This is the weekly Q & A blog post by our Research Professor in Philosophy, Dr. William Lane Craig.


Dear Dr. Craig:

I am a lay argentine theologian with a PhD from the “Universidad Católica Argentina” (with a thesis on the interaction between scientific cosmology and eschatology), as well as a scientific programmer at the National Atomic Energy Commission. Besides, I have recently created an apology web page “”.

I would like please to pose you the following question:

St. Thomas Aquinas taught that we only know by faith that the universe had a beginning, but it wouldn’t contradict the reason to pose a divine creation of an eternal world (Cf. “On the Eternity of the world”). Perhaps he would have thought differently if he had known the strong arguments about the beginning of space-time arising from the Big Bang or the discovery of the 2nd Law of Thermodynamics.

However, what Aquinas wished to emphasize is that there is no essential correlation between the temporal start of the cosmos and its metaphysical origin, for the latter is the act by which God holds in its being the universe from His Eternity (STh I, q 44, a 1), no matter its beginning or structure. Thus, there is no distinction between the beginning and any of its subsequent moments from the perspective of the creative action itself (cf. STh I, q 104, a 1, ad 4).

My question is: In view of the Kalam cosmological argument, do you think that it exists any correlation between the cosmogonic scientific models of cosmos beginning and its metaphysical origin from divine creation? Or do you rather share St. Thomas’s opinion that it would be possible for God to create a universe without a temporal beginning? (of course, still depending on its existence on God’s creative act).

I pose this question because I consider that a too biased presentation of the Kalam argument (of course, it is not your case) that place exclusively the act of creation in the initial singularity perhaps could fall into concordist interpretations, which would, for example, relate the “Let there be light!” of Genesis 1 with the event of the Big Bang.

Thank you very much. Best regards,



Dr. William Lane Craig’s Response

Thank you for your faithful service to the Lord in Argentina, Claudio! May God greatly use your ministry!

Your letter concerns one of the many issues on which I disagree with Thomas Aquinas. Despite his authoritative status in Catholic thought, I’d encourage you to think independently and not be afraid to challenge him when appropriate.

Aquinas regarded the kalām arguments for the universe’s beginning, which he knew from medieval Islamic theologians, as at best inconclusive. He thought that we should use only strict demonstrations in proving God’s existence to unbelievers, not probability arguments. (Never mind that his own arguments did not approach so high a standard!) Since the kalām arguments did not establish their conclusion with absolute certainty, he did not regard them as successful pieces of natural theology. Hence, even if Aquinas knew of the evidence of contemporary cosmology for the beginning of the universe, he would still have said that it falls short of a strict demonstration and so fails to prove that the universe began to exist. Needless to say, virtually no philosopher today sets the standard for what constitutes a good argument so high. A good argument can establish its conclusion to be more probable than not.

Now Aquinas thought that creation out of nothing was simply God’s bestowal of being, regardless of whether the thing created had a temporal beginning or not. Aquinas was thus unable to distinguish between God’s creating something and God’s conserving something in being. For God’s action in either case is the same.

Intuitively, however, these notions seem distinct. As the medieval theologian John Duns Scotus observed,

Properly speaking . . . it is only true to say that a creature is created at the first moment (of its existence) and only after that moment is it conserved, for only then does its being have this order to itself as something that was, as it were, there before. Because of these different conceptual relationships implied by the words 'create' and 'conserve' it follows that one does not apply to a thing when the other does.[1]

For an analysis of the difference between creation and conservation, I refer you to my article “Creation, Providence, and Miracle,” Let me summarize what I say there about the difference.

Intuitively, creation involves God's bringing something into being that wasn’t there before. We can explicate this notion as follows. For some entity e and some time t,

God creates e at t iff God brings it about that e comes into being at t, where e comes into being at t iff (i) e exists at t, (ii) t is the first time at which e exists, and (iii) e's existing at t is a tensed fact.

By contrast we can explicate divine conservation as follows:

God conserves e iff God acts upon e to bring about e's existing from t until some t*>t through every sub-interval of the interval [t, t* ].

In creation God does not act on a subject, but constitutes the subject by His action; by contrast, in conservation God acts on an existent subject to perpetuate its existence. This is the import of Scotus's remark that only in conservation does a creature "have this order to itself as something that was, as it were, there before." The fundamental difference between creation and conservation, then, lies in the fact that in conservation, as opposed to creation, there is presupposed a subject on which God acts. Moreover, whereas creation can occur at an instant, conservation involves transition and therefore cannot occur at an instant.

Creation and conservation thus cannot be adequately analyzed with respect to the divine act alone, but involve relations to the object of the act. The act itself (the causing of existence) may be the same in both cases, but in one case may be instantaneous and presupposes no prior object, whereas in the other case occurs over an interval and does involve a prior object.

So in answer to your questions, Claudio, no, I do not “share St. Thomas’s opinion that it would be possible for God to create a universe without a temporal beginning.” In fact, I do not think that it would be possible for God to conserve a universe without a temporal beginning, for such a beginningless universe is ruled out by the kalām arguments against the infinitude of the past. Do I think there “exists any correlation between the cosmogonic scientific models of cosmos beginning and its metaphysical origin from divine creation?” Yes, I’m inclined to think that the beginning of cosmic time featured in contemporary cosmogonic models also marks the moment of divine creation. Certainly, it’s possible that prior to the beginning of cosmic time, God was creating angelic realms in a sort of metaphysical time. But we have no reason to posit such a time prior to the beginning of cosmic time, and so it is simpler to suppose that the beginning of cosmic time just is the moment of creation. As you recognize, so saying carries no implication of a concordist hermeneutic, which tries to read contemporary cosmogony into the Bible.


[1] John Duns Scotus, God and Creatures, trans. E. Alluntis and A. Wolter (Princeton: Princeton University Press, 1975), p. 276.

This post and other resources are available on Dr. William Lane Craig's website:

Learn more about Dr. Craig’s book, A Reasonable Response, by clicking here.