The Contingency Argument

A (hopefully) accessible explanation and defense of one of the classical arguments for the existence of God

“The Pillars of Creation”, NASA, ESA/Hubble and the Hubble Heritage Team

The first argument I discussed in my post, “Fifteen Arguments For the Existence of God”, was the Contingency Argument. There was a reason for this: For my money, that argument is the single strongest for God’s existence¹ — and certainly it’s the best argument from classical natural theology. This is, no doubt, why it’s been defended (in various forms) by such philosophical giants as Plato, Aristotle, Plotinus, St. Augustine, John Philoponus, Ibn Sina, Al-Ghazali, St. Bonaventure, St. Thomas Aquinas, John Duns Scotus, René Descartes, Gottfried Wilhelm Leibniz, and Samuel Clarke.

Here, I will give the Contingency Argument a more thorough treatment, explaining why, to my mind, it should, ultimately, lead one to think (i) that there is a necessary foundation of reality and (ii) that the necessary foundation is most likely an unlimited mind. Then, I will raise and respond to some perennial objections to the argument.

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1. The Contingency Argument

In order to understand the Contingency Argument, one must understand (i) the distinction between the properties of contingency and necessity, (ii) the reasons for thinking that the universe is contingent, (iii) the principle of sufficient reason (PSR), and the idea of God as classically conceived. In essence, the argument is that the universe (physical reality) is a contingent thing, thereby crying out for explanation — an explanation which only God (as classically conceived) could supply.

1.1 Contingency and Necessity

If something is contingent, that means that it could have been otherwise. Things that come into existence are contingent by virtue of the fact that they once did not exist. We are contingent beings, and we live in a world of other such beings. The events of history also seem to be contingent given that, commonsensically, history could have unfolded differently. The world wars, for instance, might not have occurred had different decisions been made by the relevant actors.

Contingent things stand in contrast to necessary things. Something is necessary just in case it could not have failed to be. None of the beings of ordinary, natural experience seem necessary, though it is (relatively) uncontroversial that some propositions (e.g., those which comprise mathematics and logic) are necessarily true.

1.2 The PSR

According to the principle of sufficient reason (PSR), everything requires explanation, either in terms of its own nature, or in terms of some reason outside of itself. Contingencies can only be ultimately accounted for, it seems, by reference to some necessity. When some contingent thing, x, is explained in terms of some further contingent thing, y, we then have to explain y.

Many take the PSR to be a basic principle of rationality. It captures the thought that it is never intellectually acceptable to insist that something just is – that it has no explanation whatsoever (including in terms of itself).

1.3 The universe’s contingency

There are at least two senses in which the universe appears to be contingent.

First, it seems that it could have failed to exist (indeed, on one way of construing the big bang theory, it did fail to exist until 13.8 billion years ago). That is, it seems conceivable that there could have been nothing, rather than something. So, by the PSR, we need an explanation of why the universe exists at all.

Second, the universe seems to be contingent in the sense that it could have existed very differently than it does: it could, for example, have had a very different causal history, and even different laws of nature (one can imagine, without contradiction, the strong nuclear force, or the force of gravity, being slightly weaker).

1.4 God is the best candidate

Given all the universes which might have existed, why does this one exist? Given all the universes which might have existed, why does this one exist? Proponents of the Contingency Argument say that this question is answerable only by reference to some necessary being (i.e., to some being which could not have failed to be).

Arguably, conceptual analysis reveals God as the best candidate for a necessary being. How so? If you think about the concept of a being that couldn’t be otherwise, you’ll quickly see that there’s strong reason to suppose that it’s the concept of an immaterial being, given that material beings (in all of our experience) are subject to change, destruction, and division. Because the necessary being would have to be beyond the universe (i.e., not itself a member of the set of all contingent things), it would of course have to be beyond the limits of space and time. And since arguably any kind of arbitrary limit on the being’s power would be incompatible with its necessity (since arbitrary limits are, by their nature, limits which could have been otherwise), there’s good reason to suppose that the being would have to be maximally perfect — and a maximally perfect, necessarily existent immaterial being just is what we mean by “God”.

1.5 The Contingency Argument in Standard Form

We can formulate a fairly straightforward statement of the Contingency Argument as follows:

1. The totality of physical reality is at least part of the set of all contingent things (maybe there are contingent non-physical things, such as finite immaterial minds).

2. The set of all contingent things is itself contingent.

3. What’s contingent requires explanation in terms of something beyond itself.

4. So, the set of all contingent things requires explanation in terms of something necessary (given that everything contingent is included in the set of all contingent things).

5. The best candidate for a necessary item which explains all of contingent reality is a maximally perfect mind.

6. So, probably, there exists a maximally perfect mind (i.e., God).

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2. Objections

There are a number of stock objections to the Contingency Argument, but to my mind none are all that compelling on reflection.

