1 Objection 1: It would seem that there is not only one world, but many. Because, as Augustine says Questions. 83, qu. 46), it is unfitting to say that God has created things without a reason. But for the same reason He created one, He could create many, since His power is not limited to the creation of one world; but rather it is infinite, as was shown above Question 25, Article 2). Therefore God has produced many worlds.
1 Ad tertium sic proceditur. Videtur quod non sit unus mundus tantum, sed plures. Quia, ut Augustinus dicit, in libro octoginta trium quaest., inconveniens est dicere quod Deus sine ratione res creavit. Sed ea ratione qua creavit unum, potuit creare multos, cum eius potentia non sit limitata ad unius mundi creationem, sed est infinita, ut supra ostensum est. Ergo Deus plures mundos produxit.
2 Objection 2: Further, nature does what is best and much more does God. But it is better for there to be many worlds than one, because many good things are better than a few. Therefore many worlds have been made by God.
2 Praeterea, natura facit quod melius est, et multo magis Deus. Sed melius esset esse plures mundos quam unum, quia plura bona paucioribus meliora sunt. Ergo plures mundi facti sunt a Deo.
3 Objection 3: Further, everything which has a form in matter can be multiplied in number, the species remaining the same, because multiplication in number comes from matter. But the world has a form in matter. Thus as when I say man I mean the form, and when I say this man, I mean the form in matter; so when we say world, the form is signified, and when we say this world, the form in the matter is signified. Therefore there is nothing to prevent the existence of many worlds.
3 Praeterea, omne quod habet formam in materia, potest multiplicari secundum numerum, manente eadem specie, quia multiplicatio secundum numerum est ex materia. Sed mundus habet formam in materia, sicut enim cum dico homo, significo formam, cum autem dico hic homo, significo formam in materia; ita, cum dicitur mundus, significatur forma, cum autem dicitur hic mundus, significatur forma in materia. Ergo nihil prohibet esse plures mundos.
4 On the contrary, It is said Jn. 1, 10): The world was made by Him, where the world is named as one, as if only one existed.
4 Sed contra est quod dicitur Ioan. I, mundus per ipsum factus est; ubi singulariter mundum nominavit, quasi uno solo mundo existente.
5 I answer that, The very order of things created by God shows the unity of the world. For this world is called one by the unity of order, whereby some things are ordered to others. But whatever things come from God, have relation of order to each other, and to God Himself, as shown above Question 11, Article 3; Question 21, Article 1). Hence it must be that all things should belong to one world. Therefore those only can assert that many worlds exist who do not acknowledge any ordaining wisdom, but rather believe in chance, as Democritus, who said that this world, besides an infinite number of other worlds, was made from a casual concourse of atoms.
5 Respondeo dicendum quod ipse ordo in rebus sic a Deo creatis existens, unitatem mundi manifestat. Mundus enim iste unus dicitur unitate ordinis, secundum quod quaedam ad alia ordinantur. Quaecumque autem sunt a Deo, ordinem habent ad invicem et ad ipsum Deum, ut supra ostensum est. Unde necesse est quod omnia ad unum mundum pertineant. Et ideo illi potuerunt ponere plures mundos, qui causam mundi non posuerunt aliquam sapientiam ordinantem, sed casum; ut Democritus, qui dixit ex concursu atomorum factum esse hunc mundum, et alios infinitos.
6 Reply to Objection 1: This reason proves that the world is one because all things must be arranged in one order, and to one end. Therefore from the unity of order in things Aristotle infers Metaph. xii, text 52) the unity of God governing all; and Plato Tim.), from the unity of the exemplar, proves the unity of the world, as the thing designed.
6 Ad primum ergo dicendum quod haec ratio est quare mundus est unus, quia debent omnia esse ordinata uno ordine, et ad unum. Propter quod Aristoteles, in XII Metaphys., ex unitate ordinis in rebus existentis concludit unitatem Dei gubernantis. Et Plato ex unitate exemplaris probat unitatem mundi, quasi exemplati.
7 Reply to Objection 2: No agent intends material plurality as the end forasmuch as material multitude has no certain limit, but of itself tends to infinity, and the infinite is opposed to the notion of end. Now when it is said that many worlds are better than one, this has reference to material order. But the best in this sense is not the intention of the divine agent; forasmuch as for the same reason it might be said that if He had made two worlds, it would be better if He had made three; and so on to infinite.
7 Ad secundum dicendum quod nullum agens intendit pluralitatem materialem ut finem, quia materialis multitudo non habet certum terminum, sed de se tendit in infinitum; infinitum autem repugnat rationi finis. Cum autem dicitur plures mundos esse meliores quam unum, hoc dicitur secundum multitudinem materialem. Tale autem melius non est de intentione Dei agentis, quia eadem ratione dici posset quod, si fecisset duos, melius esset quod essent tres; et sic in infinitum.
8 Reply to Objection 3: The world is composed of the whole of its matter. For it is not possible for there to be another earth than this one, since every earth would naturally be carried to this central one, wherever it was. The same applies to the other bodies which are part of the world.
8 Ad tertium dicendum quod mundus constat ex sua tota materia. Non enim est possibile esse aliam terram quam istam, quia omnis terra ferretur naturaliter ad hoc medium, ubicumque esset. Et eadem ratio est de aliis corporibus quae sunt partes mundi.