Respondeo dicendum quod Deum esse quinque viis probari potest. I answer that, The existence of God can be proved in five ways. Prima autem et manifestior via est, quae sumitur ex parte motus. Certum est enim, et sensu constat, aliqua moveri in hoc mundo. Omne autem quod movetur, ab alio movetur. Nihil enim movetur, nisi secundum quod est in potentia ad illud ad quod movetur, movet autem aliquid secundum quod est actu. Movere enim nihil aliud est quam educere aliquid de potentia in actum, de potentia autem non potest aliquid reduci in actum, nisi per aliquod ens in actu, sicut calidum in actu, ut ignis, facit lignum, quod est calidum in potentia, esse actu calidum, et per hoc movet et alterat ipsum. Non autem est possibile ut idem sit simul in actu et potentia secundum idem, sed solum secundum diversa, quod enim est calidum in actu, non potest simul esse calidum in potentia, sed est simul frigidum in potentia. Impossibile est ergo quod, secundum idem et eodem modo, aliquid sit movens et motum, vel quod moveat seipsum. Omne ergo quod movetur, oportet ab alio moveri. The first and more manifest way is the argument from motion. It is certain, and evident to our senses, that in the world some things are in motion. Now whatever is in motion is put in motion by another, for nothing can be in motion except as it is in potentiality to that towards which it is in motion; whereas a thing moves inasmuch as it is in act. For motion is nothing else than the reduction of something from potentiality to actuality. But nothing can be reduced from potentiality to actuality, except by something in a state of actuality. Thus that which is actually hot, as fire, makes wood, which is potentially hot, to be actually hot, and thereby moves and changes it. Now it is not possible that the same thing should be at once in actuality and potentiality in the same respect, but only in different respects. For what is actually hot cannot simultaneously be potentially hot; but it is simultaneously potentially cold. It is therefore impossible that in the same respect and in the same way a thing should be both mover and moved, i.e., that it should move itself. Therefore, whatever is in motion must be put in motion by another. Si ergo id a quo movetur, moveatur, oportet et ipsum ab alio moveri et illud ab alio. Hic autem non est procedere in infinitum, quia sic non esset aliquod primum movens, et per consequens nec aliquod aliud movens, quia moventia secunda non movent nisi per hoc quod sunt mota a primo movente, sicut baculus non movet nisi per hoc quod est motus a manu. If that by which it is put in motion be itself put in motion, then this also must needs be put in motion by another, and that by another again. But this cannot go on to infinity, because then there would be no first mover, and, consequently, no other mover; seeing that subsequent movers move only inasmuch as they are put in motion by the first mover; as the staff moves only because it is put in motion by the hand. Ergo necesse est devenire ad aliquod primum movens, quod a nullo movetur, et hoc omnes intelligunt Deum. Therefore it is necessary to arrive at a first mover, put in motion by no other; and this everyone understands to be God. Secunda via est ex ratione causae efficientis. Invenimus enim in istis sensibilibus esse ordinem causarum efficientium, nec tamen invenitur, nec est possibile, quod aliquid sit causa efficiens sui ipsius; quia sic esset prius seipso, quod est impossibile. The second way is from the nature of the efficient cause. In the world of sense we find there is an order of efficient causes. There is no case known (neither is it, indeed, possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Non autem est possibile quod in causis efficientibus procedatur in infinitum. Quia in omnibus causis efficientibus ordinatis, primum est causa medii, et medium est causa ultimi, sive media sint plura sive unum tantum, remota autem causa, removetur effectus, ergo, si non fuerit primum in causis efficientibus, non erit ultimum nec medium. Sed si procedatur in infinitum in causis efficientibus, non erit prima causa efficiens, et sic non erit nec effectus ultimus, nec causae efficientes mediae, quod patet esse falsum. Now in efficient causes it is not possible to go on to infinity, because 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 cause, whether the intermediate cause be several, or only one. Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Ergo est necesse ponere aliquam causam efficientem primam, quam omnes Deum nominant. Therefore it is necessary to admit a first efficient cause, to which everyone gives the name of God. Tertia via est sumpta ex possibili et necessario, quae talis est. Invenimus enim in rebus quaedam quae sunt possibilia esse et non esse, cum quaedam inveniantur generari et corrumpi, et per consequens possibilia esse et non esse. The third way is taken from possibility and necessity, and runs thus. We find in nature things that are possible to be and not to be, since they are found to be generated, and to corrupt, and consequently, they are possible to be and not to be. Impossibile est autem omnia quae sunt, talia esse, quia quod possibile est non esse, quandoque non est. Si igitur omnia sunt possibilia non esse, aliquando nihil fuit in rebus. Sed si hoc est verum, etiam nunc nihil esset, quia quod non est, non incipit esse nisi per aliquid quod est; si igitur nihil fuit ens, impossibile fuit quod aliquid inciperet esse, et sic modo nihil esset, quod patet esse falsum. Non ergo omnia entia sunt possibilia, sed oportet aliquid esse necessarium in rebus. But it is impossible for these always to exist, for that which is possible not to be at some time is not. Therefore, if everything is possible not to be, then at one time there could have been nothing in existence. Now if this were true, even now there would be nothing in existence, because that which does not exist only begins to exist by something already existing. Therefore, if at one time nothing was in existence, it would have been impossible for anything to have begun to exist; and thus even now nothing would be in existence—which is absurd. Therefore, not all beings are merely possible, but there must exist something the existence of which is necessary. Omne autem necessarium vel habet causam suae necessitatis aliunde, vel non habet. Non est autem possibile quod procedatur in infinitum in necessariis quae habent causam suae necessitatis, sicut nec in causis efficientibus, ut probatum est. But every necessary thing either has its necessity caused by another, or not. Now it is impossible to go on to infinity in necessary things which have their necessity caused by another, as has been already proved in regard to efficient causes. Ergo necesse est ponere aliquid quod sit per se necessarium, non habens causam necessitatis aliunde, sed quod est causa necessitatis aliis, quod omnes dicunt Deum. Therefore we cannot but postulate the existence of some being having of itself its own necessity, and not receiving it from another, but rather causing in others their necessity. This all men speak of as God. Quarta via sumitur ex gradibus qui in rebus inveniuntur. Invenitur enim in rebus aliquid magis et minus bonum, et verum, et nobile, et sic de aliis huiusmodi. Sed magis et minus dicuntur de diversis secundum quod appropinquant diversimode ad aliquid quod maxime est, sicut magis calidum est, quod magis appropinquat maxime calido. Est igitur aliquid quod est verissimum, et optimum, et nobilissimum, et per consequens maxime ens, nam quae sunt maxime vera, sunt maxime entia, ut dicitur II Metaphys. The fourth way is taken from the gradation to be found in things. Among beings there are some more and some less good, true, noble and the like. But more and less are predicated of different things, according as they resemble in their different ways something which is the maximum, as a thing is said to be hotter according as it more nearly resembles that which is hottest; so that there is something which is truest, something best, something noblest and, consequently, something which is uttermost being; for those things that are greatest in truth are greatest in being, as it is written in Metaph. ii. Quod autem dicitur maxime tale in aliquo genere, est causa omnium quae sunt illius generis, sicut ignis, qui est maxime calidus, est causa omnium calidorum, ut in eodem libro dicitur. Now the maximum in any genus is the cause of all in that genus; as fire, which is the maximum heat, is the cause of all hot things. Ergo est aliquid quod omnibus entibus est causa esse, et bonitatis, et cuiuslibet perfectionis, et hoc dicimus Deum. Therefore there must also be something which is to all beings the cause of their being, goodness, and every other perfection; and this we call God. Quinta via sumitur ex gubernatione rerum. Videmus enim quod aliqua quae cognitione carent, scilicet corpora naturalia, operantur propter finem, quod apparet ex hoc quod semper aut frequentius eodem modo operantur, ut consequantur id quod est optimum; unde patet quod non a casu, sed ex intentione perveniunt ad finem. The fifth way is taken from the governance of the world. We see that things which lack intelligence, such as natural bodies, act for an end, and this is evident from their acting always, or nearly always, in the same way, so as to obtain the best result. Hence it is plain that not fortuitously, but designedly, do they achieve their end. Ea autem quae