Considering the Kalam
A brief presentation and analysis of the Kalam Cosmological Argument
The Kalam Cosmological Argument, according to which the universe is past-finite and so must have been caused to exist, is perhaps the most accessible and familiar of the classical arguments for the existence of God. While its precise origins are obscure, it is generally credited in significant part to medieval Islamic philosophers, most importantly Al-Ghazali and Ibn Rushd. In contemporary philosophy, it’s been defended most famously by the Christian philosopher and apologist William Lane Craig1 — but also by J.P. Moreland,2 Joshua Rasmussen,3 and Robert Koons4 (among others).
Although I think there are a number of strong arguments for the existence of God, I have personally never counted the Kalam among them (though I have slowly warmed to it a bit over time). I have, however, thought about the argument a great deal, and I always enjoy teaching it in Intro courses. In this essay, I will provide a brief gloss on the Kalam, offering my own assessment of it along the way.
1. The Kalam
The Kalam, as I understand it, is a simple syllogism. It’s clearly deductively valid (i.e., its premises, if true, logically entail its conclusion5). So, in analyzing the argument, we need only consider (a) whether its premises are in fact true and (b) whether the argument, if sound, ultimately justifies belief in God (conceived classically as an omniperfect6 mind) — or at least belief in some entity sufficiently God-like as to appreciably increase the probability that God exists.7
The key ideas behind the Kalam are (a) that those things which are non-eternal (i.e., which begin to exist at some finite point in time) don’t simply “pop” into existence ex nihilo and (b) that the universe is non-eternal (i.e., is a member of the set of things which began to exist). If these two claims are true, then it follows that the universe has a cause. We can state the argument in standard form as follows:
1. Whatever begins to exist has a cause.
2. The universe began to exist.
So,
The universe has a cause.
An important point of clarification: Premise 1 does not entail that God would have a cause, given that God is, by conception, an eternal being (and so did not begin to exist).
Ultimately, advocates of the Kalam think that we can, through conceptual analysis, reason our way to the ultimate conclusion that
C. God exists,
or at least that
C*. An immaterial mind that is the cause of the universe exists.8
2. The Causal Principle
Call the claim “whatever begins to exist has a cause” the Causal Principle. Why should we believe this principle?9 There are a few sets of considerations counting in its favor.
An A Priori Argument
First, we might think that it’s simply an a priori truth: That rational intuition itself reveals that something cannot come from nothing. Certainly some principles — for example, fundamental principles of math, logic, and ethics — can just be seen to be true. For example, we can consider the Principle of Non-Contradiction (according to which a proposition cannot be simultaneously true and false) and immediately perceive that it must be true. Perhaps, in the same way, we can just see that something couldn’t come from nothing (and it does seem true that we can’t literally imagine something coming from nothing. Invariably, when we try to do so, we end up imagining something coming from something, given that one cannot picture “nothing” in one’s mind’s eye.
An A Posteriori Argument
Second, we might think that there’s an a posteriori case for the Causal Principle. We do not, in the ordinary course of things, ever see things popping into existence from nothing. So, plausibly, we’re justified in inferring that it’s a law of nature that things which begin to exist have a cause. And contrary to the perception of many, quantum mechanics has not falsified this principle. Strange things happen in the quantum realm, in which there may be some probabilistic causation. But, as far as I can tell, there are no instances of quantum phenomena coming from nothing; a quantum vacuum state, after all, is (like a remarkable number of things) not nothing.10
An Anti-Skeptical Argument
Third, we might think that presupposition of the Causal Principle is necessary for avoiding a form of radical external world skepticism: If we were to suppose that things could begin to exist uncaused, then this would extend to our sensory perceptions themselves, so that we’d be left without reason to think that there are objects out in the world causing our sensory perceptions. So, according to this line of reasoning, given that radical external world skepticism is false (which we might take as a given on Moorean grounds11), the Causal Principle must be true.12
These considerations together, it seems to me, put the Causal Principle on firm ground. The best move for the skeptic with respect to it, I think, is to deny that we have reason to think that it has application to the universe, itself. Perhaps, the skeptic might suggest, it holds only within the universe. Graham Oppy, for example, has offered this as a response.13 But I think it is, in the end, not a satisfactory response because it renders unexplained the fact that the Causal Principle holds within the universe — whereas this fact is explained on the view that Causal Principle holds of metaphysical necessity (the explanation being: It couldn’t have been otherwise).
3. The Universe Began To Exist (?)
By my lights, Premise 2 is the far more contentious of the Kalam’s premises. Both philosophical and scientific support has been offered on its behalf.
3.1 Scientific Evidence
The Big Bang
According to the Big Bang Theory, the entirety of the observable universe’s matter and energy was, in its initial state, an unimaginably dense singularity which, ~13.8 billion years ago, underwent rapid inflation, giving rise to the known universe. On at least one interpretation of the theory, the Big Bang marks the absolute beginning of matter and energy (not just the beginning of the observable universe). If this interpretation is correct, then, given that the evidence for the Big Bang is overwhelming, we in turn have overwhelming scientific evidence that the universe is past-finite.
