The cosmological argument for the existence of God is one of the most venerable arguments of classical apologetics. It seeks to infer the existence of God from the existence of the cosmos or of objects within it.1 It comes in two main forms which I will attempt to treat concurrently: the temporal form, which is based on the existence of a cause or explanation for the beginning of the universe, and the nontemporal form (or argument from contingency), which seeks an explanation for why there is something rather than nothing.
The temporal form of the cosmological argument is best known today as the Kalām cosmological argument, which was originally developed by Muslim philosophers but is widely promoted today by Christian apologists like William Lane Craig.2 It has the following structure: 1) Whatever begins to exist has a cause 2) The universe began to exist 3) Therefore, the universe has a cause.3 It is temporal in that is seeks to locate the cause of the beginning of the universe (both temporal and ontological), identifying this "first cause" with God.
The nontemporal form of the cosmological argument, or "argument from contingency" is perhaps stronger since it does not depend on the assumption that the universe began to exist. It is best known as the work of Thomas Aquinas, who assumed (per Aristotle) for the sake of argument that the universe is eternal, since its createdness could only be known by revelation.4 It has the following logical form: 1) If any contingent beings exist, a necessary being exists (as the ultimate cause of their contingent existence) 2) Some contingent beings exist 3) Therefore, a necessary being exists.5 Unlike the temporal form, the nontemporal form does not seek to locate God as the "first cause" of the universe, but rather as the nontemporal reason for its existence when it could just as easily have not existed (this is what it means to be contingent), as the reason why there is something rather than nothing.
Besides their temporal/nontemporal focus, the premises of these arguments correlate fairly closely. The first premises seem evident from everyday experience and common sense: we expect there to be a reason or explanation for everything, even if we don't know it; we never consider that something might "just exist" for literally no reason at all. We implicitly hold to what Gottfried Leibniz called the "principle of sufficient reason", that nothing is true or exists without there being a sufficient reason for its being so and not otherwise,6 for objects in the universe; why should it not also hold for the universe as a whole? This principle is also foundational to the scientific method.
The second premise is supported by philosophy and science, Mathematically, apologists argue, it doesn't make any sense to say that the universe is literally eternal, with no beginning; infinity is just a concept, and it is absurd to propose that (for instance) an actually infinite amount of time has progressed in the universe.7 As well, this objection does not answer the nontemporal form of the argument which assumes a beginningless universe; claiming that the universe (or the existence of matter and energy) is necessary as well as eternal simply makes the cosmos itself into Aquinas' necessary being and is actually closer to pantheism (identifying God with the cosmos) than scientific naturalism. So it is fairly uncontroversial to claim that the universe is contingent, that it could have been (or not been) other than it is. Scientifically, twentieth-century cosmology has strongly supported the Big Bang theory, which postulates a clear beginning to the universe;8 the second law of thermodynamics also indicates that the universe has a finite age.
If these premises are both accepted, some conclusions can be drawn about the first cause/necessary being. (Granting that it is not simply the universe itself) At the very least, it would have to be outside space and time, eternal, and omnipotent in order to be the first/ultimate cause of everything else. To avoid an infinite regress of causes, it must be uncaused, self-existent, or necessary. If we grant that the universe had a beginning, it also seems that this being must be personal, since if the first cause were merely impersonal or mechanical, then the universe would be coeternal with it.9
Unsurprisingly, skeptics have raised a number of objections to the cosmological argument. A common one is to point out that no explanation or cause is given for the first cause/necessary being whose existence is being proven. This is taken to be a form of special pleading, a convenient exemption from the general rule of causality which is argued for everything else; if God does not need a prior cause, why does the universe?10 As well, it is argued that the first cause whose existence the argument seeks to prove is hardly the God of Christianity, since it provides no evidence for, say, his singularity, goodness, immanence, continuing interaction with the universe, or even continuing existence.11 As its employment by Enlightenment philosophers demonstrates, the cosmological argument works just as well for deism (not to mention Islam) as it does for Christianity.
Other objections take issue with the premises of the argument. A variety of scientific theories have offered alternatives to the Big Bang as the beginning of the universe, such as the steady state model, a cyclic universe with an endless series of collapses and "bounces", vacuum fluctuation models, chaotic inflation theory, and the many-worlds hypothesis.12 Another approach is to argue that it because time is a property of the universe, it simply makes no sense to speak of anything "before" the Big Bang, or of its having a "cause", since both of these concepts are dependent on time.13
Other objections question the first premise, that everything has a cause. This is true on an everyday level, but is causality truly universal? In other words, since we know our concept of causality via inductive reasoning, can we use it deductively as a premise of the cosmological argument? Already, quantum physics seems to present a counterexample, making causality less than universal. If we can't assume that the principle of sufficient reason applies in a truly ultimate sense, then it would seem we can't be sure of the soundness of the cosmological argument. Perhaps the question of why we exist is unanswerable, or simply meaningless.14
The objection that no cause is sought for the first cause is a misunderstanding of the argument. The first premise only applies to contingent entities, or objects that begin to exist. Since the first cause is understood by definition as beginningless or necessary, no prior cause or explanation is needed to explain it. "It is not arbitrary to deny that God has a cause, because, if God did have a cause, he would not be God."15 Some forms of this objection are reducible to objections to the second premise; if the universe is caused/had a beginning, then it is reasonable to seek an explanation for it. If what is being objected to is simply the possibility of a necessary/eternal being, that is a whole different, more philosophical argument.