non habent cognitionem, non tendunt in finem nisi directa ab aliquo cognoscente et intelligente, sicut sagitta a sagittante. Now whatever lacks intelligence cannot move towards an end, unless it be directed by some being endowed with knowledge and intelligence; as the arrow is shot to its mark by the archer. Ergo est aliquid intelligens, a quo omnes res naturales ordinantur ad finem, et hoc dicimus Deum. Therefore some intelligent being exists by whom all natural things are directed to their end; and this being we call God. Ad primum ergo dicendum quod, sicut dicit Augustinus in Enchiridio, Deus, cum sit summe bonus, nullo modo sineret aliquid mali esse in operibus suis, nisi esset adeo omnipotens et bonus, ut bene faceret etiam de malo. Hoc ergo ad infinitam Dei bonitatem pertinet, ut esse permittat mala, et ex eis eliciat bona. Reply Obj. 1: As Augustine says (Enchiridion xi): Since God is the highest good, He would not allow any evil to exist in His works, unless His omnipotence and goodness were such as to bring good even out of evil. This is part of the infinite goodness of God, that He should allow evil to exist, and out of it produce good. Ad secundum dicendum quod, cum natura propter determinatum finem operetur ex directione alicuius superioris agentis, necesse est ea quae a natura fiunt, etiam in Deum reducere, sicut in primam causam. Similiter etiam quae ex proposito fiunt, oportet reducere in aliquam altiorem causam, quae non sit ratio et voluntas humana, quia haec mutabilia sunt et defectibilia; oportet autem omnia mobilia et deficere possibilia reduci in aliquod primum principium immobile et per se necessarium, sicut ostensum est. Reply Obj. 2: Since nature works for a determinate end under the direction of a higher agent, whatever is done by nature must needs be traced back to God, as to its first cause. So also whatever is done voluntarily must also be traced back to some higher cause other than human reason or will, since these can change or fail; for all things that are changeable and capable of defect must be traced back to an immovable and self-necessary first principle, as was shown in the body of the Article. Quaestio 3 Question 3 De Dei simplicitate The Simplicity of God Cognito de aliquo an sit, inquirendum restat quomodo sit, ut sciatur de eo quid sit. Sed quia de Deo scire non possumus quid sit, sed quid non sit, non possumus considerare de Deo quomodo sit, sed potius quomodo non sit. Primo ergo considerandum est quomodo non sit; secundo, quomodo a nobis cognoscatur; tertio, quomodo nominetur. When the existence of a thing has been ascertained there remains the further question of the manner of its existence, in order that we may know its essence. Now, because we cannot know what God is, but rather what He is not, we have no means for considering how God is, but rather how He is not. Therefore, we must consider: (1) How He is not; (2) How He is known by us; (3) How He is named. Potest autem ostendi de Deo quomodo non sit, removendo ab eo ea quae ei non conveniunt, utpote compositionem, motum, et alia huiusmodi. Primo ergo inquiratur de simplicitate ipsius, per quam removetur ab eo compositio. Et quia simplicia in rebus corporalibus sunt imperfecta et partes, secundo inquiretur de perfectione ipsius; tertio, de infinitate eius; quarto, de immutabilitate; quinto, de unitate. Now it can be shown how God is not, by denying Him whatever is opposed to the idea of Him, viz. composition, motion, and the like. Therefore (1) we must discuss His simplicity, whereby we deny composition in Him; and because whatever is simple in material things is imperfect and a part of something else, we shall discuss (2) His perfection; (3) His infinity; (4) His immutability; (5) His unity. Circa primum quaeruntur octo. Concerning His simplicity, there are eight points of inquiry: Primo, utrum Deus sit corpus. (1) Whether God is a body? Secundo, utrum sit in eo compositio formae et materiae. (2) Whether He is composed of matter and form? Tertio, utrum sit in eo compositio quidditatis, sive essentiae, vel naturae, et subiecti. (3) Whether in Him there is composition of quiddity, essence or nature, and subject? Quarto, utrum sit in eo compositio quae est ex essentia et esse. (4) Whether He is composed of essence and existence? Quinto, utrum sit in eo compositio generis et differentiae. (5) Whether He is composed of genus and difference? Sexto, utrum sit in eo compositio subiecti et accidentis. (6) Whether He is composed of subject and accident? Septimo, utrum sit quocumque modo compositus, vel totaliter simplex. (7) Whether He is in any way composite, or wholly simple? Octavo, utrum veniat in compositionem cum aliis. (8) Whether He enters into composition with other things?