribuitur ut ad certum finem tendant. Sed in mundo videmus res diversarum naturarum in unum ordinem concordare, non ut raro et a casu, sed ut semper vel in maiori parte. Oportet ergo esse aliquem cuius providentia mundus gubernetur. Et hunc dicimus Deum. Another argument in support of this conclusion is adduced by Damascene (On the Orthodox Faith 1, 3) from the government of things, and the same reasoning is indicated by the Commentator in 2 Physics. It runs as follows. It is impossible for contrary and discordant things to accord in one order always or frequently except by someone’s governance, through which each and all are made to tend to a definite end. Now we see that in the world things of different natures accord in one order, not seldom and fortuitously, but always or for the most part. Therefore, it follows that there is someone by whose providence the world is governed. And this we call God. Caput 14 Chapter 14 Quod ad cognitionem Dei oportet uti via remotionis That to acquire knowledge of God one must use the way of remotion Ostenso igitur quod est aliquod primum ens, quod Deum dicimus, oportet eius conditiones investigare. Accordingly, having proved that there is a first being which we call God, we must inquire into his nature. Est autem via remotionis utendum praecipue in consideratione divinae substantiae. Nam divina substantia omnem formam quam intellectus noster attingit, sua immensitate excedit: et sic ipsam apprehendere non possumus cognoscendo quid est. Sed aliqualem eius habemus notitiam cognoscendo quid non est. Tantoque eius notitiae magis appropinquamus, quanto plura per intellectum nostrum ab eo poterimus removere. Tanto enim unumquodque perfectius cognoscimus, quanto differentias eius ad alia plenius intuemur: habet enim res unaquaeque in seipsa esse proprium ab omnibus aliis rebus distinctum. Unde et in rebus quarum definitiones cognoscimus, primo eas in genere collocamus, per quod scimus in communi quid est; et postmodum differentias addimus, quibus a rebus aliis distinguatur; et sic perficitur substantiae rei completa notitia. Now in treating of the divine essence the principal method to be followed is that of remotion. For the divine essence by its immensity surpasses every form to which our intellect reaches; and thus we cannot apprehend it by knowing what it is. But we have some knowledge of it by knowing what it is not, and we come closer to the knowledge of it insofar as we can remove a greater number of things from it by our intellect. For the more completely we see how a thing differs from others, the more perfectly we know it, since each thing has in itself its own being distinct from all other things. Thus, when we know the definition of a thing, first we place it in a genus, by which we know in general what it is, and afterwards we add differences to mark its distinction from other things, and thus we arrive at the complete knowledge of a thing’s essence. Sed quia in consideratione substantiae divinae non possumus accipere quid, quasi genus; nec distinctionem eius ab aliis rebus per affirmativas differentias accipere possumus, oportet eam accipere per differentias negativas. Sicut autem in affirmativis differentiis una aliam contrahit, et magis ad completam designationem rei appropinquat secundum quod a pluribus differre facit; ita una differentia negativa per aliam contrahitur, quae a pluribus differre facit. Sicut, si dicamus Deum non esse accidens, per hoc ab omnibus accidentibus distinguitur; deinde si addamus ipsum non esse corpus, distinguemus ipsum etiam ab aliquibus substantiis; et sic per ordinem ab omni eo quod est praeter ipsum, per negationes huiusmodi distinguetur; et tunc de substantia eius erit propria consideratio cum cognoscetur ut ab omnibus distinctus. Non tamen erit perfecta: quia non cognoscetur quid in se sit. Since, however, we are unable in treating of the divine essence to take ‘what’ as a genus, nor can we express its distinction from other things by affirmative differences, we must express it by negative differences. Now, just as in affirmative differences one restricts another, and brings us the nearer to a complete description of the thing according as it makes it differ from more things, so one negative difference is restricted by another that marks a distinction from more things. Thus, if we say that God is not an accident, we thereby distinguish him from all accidents; then if we add that he is not a body, we shall distinguish him also from certain substances, and thus in gradation he will be differentiated by suchlike negations from all beside himself. And then, when he is known as distinct from all things, we shall arrive at a proper consideration of him. It will not, however, be perfect, because we shall not know what he is in himself. Ad procedendum igitur circa Dei cognitionem per viam remotionis, accipiamus principium id quod ex superioribus iam manifestum est, scilicet quod Deus sit omnino immobilis. Quod etiam auctoritas sacrae Scripturae confirmat. Dicitur enim Malach. 