God’s creation of the world — everything that exists, the universe, all that there is, etc. — is most properly thought of as a gift. The sense in which we use the term ‘gift’ can be helpfully seen by attending to John Barclay’s recent work on the concept of the gift in Paul. The overlap here is not perfect — Barclay is working on New Testament theology while the present essay is concerned with the metaphysics of creation — but it is a useful heuristic nonetheless (and it should, in any event, remain a heuristic). Of the various ways in which Barclay thinks of the gift, two in particular demand careful attention: gift as superabundance — the maximum scale, lavishness, or permanence of the gift given — and gift as singularity — the attitude of the giver as being solely and purely that of benevolence. Both of these notions are employed by Etienne Gilson and Thomas Aquinas, with the ultimate end of expounding on the absolute freedom of God’s creation.
In The Philosophy of St. Thomas Aquinas (pp. 136–137), Gilson offers three arguments for why creation is a free act of God, unconditioned by any natural necessity — this is crucial for any dogma or metaphysic of creation:
1) It should be said that the universe, by virtue of having been created by God, “is ordered in view of a certain end; otherwise everything in the universe would be produced by chance.” In other words, nature exhibits final causality, that is, it tends toward particular ends which cannot be explained away as the ultimate result of non-intention . This tendency toward particular ends is analogous to the way the will tends toward particular ends, with one crucial distinction. Whereas a being endowed with will acts according to its knowledge — that is, “it acts for an end in the sense that it knows it, that it proposes it to itself” — nature tends toward ends, neither knowing nor willing the end for itself. But if nature can neither “propose an end for itself, nor move toward it, nor order and direct its actions in view of this end”, then the fact that nature exhibits final causality of this sort demands an explanation in terms of “a being endowed with intelligence and will, as the arrow moves toward a specific target because of the guiding hand of the archer.” As Aquinas famously argues in the quinque viae, the reality of final causality leads to God as the Supreme Intelligence which orders all things to their ends, by virtue of his unconditioned will.
2) Consider that a thing will always act according to its mode of being — as the scholastic saying goes, operation follows being. Nature, for example, will always “act in the same way as long as it remains itself.” Particles, flowers, and microorganisms will always perform one and the same action according to the kind of being they are. Now God “is not at all limited to a single mode of being”, for if he acted out of natural necessity, he would produce a being like himself, infinite and indeterminate. But “two simultaneous infinite beings are impossible.”  Hence, it is clear that God does not create out of natural necessity, and, consequently, that God creates freely.
3) There is a proportion between effects and their causes, such that whatever is in an effect must first preexist in the cause, and in accordance with the mode of being of this cause. Now creation, so far as it is intelligible being, must ultimately preexist in the divine intelligence, and, in the final analysis, must proceed from his “inclination to accomplish what his intelligence has conceived” (emphasis added) — that is, by his will. Hence, it should be said that it is “the will of God that is the first cause of all things.” .
Gilson takes these arguments to show that God’s creation is unconditioned by any natural necessity. Creation proceeds according to God’s intelligible mode of being by his will and is thus absolutely free. Having answered the question of God’s free creation, Gilson turns to the question of why God created. It is here that we may recall Barclay’s taxonomy, specifically the categories of superabundance and singularity, since creation will be shown to be the most lavish — as well as the most benevolent — gift.
Gilson argues, echoing Aquinas — who in turn echoes the Neoplatonic tradition — that the good naturally tends to diffuse and give beyond itself in a communicative action: bonum est diffusivum sui:
“What is true of every good being in proportion as it is good, is eminently true of the Supreme Good which we call God. The tendency to propagate and communicate itself expresses then nothing but the superabundance of an infinite Being whose perfection overflows and spreads over a hierarchy of participating beings…” (p. 141)
This appears at first glance to smack of necessity, the kind classical theism has always been careful to avoid. However, Gilson is quick to point out that this tendency of the good to communicate itself outwardly falls short of natural necessity on account of God’s will:
“The proper object of the will is the good: consequently, the goodness of God, in so far as it is desired and loved by Him, is the cause of the creature. But it is so only by the intermediate action of the will. Thus, we assume that there is in God an infinitely powerful tendency to diffuse and communicate Himself outside Himself, and at the same time that He diffuses and communicates Himself only, by an act of His will.” (p. 141)
God’s overflow of goodness, which gives being to the creature as its cause, is thus a free, abundant and benevolent giving of Himself beyond Himself. This free, communicative act is thus the most perfectly free gift:
“We must accordingly hold firmly to this conclusion, that God wills Himself and necessarily wills only Himself; and that, if the super-abundance of His being and His love leads Him to will and to love Himself even in the finite participations of His being, we must see therein nothing but a free gift and nothing even remotely resembling a necessity.” (p. 142)
In creation we have the most benevolent, abundant and free gift that could be given: God himself, who freely, out of love, communicates his goodness and being to finite creatures.
 Aristotle discusses the role of chance as the ultimate explanation of order in the universe in Physics II.4–6. Similarly, see Thomas Aquinas, De Sortibus.
 Aquinas, Summa Theologiae. 1.7.2.
 Ibid. 1. 19. 4; De potentia Dei.3. 10.