This is a lot of words, but they aren’t difficult; it reads quickly. I have cut out extra proofs, which can be had at the links. There’s also not much to say about this chapter, except at the end, mostly because I don’t think it will be controversial.
 AGAIN. From what has been said it may be shown that God in the creation of things did not work of necessity, as though He brought things into being as a debt of justice.
 For justice, according to the Philosopher (5 Ethic.), is towards another person to whom it renders his due. But nothing, to which anything may be due, is presupposed to the universal production of things. Therefore the universal production of things could not result from a debt of justice.
 Again. Since the act of justice is to render to each one that which is his own, the act by which a thing becomes one’s own precedes the act of justice, as appears in human affairs: for a man by working has a right to call his own that which, as an act of justice, is rendered to him by the person who pays him. Therefore the act whereby a person first acquires something of his own cannot be an act of justice. Now a created thing begins to have something of its own by creation. Therefore creation does not proceed from a debt of justice.
 Further. No one owes something to another except from the fact that in some way he depends on him or receives something either from him or from a third, on whose account he owes something to the other: for thus a son is a debtor to his father, because he receives being from him; a master to his servant, because he receives from him the service he requires; and every man is a debtor to his neighbour for God’s sake, from Whom we have received all good things. But God is dependent on no one, nor needs He to receive anything from another, as is manifestly clear from what has been said. Therefore it was not on account of a debt of justice that God brought things into being.
Notes Hence, at the very least, Honor your father and mother, love God, and love your neighbor.
 Moreover. In every genus that which is on account of itself precedes that which is on account of another. Consequently that which is simply first of all causes, is a cause on its own account only: whereas that which acts by reason of a debt of justice does not act on its own account only, for it acts on account of the thing to which the debt is due. Therefore God, since He is the first cause and the first agent, did not bring things into being from a debt of justice…
 Hereby is refuted the error of some who strive to prove that God cannot do save what He does, because He cannot do except what He ought to do. For He does not produce things from a debt of justice, as we have proved.
 Nevertheless, although nothing to which anything can be due precedes the universal creation of things, something uncreated precedes it, and this is the principle of creation. This may be considered in two ways. For the divine goodness precedes as the end and first motive of creation, according to Augustine, who says: Because God is good we exist. Also His knowledge and will precede, as by them things are brought into being.
 Accordingly if we consider the divine goodness absolutely, we find nothing due in the creation of things. For in one way a thing is said to be due to someone on account of another person being referred to him, in that it is his duty to refer to himself that which he has received from that person: thus it is due to a benefactor that he be thanked for his kindness, inasmuch as he who has received the kindness owes this to him. But this kind of due has no place in the creation of things: since there is nothing pre-existent to which it can be competent to owe anything to God, nor does any favour of His pre-exist. In another way something is said to be due to a thing in itself: since that which is required for a thing’s perfection is necessarily due to it: thus it is due to a man to have hands or strength, since without these he cannot be perfect. Now God’s goodness needs nothing outside Him for its perfection. Therefore the production of creatures is not due to Him by way of necessity…
 Moreover. It has been proved that God brings things into being neither by necessity of His nature, nor by necessity of His knowledge, nor by necessity of His will, nor by necessity of His justice. Therefore by no manner of necessity is it due to the divine goodness that things be brought into being…
 If, however, we consider the divine ordinance whereby God decided by His intellect and will to bring things into being, then the production of things proceeds from the necessity of the divine ordinance: for it is impossible that God should decide to do a certain thing which afterwards He did not, otherwise His decision would be either changeable or weak. It is therefore necessarily due to His ordinance that it be fulfilled. And yet this due is not enough for the notion of justice properly so called in the creation of things, wherein we can consider nothing but the action of God in creating: and there is no justice properly speaking between one same person and himself, as the Philosopher says (5 Ethic.). Therefore it cannot be said properly that God brought things into being from a debt of justice, for the reason that He ordained by His knowledge and will to produce them.
 If, however, we consider the production of a particular creature, it will be possible to find therein a debt of justice by comparing a subsequent creature to a preceding one. And I say preceding, not only in time but also in nature.
 Accordingly in those divine effects which were to be produced first, we find no due: but in the subsequent production we find a due, yet in a different order. For if those things that are first naturally, are also first in being, those which follow become due on account of those which precede: for given the causes, it is due that they should have actions whereby to produce their effects. On the other hand if those which are first naturally are subsequent in being, then those which are first become due on account of those which come afterwards; thus it is due that medicine precede in order that health may follow. And in either case there is this in common,–that what is due or necessary is claimed by that which is naturally first from that which is naturally subsequent.
 Now the necessity that arises from that which is subsequent in being, and yet is first by nature, is not absolute but conditional necessity: namely, if this must be done, then that must precede. Accordingly with regard to this necessity, a due is found in the production of creatures in three ways.
First, so that the conditional due is on the part of the whole universe of things in relation to each part thereof that is necessary for the perfection of the universe. For if God willed such a universe to be made, it was due that He should make the sun and moon, and suchlike things without which the universe cannot be.
(Notes Don’t get stuck on “sun and moon”. Thomas means the physical things that are without which no universe can be. This is a sort of anthropic argument.)
Secondly, so that the conditional due be in one creature in relation to another: for instance, if God willed the existence of plants and animals, it was due that He should make the heavenly bodies, whereby those things are preserved; and if He willed the existence of man, it behoved Him to make plants and animals and the like, which man needs for perfect existence: although God made both these and other things of His mere will.
Thirdly, so that the conditional due be in each creature in relation to its parts, properties, and accidents, on which the creature depends either for its being, or for some one of its perfections: thus, given that God willed to make man, it was due, on this supposition, that He should unite in him soul and body, and furnish him with senses and other like aids, both within and without. In all of which, if we consider the matter rightly, God is said to be a debtor not to the creature, but to the fulfilment of His purpose. There is also in the universe another kind of necessity whereby a thing is said to be necessary absolutely.
(Notes Analogy: If God wanted to make a triangle, and He first created two sides, He was bound to create the third. As Thomas says next. Remember cause has four components: formal, material, efficient, and final.)
This necessity depends on causes which precede in being, for instance on essential principles, and on efficient or moving causes. But this kind of necessity cannot find place in the first creation of things, as regards efficient causes. For there God alone was the efficient cause, since to create belongs to Him alone, as we have proved above; while in creating, He works not by a necessity of His nature, but by His will, as we have shown above; and those things which are done by the will cannot be necessitated, except only by the supposition of the end, on account of which supposition it is due to the end that those things should be whereby the end is obtained.
On the other hand, with regard to formal and material causes, nothing hinders us from finding absolute necessity even in the first creation of things. For from the very fact that certain bodies were composed of the elements, it was necessary for them to be hot or cold: and from the very fact that a superficies was drawn in the shape of a triangle, it was necessary that it should have three angles equal to two right angles. Now this necessity results from the relation of an effect to its material or formal cause. Wherefore on this account God cannot be said to be a debtor, but rather does the debt of necessity affect the creature.
But in the propagation of things, where the creature is already an efficient cause, an absolute necessity can arise from the created efficient cause: thus the lower bodies are necessarily influenced by the movement of the sun…
Notes Hence science!