3:6: ego Deus, et non mutor; Iac. 1:17: apud quem non est transmutatio; et Num. 23:19: non est Deus quasi homo, ut mutetur. Therefore, in order to proceed by the way of remotion about the knowledge of God, let us take as principle that which is already made manifest by what we have said above (ch. 13), namely, that God is altogether unchangeable. This is also confirmed by the authority of Sacred Scripture. For it is said: I am God and I do not change (Mal 3:6); with whom there is no change (Jas 1:17); and: God is not as a man that he should be changed (Num 23:19). Divina natura The divine nature Caput 15 Chapter 15 Quod Deus sit aeternus That God is eternal Ex hoc autem apparet ulterius Deum esse aeternum. From the foregoing it is also clear that God is eternal. Nam omne quod incipit esse vel desinit, per motum vel mutationem hoc patitur. Ostensum autem est Deum esse omnino immutabilem. Est igitur aeternus, carens principio et fine. For whatever begins or ceases to be suffers this through movement or change. Now it has been shown (ch. 13) that God is altogether unchangeable. Therefore, he is eternal, having neither beginning nor end. Item. Illa sola tempore mensurantur quae moventur: eo quod tempus est numerus motus, ut patet in IV physicorum. Deus autem est omnino absque motu, ut iam probatum est. Tempore igitur non mensuratur. Igitur in ipso non est prius et posterius accipere. Non ergo habet esse post non esse, nec non esse post esse potest habere, nec aliqua successio in esse ipsius inveniri potest: quia haec sine tempore intelligi non possunt. Est igitur carens principio et fine, totum esse suum simul habens. In quo ratio aeternitatis consistit. Again. Only things which are moved are measured by time, because time is the measure of movement, as is clear in 4 Physics, 11, 5. Now God is absolutely without movement, as we have already proved (ch. 13). Therefore, we cannot mark before and after in him. Therefore, in him there is not being after non-being, nor can he have non-being after being, nor is it possible to find any succession in his being, because these things cannot be understood apart from time. Therefore, he is without beginning and end, and has all his being simultaneously, and in this consists the notion of eternity. Adhuc. Si aliquando non fuit et postmodum fuit, ab aliquo eductus est de non esse in esse. Non a seipso: quia quod non est non potest aliquid agere. Si autem ab alio, illud est prius eo. Ostensum autem est Deum esse primam causam. Non igitur esse incoepit. Unde nec esse desinet: quia quod semper fuit, habet virtutem semper essendi. Est igitur aeternus. Moreover. If at any time he was not and afterwards was, he was brought by someone out of non-being into being. Not by himself, because what is not cannot do anything. And if by another, this other is prior to him. Now it has been shown (ch. 13) that God is the first cause. Therefore, he did not begin to be. Therefore, neither will he cease to be, because that which always was has the power to always be. Therefore, he is eternal. Amplius. Videmus in mundo quaedam quae sunt possibilia esse et non esse, scilicet generabilia et corruptibilia. Omne autem quod est possibile esse, causam habet: quia, cum de se aequaliter se habeat ad duo, scilicet esse et non esse, oportet, si ei approprietur esse, quod hoc sit ex aliqua causa. Sed in causis non est procedere in infinitum, ut supra probatum est per rationem Aristotelis. Ergo oportet ponere aliquid quod sit necesse esse. Omne autem necessarium vel habet causam suae necessitatis aliunde; vel non, sed est per seipsum necessarium. Non est autem procedere in infinitum in necessariis quae habent causam suae necessitatis aliunde. Ergo oportet ponere aliquod primum necessarium, quod est per seipsum necessarium. Et hoc Deus est: cum sit causa prima, ut ostensum est. Est igitur Deus aeternus: cum omne necessarium per se sit aeternum. Furthermore. We observe that in the world there are certain things which can be and not be, namely, those that are subject to generation and corruption. Now all that can possibly be has a cause: for, since in itself it is equally related to two things (namely, being and not being), it follows that if it acquires being this is the result of some cause. But, as proved above (ch. 13) by Aristotle’s argument, we cannot go on to infinity in causes. Therefore, we must suppose something with necessary existence. Now every necessary thing either has a cause of its necessity from without, or has no such cause, but is necessary of itself. But we cannot go on to infinity in necessary things that have causes of their necessity from without. Therefore, we must suppose some first necessary thing which is necessary of itself: and this is God, since he is the first cause, as proved above (ch. 13). Therefore, God is eternal, since whatever is necessary of itself is eternal. Ostendit etiam Aristoteles ex sempiternitate temporis sempiternitatem motus. Ex quo iterum ostendit sempiternitatem substantiae moventis. Prima autem substantia movens Deus est. Est igitur sempiternus. Negata autem sempiternitate temporis et motus, adhuc manet ratio ad sempiternitatem substantiae. Nam, si motus incoepit, oportet quod ab aliquo movente incoeperit. Qui si incoepit, aliquo agente incoepit. Et sic vel in infinitum ibitur; vel devenietur ad aliquid quod non incoepit. Again. Aristotle proves the everlastingness of movement from the everlastingness of time (8 Physics 1, 10). And from this, he goes on to prove the everlastingness of the substance that is the cause of movement (8 Physics 6, 3). Now the first moving substance is God. Therefore, he is everlasting. And supposing the everlastingness of time and movement to be denied, there still remains the argument in proof of the everlastingness of substance. For if movement had a beginning, it must have had its beginning from some mover. And if this mover had a beginning, it had its beginning from some agent. And thus either we shall go on to infinity, or we shall come to something without a beginning.