2.1 Objection 1: The totality of physical reality is not contingent, but necessary.

There are a few things to say here.

First, the items within the totality of physical reality certainly seem contingent — and if we can imagine each of those items being otherwise, this means that the totality could have been otherwise. A bunch of contingent things don’t add up to something necessary, given that the composite which they create would inherit contingency by way of each of its parts (change a part, and you change the composite as well). To suppose that we’re mistaken about the contingency of the items within physical reality is to cast our modal intuitions (i.e., our intuitions about possibility and necessity) into such doubt as to render them useless.

Second, insofar as theoretical physicists model different ways the universe could have been, we have more than mere metaphysical intuition to guide us; if physical reality is necessary, then its necessity is so well-hidden that we can model different ways that it could have been.

Third, if physical reality is necessary, then it is so in a manner that cries out for explanation; its necessity is surely not brute, but instead grounded in some deeper necessity. To accept the universe as a brute necessity would undermine the very epistemic principles which drive scientific and philosophical inquiry.

2.2 Objection 2: The set of all contingent things is explained by its contingent things explaining one another.

The idea here is that insofar as the contingent features of physical reality are explicable in terms of one another, the whole physical reality is explicable — that is, there’s no explanatory work left to be done after each contingent thing is explained by reference to some other contingent thing.

But that is just manifestly not true. We can wonder, “Why this set of contingent things, rather than some other?”. This is a perfectly good question, and there’s no way to answer it without reference to something outside the set of contingent things.

2.3 Objection 3: The PSR is false.

Since many different iterations of the PSR have been offered, the more precise version of this objection is that “no version of the PSR which entails that the universe — physical reality — needs explaining is true”. That hints at one worry: To get the result that the universe is exempt from the PSR, the principle has to be stated in a contrived and ad hoc way, specifically to avoid an undesired conclusion.

The deeper worry is that rejection of the PSR leads to radical solipsistic skepticism. If we endorse the view that things don’t require explanation, then this will apply to our sensory and cognitive perceptions, such that we’ll lack reason to think that they must be explicable in terms of some external reality.

2.4. Objection 4: There is a necessary being, but it’s not God.

I think this is the best line of objection for the skeptic to pursue.

The skeptic might argue that, for example, the Universal Wave Function, or some other fundamental physical item, is the necessary being. Alternatively, the skeptic might posit some supernatural being other than God as the necessary being — a limited god, rather than God.

Both options are bad, by my lights. Physical things have the markers of contingency: They’re subject to change, limited by space and time, and can be broken down into smaller parts. Likewise, limited supernatural beings: Insofar as such beings are limited in terms of power and other properties, we can wonder why those particular limits obtain — and if such a being is posited as the fundamental item of reality, we can wonder why that item is the fundamental one, rather than some other.

2.5 Objection 5: God is not exempt from the PSR!

Indeed, God isn’t! But the thought is that, insofar as necessity is one of God’s essential properties, God — unlike other entities — is self-explaining. Once one understands (roughly) the nature of God, then one should no longer wonder why God in fact exists.²

2.6 Objection 6: If God is the explanation of all else, then everything is necessary!

This is the modal collapse objection. The idea is that if all apparently contingent things are explained in terms of a necessary being, they inherit the necessary being’s necessity — thereby turning out not to be contingent after all!

The response is simple enough: The necessary being — the unlimited ground of all that exists — must have the power to create contingent things. These contingent things will then be explicable in terms of the necessary being, just not by way of a necessitating relation.

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Conclusion

Although the Contingency Argument is technical, involves some complex notions, and takes real effort to understand, my own sense is that it’s really just a philosophically rigorous articulation of the very common thought that God is needed to explain things — to explain the world. And, for reasons I hope to have made clear in this essay, that thought is (at the very least) well-supported.

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Some recommendations for further reading:

Rasmussen, J. 2021. “Does atheism entail a contradiction?” Manuscrito, 44(4), 31-48.

Koons, R. C., & Pruss, A. R. 2021. “Skepticism and the principle of sufficient reason”. Philosophical Studies, 178(4), 1079-1099.

Pruss, A. R. 2009. “The Leibnizian cosmological argument”. In W. L. Craig & J. P. Moreland (Eds.), The Blackwell companion to natural theology (pp. 24-100). Wiley-Blackwell.

Fuqua, J., & Koons, R. C. (Eds.). 2023. Classical theism: New essays on the metaphysics of God. Routledge.

Ocampo, S. T. 2024. “Strategies for stage II of cosmological arguments”. International Journal for Philosophy of Religion, 96(1), 97-114.

1. This is not to say that it’s the most accessible, or the one most likely to persuade the ordinary person.

2. This is why I think the Ontological Argument succeeds: Conceptual analysis of God reveals God’s existence. Moreover, the Contingency Argument lends credence to the Ontological Argument insofar as it offers independent reason to think that there must be some necessary being.