Thomas Aquinas

“ Hence we see that in incorruptible things there is only one individual of each species, forasmuch as the species is sufficiently preserved in the one; whereas in things generated and corruptible there are many individuals of one species for the preservation of the species. Whence it appears that formal distinction is of greater consequence than material. Now, formal distinction always requires inequality, because as the Philosopher says (Metaph. viii, 10) , the forms of things are like numbers in which species vary by addition or subtraction of unity. ”

“ For He brought things into being in order that His goodness might be communicated to creatures, and be represented by them; and because His goodness could not be adequately represented by one creature alone, He produced many and diverse creatures, that what was wanting to one in the representation of the divine goodness might be supplied by another. For goodness, which in God is simple and uniform, in creatures is manifold and divided and hence the whole universe together participates the divine goodness more perfectly, and represents it better than any single creature whatever. ”

“ Hence we must reduce whatever distinction comes from matter to a higher cause. Secondly, because matter is for the sake of the form, and not the form for the matter, and the distinction of things comes from their proper forms. Therefore the distinction of things is not on account of the matter; but rather, on the contrary, created matter is formless, in order that it may be accommodated to different forms. ”

“ Further, it is the part of justice to give unequal to unequal things. But God is just in all His works. Since, therefore, no inequality of things is presupposed to the operation whereby He gives being to things, it seems that He has made all things equal. ”

“ On the contrary, It is said (Ecclus. 33:7) : "Why does one day excel another, and one light another, and one year another year, one sun another sun? [Vulg.: 'when all come of the sun'] . By the knowledge of the Lord they were distinguished." ”

“ The multitude or distinction of things.
(2) Their inequality.
(3) The unity of the world.
Art. 1 - Whether the multitude and distinction of things come from God? Objection 1: It would seem that the multitude and distinction of things does not come from God. For one naturally always makes one. ”