However, whether this interpretation of the theory is correct is far from clear. Indeed, the most common view in contemporary cosmology, as best I can tell, is that the Big Bang Theory is just a theory of what happened from the moment that the initial singularity began inflating; it is not a theory of the origins of the singularity, itself.
The Second Law of Thermodynamics
Craig also invokes the Second Law of Thermodynamics in support of Premise 2.14 In a closed physical system, energy tends to become evenly dispersed with time (i.e., it tends towards a state of entropy); if the universe is infinitely old, then the Second Law has had infinite time to work its magic — in which case we should not be here (since energy’s being evenly dispersed throughout the universe would be incompatible with the existence of life).
However, the obvious response from the skeptic is to hold that, while matter and energy did not have an absolute beginning in time, this particular system comprising the observable universe is only ~13.8 billion years old, so that there has been a finite amount of time for energy to disperse throughout the system.
In short, the purported scientific evidence for Premise 2 does not move me much at all. It seems to count as evidence only if interpreted in a highly tendentious way. Now, maybe the tendentious reading is correct. However, as a non-expert, I am not in a position to assess that; to do so, I would need a PhD in cosmology, or its equivalent.
3.2 Philosophical Evidence
The philosophical evidence for Premise 2 has to do with various purported impossibilities involving infinites.
Actual Infinites
On one line that Craig has pursued, there can’t be actual infinites, only hypothetical ones (this is the distinction between things that really exist and those which are fictional, or imaginary — mere products of the mind). This works only if one supposes that there are no abstract objects, like numbers (given that, if they exist, there are infinitely many of them). I think there are such objects (Craig, famously, does not15).
Perhaps, though, abstract objects are special (in one sense, they certainly are). Maybe it’s material objects, specifically, of which there can’t be infinitely many, so that there while there could be infinitely many prime numbers, there couldn’t be infinitely many pebbles.
But I struggle to see why that should be so. It’s true that, as Craig would point out, performing operations, like addition and subtraction, on sets of infinitely many items would produce weird results (e.g., subtract one pebble from an infinite collection and the collection still has infinitely many pebbles…weird). But reality is weird. So, that sort of line of argument fails to move me.
Reaching the Present From An Infinite Past
Craig has also argued that that the universe cannot be past-infinite because that would entail the absurdity that infinitely many past moments have already occurred, such that in principle one (and angel, say) could have counted down from infinity past to the present — thereby completing an infinite countdown. But that would impossible: by definition, an infinite countdown can’t be completed!
This line of argument, too, has long left me cold: It seems clear to me that, given an eternalist view of time — which has long struck me as plausible — we can simply hold that moments in time coexist in a tenseless state, where no moment depends upon some previous moment having passed. On this view, there is just a grand eternal present, in which case, given a past-infinite universe, all the moments in time would be members in but one more infinite set. Provided the possibility of actual infinities, there could be an infinite set of moments just as there could be an infinite set of prime numbers or pebbles.
Causal Finitism
More recently, Koons,16 Rasmussen,17 and Alexander Pruss18 have defended the claim that the universe is finite by arguing for Causal Finitism. According Causal Finitism, causal chains — sequences of cause and effect — must have an absolute beginning (an uncaused cause). Beginningless causal chains, causal finitists argue, are metaphysically impossible. They argue for this by attempting to show that infinite causal chains would give rise to various contradictions.
For example, in the Grim Reaper Paradox, a man, Fred, is set to be killed at 12:00 p.m. by an infinite series of grim reapers. Each reaper will kill Fred if the previous reaper has not. But since intervals of time can be infinitely divided, no particular reaper will be such as to not have a reaper ahead of him who will kill Fred. So, no particular reaper kills Fred, and yet Fred must die.19
If causal chains must be finite, then insofar as a past-infinite universe would entail the existence of such chains, the universe must be finite. Although I’ve yet to be persuaded of the causal finitists’ claim (or done the research that would justify me in becoming so persuaded), this seems to me by far the most promising line of argument for Premise 2.
4. Getting To God
The claim that the universe has a cause is not, of course, straightforwardly equivalent to the claim that God is its cause. There is room for the skeptic to question whether the Kalam really amounts to an argument for the existence of God. Whether it does depends upon whether conceptual analysis on the cause of the universe reveals this cause to be sufficiently God-like.
The cause of the universe would, plausibly, have to be non-physical (given that, by stipulation, the universe contains all that is physical) non-spatial (since space is also contained within the universe). Moreover, it would need to have causal powers (given that it would, by definition, be such as to be capable of causing a universe) — and, moreover, causal powers sufficient at least to cause the universe. This rules out as the cause some kind of impersonal principle, or some causally inert abstract object (such as a number, or a moral fact).
