#945 A New Modal Argument from Contingency
June 22, 2025Hello Dr. Craig! Recently, Alexander Pruss and Joshua Rasmussen have developed a fascinating, cutting-edge argument called the Modal Argument from Beginnings, or MAB. It seeks to reach the same conclusion of the classic argument from contingency you defend using quite modest premises, and it appears robust. Here is the argument:
1. For any positive state of affairs S that can begin to obtain, it is at least possible for there to be something external to S that causes S to obtain.
2. It is at least possible for there to be a beginning of the positive state of affairs that there exist contingent concrete things.
3. If (1) and (2) are true, it is possible that there exists a necessary concrete thing.
4. It’s possible that a necessary concrete thing exists.
5. If it’s possible that a necessary concrete thing exists, then a necessary concrete thing exists (S5 axiom).
6. Therefore, a necessary concrete thing exists.
This argument is fully compatible with uncaused contingent beginnings, brute facts, ungrounded infinite causal regresses, internal contingent explanations, or circular causal chains. From a "necessary concrete being," it seems like a pretty short inference to theistic considerations, since an impersonal necessity simply cannot ground contingency, as you surely know. My question is, do you think this argument is a good one? Is it plausibly sound? Why or why not? If so, do you think it surpasses the traditional argument from contingency in its modesty, or would you advocate for it being part of a rigorous cumulative case? I would be indebted for your feedback!
Thank you,
Sam
United States
Dr. craig’s response
A
Thank you for sharing with me this intriguing, new modal version of the contingency argument from the fertile minds of Pruss and Rasmussen! Since I have not yet seen their defense of this argument, I’ll respond simply to your summary.
In the traditional argument from contingency, one enunciates some sort of Principle of Sufficient Reason which would justify seeking an explanation for the existence of contingent, concrete things. Pruss and Rasmussen will seek to justify seeking such an explanation on the basis of the mere possibility that contingent, concrete things begin to exist. If it’s even possible for them to begin to exist, then it’s possible that there is a causal explanation of their existence. But then such a cause must exist.
By way of explanation, the positive state of affairs S in (1) is envisioned to be the state of there existing contingent concrete things. It is said that this state of affairs can begin to obtain. That is to say, it is not necessary that contingent concrete things have always existed. So according to premiss (1), if the state of affairs of contingent concrete things’ existing possibly begins to obtain, it is possible for there to be something external to that state of affairs that causes it to obtain.
That cause cannot itself be contingent, otherwise the state of affairs of concrete contingent things’ existing already obtains, contrary to the hypothesis. Hence, this external cause must be a necessarily existent being. Since only concrete objects can stand in relations of cause to effect, this being must be a concrete being. So if it is possible that the state of affairs of concrete contingent things’ existing begins to obtain, it is possible that there is a necessarily existing concrete being that is the external cause of that state’s obtaining.
Premiss (3) merits comment. There are, in fact, two possibilities involved here: first, the possibility of S’s beginning to obtain and, second, the possibility of there being an external cause of the obtaining of S. Even in a world in which concrete contingent things never begin to exist but have existed eternally, it is nonetheless possible that concrete contingent things begin to exist. And even if in a world in which concrete contingent things begin to exist there is no external cause of their existing, still it is possible that there be such an external cause. It follows that possibly a concrete necessary being exists.
Therefore, given the modal logic of system S5, according to which something that is possibly necessary is necessary, a concrete necessary being does exist.
Although Pruss and Rasmussen call their argument the Modal Argument from Beginnings, it clearly bears a close resemblance to the ontological argument. Their argument’s appeal to mere possibility is both its strength and its weakness. On the one hand, an appeal to mere possibility rather than to factuality is more modest. On the other hand, the force of the crucial premisses depends upon the relevant possibilities’ being metaphysical and not merely epistemic. If we agree, as seems plausible, that it is metaphysically possible for any positive state of affairs which begins to obtain to have an external cause, and that it is metaphysically possible that the state of concrete contingent things’ existing begins to obtain, then we should agree that a concrete necessary being exists.
- William Lane Craig