Objections to the second premise are unconvincing. Attempts to get around the Big Bang and show how the universe may have no beginning tend to be highly speculative and nearly as faith-based as theism. Additionally, they apply only to the temporal form of the argument: even if our universe is part of some infinite series or tree of universes, the existence of the whole series is still yet to be explained.16 The question "why is there something rather than nothing?" is unanswered, since it is dependent only on the contingency (not the finitude) of the universe. As previously mentioned, if naturalists argue that besides being eternal, the universe is not contingent (i.e. it is necessary), the resulting worldview would seem to be closer to pantheism (the universe itself is God), which is not a place I think many skeptics would like to go.17
The objection that it makes no sense to speak of anything "before" the Big Bang, or its having a cause, is very interesting, since it actually gets at a central mystery of Christian theology proper, the eternality of God, from a scientific angle. It is true that there is no "before" the Big Bang in the temporal sense. But according to what the vast majority of Christians believe about God, he is able to exist and act outside of space and time in ways we cannot even imagine, which does not make it any less possible. It seems more accurate to say that the kind of causality we are talking about when speaking of a "first cause" is more (onto)logical than temporal.
Objections to the first premise are, in my view, the strongest, or at least the most consistent within a position of philosophical naturalism. The idea of the universe being a quantum fluctuation only pushes the question back, since it assumes the preexistence of the quantum vacuum.18 But objecting to the a priori assumption of universal causality seems at least somewhat promising: perhaps the causality that we consider a universal pattern of reality does not apply on the highest level. Can we be sure? Perhaps the existence of something rather than nothing is absurd, a "brute fact" for which no explanation can be given or should be sought. I know of no refutation of this proposition. But it does seem profoundly at odds with the drive of science to rationally seek explanations for everything. Why give up this quest when it comes to the ultimate reason? At the very least, claiming the universe came from nothing or that its cause is unknowable would seem to be just as much a faith-based claim as claiming that it was created.
Once unacceptable responses have been pared away, debates on the cosmological argument reduce to questions of the principle of sufficient reason: does the existence of the universe have a cause or explanation? This is a question whose answer cannot be "proven" one way or another by logic, science, or anything else. Apologetics can point out this underlying difference between theism and naturalism, but cannot overcome it; this is what is meant when someone points out that "you can't argue someone to Christ." Nonetheless, the cosmological argument is valuable in that it demonstrates the difference between positions and how each is consonant with its respective worldview. It can help to overcome derision and caricatures from each side and promote honest, significant dialogue which has the potential to create real faith.
- C. Stephen Evans and R. Zachary Manis, Philosophy of Religion: Thinking About Faith (Downers Grove, IL: IVP Academic, 2009), 67.
- William Lane Craig, Reasonable Faith: Christian Truth and Apologetics (Wheaton, IL: Crossway, 2008), 96.
- Lee Strobel, The Case for a Creator: A Journalist Investigates Scientific Evidence that Points Toward God (Grand Rapids: Zondervan, 2004), 98.
- Jaroslav Pelikan, The Growth of Medieval Theology (600–1300), vol. 3 of The Christian Tradition: A History of the Development of Doctrine (Chicago: The University of Chicago Press, 1978), 290–291.
- Evans and Manis, Philosophy of Religion, 69–70.
- Craig, Reasonable Faith, 99.
- Strobel, The Case for a Creator, 102–104.
- Strobel, The Case for a Creator, 104–107.
- Strobel, The Case for a Creator, 111.
- Austin Cline, “Cosmological Argument: Does the Universe Require a First Cause?”, About Religion, < http://atheism.about.com/od/argumentsforgod/a/cosmological.htm> (17 February 2015).
- Evans and Manis, Philosophy of Religion, 70.
- Craig, Reasonable Faith, 128–134, 144–150.
- Cline, “The Cosmological Argument.”
- Evans and Manis, Philosophy of Religion, 75.
- Evans and Manis, Philosophy of Religion, 71.
- Evans and Manis, Philosophy of Religion, 74.
- Evans and Manis, Philosophy of Religion, 73; Craig, Reasonable Faith, 109.
- Strobel, The Case for a Creator, 117.