It does not, however, rule out more than one mind collaborating to cause the universe. As I may explain in some future essay, I think that other cosmological arguments — the Argument From Motion, the First Cause Argument, and the Contingency Argument — much more straightforwardly establish the existence of a single first being.20 I can see why there could be only one cause of motion, only one uncaused cause, and only one necessary being. But I see no in-principle reason for ruling out the possibility of, say, a committee of divine beings (lower-case “g” gods, as it were) causing the universe together. One might invoke Occam’s Razor to argue that we should not posit multiple beings where one would do. But Occam’s Razor is a heuristic, not an ironclad metaphysical law, and explanatory considerations (e.g., accounting for the various imperfections of the world) might be thought to offset the simplicity of the single creator hypothesis.
Additionally, it’s not entirely clear that the cause of the universe would have to be eternal — that is, something such that it never began to exist. Even if (as I doubt) there could not in principle be an infinite regress of finite minds begetting finite minds, there could be a long finite regress. Again, this is a weakness which I think is absent from other cosmological arguments.
So, how God-like must the cause of the universe, as such, be? I’m afraid not as God-like as defenders of the Kalam generally have wanted to suggest. Nevertheless, if I became convinced of the syllogism’s soundness, that would non-trivially increase my credence in theism, given (a) that physical reality’s having an external cause raises the probability of theism and (b) that I have other, independent reasons for thinking that specifically God (and not, e.g., a committee of gods or the neo-Platonic One) exists.
Conclusion
In one respect, I love the Kalam: It’s accessible and invites investigation into a host of fascinating questions. But given the difficulty, relative to other cosmological arguments, of establishing God as the universe’s cause, I’m inclined to think that the Kalam supplies, at most, weak evidence for theism.
However, at present I’m not sure whether it supplies even that (given that I’m currently unconvinced that it’s sound, due to my lingering doubts about whether natural reason alone can establish the finitude of the totality of physical reality).
If, in the future, I do come to think that the Kalam is sound, it will almost certainly be because I’ve been persuaded of Causal Finitism. And if that happens, I will post about it here!
References:
Craig, W. L.
—-——(1979). The Kalam Cosmological Argument. London: Macmillan.
—-—-(2003). “The Kalam cosmological argument”. In P. Copan & P. K. Moser (Eds.), The Rationality of Theism (pp. 61–76), London: Routledge.
—-—-(2016). God over all: Divine aseity and the challenge of Platonism. Oxford University Press.
Koons, R. C.
—-——(1997). “A New Look at the Cosmological Argument”. American Philosophical Quarterly, 34(2), 193–211.
———(2014). "A New Kalam Argument: Revenge of the Grim Reaper". Noûs, 48(2), 256–267.
Moore, G. E. (1939). “Proof of an External World”. Proceedings of the British Academy, 25, 273–300.
Moreland, J. P. (1987). Scaling the Secular City: A Defense of Christianity. Grand Rapids, MI: Baker Books.
Oppy, Graham. “Uncaused Beginnings.” Faith and Philosophy, vol. 27, no. 1, 2010, pp. 61–71, doi:10.5840/faithphil20102715.
Pruss, A. R.
—-——(2018). Infinity, Causation, and Paradox. Oxford University Press, pp. 25–100.
—-——with Rasmussen, J. (2018). Necessary Existence. Oxford University Press, pp. 45–60.
Rasmussen, J.
—-——(2018). How Reason Can Lead to God: A Philosopher’s Bridge to Faith. InterVarsity Press.
See Craig (1979 and 2003).
See Moreland (1987).
See Rasmussen (2018).
See Koons (1997 and 2014).
It can quite straightforwardly be reconstructed as a simple modus ponens.
That is, all-perfect: God, as classically conceived, instantiates all possible perfections to the maximal degree.
If some argument gives us good reason to believe that a relatively small range of beings including God exists, then it thereby increases the probability that God, specifically, exists. To elaborate further: If an argument establishes the existence of an extremely powerful, knowledgeable, and good mind, that increases the probability of God’s existence, even if the argument does not decisively rule out the possibility that the mind in question is not perfect in power, knowledge, and goodness.
As Craig is wont to say, it would be a strange form of atheism which affirmed the existence of such a being!
Note that the Causal Principle is narrower than the Principle of Sufficient Reason (PSR), with which it is too often conflated. The PSR, of which there are in fact many specific versions, holds — in its broadest form — that everything has an explanation.
For further discussion, see Koons (2014 and Craig (2003).
The great British philosopher G.E. Moore famously held that any argument for a radically skeptical thesis will inevitably contain some premise whose truth is less believable than its negation. See Moore (1939).
This last point is one which I gleaned from Koons, specifically, during a seminar at UT Austin in Fall 2019.
See Oppy (2010).
See Craig (2003).
See Craig (2016).
See Koons (2014).
See Rasmussen (2018).
See Pruss (2018).
For further discussion, see Koons (2014).
It perhaps bears mentioning at this point that perhaps the greatest defender of the non-Kalam cosmological arguments, St. Thomas Aquinas, was himself famously skeptical of the Kalam.