Cosmological Arguments for the Existence of God:
An Introduction
Jonathan Webber
`Cosmological' is a name given to a group of arguments for the existence of God, or some
other underlying cause of the universe, which are based on the simple fact that there is a
universe. Such arguments, in various forms, have been advanced by many of the great
figures in the history of thought (such as Plato, Aristotle, Aquinas and Leibniz), and
attacked by many other great figures in the history of thought (such as Hume, Kant, Mill
and Russell). Given this, it is hardly surprising that the debate is complex and, at first,
rather opaque. The aim of this article is to introduce the reader to this debate through a
discussion of some of the key issues surrounding the three most popular forms of the
argument:
[A] The kalam argument.
Everything that has a beginning has a cause. Since the universe had a beginning,
the universe was caused. Since a cause must be distinct from its effect, the universe
must have been caused by a non-physical entity.
[B] The `chain of causes' argument.
Every event is caused by some previous event, which is itself caused.
There is, therefore, a chain of causes. This chain of causes must have its origins
in a First Cause, an efficient cause of the rest of the chain, which is not itself caused.
[C] The argument from contingency.
Events in the universe are contingent (i.e., they need not have occurred).
A contingent event occurs only if it is caused to occur. There is, therefore, a chain
of causes which must have its origins in a necessary being/event (i.e., one that could
not have not existed/occurred). Only God is necessary.
Problems of Causation
All three of the above arguments attempt to show that the universe itself has a cause.
There are three related objections to such a suggestion. David Hume (1711-1776)
claimed that the idea that event-type C causes event-type E arises from human
observation of `constant conjunction' of Cs and Es. That is, if I observe that E follows
immediately from C - every time that C occurs - I come to the conclusion that there is
some `necessary connexion' between the two events, some invisible force due to which
an event of the type E must follow an event of the type C. If Hume is right, it is justifiable
to infer a causal connection between two events only after observing repeated instances
of their conjunction. If this is so, it would be justifiable to infer a cause of the universe
only if other universes had all been observed to follow from some event or agency. Since
this is not possible, there can be no inferences made about a cause of the universe.
A similar objection to the claim that the universe itself may have a cause, or that the
chain of causation may be rooted ultimately outside the universe, is given by Immanuel
Kant in his Critique of Pure Reason (1781). Kant argues that since the concept of
causation arises within the spatio-temporal world of experience, it is confined to the
observable world, so to talk of causation outside of that realm `has no meaning
whatsoever'.
A different experiential objection is raised by John Stuart Mill (1806-1873), in his
article `Theism'. Mill claims that since our experience teaches us that all events are
caused by antecedent events, a cause that was not itself caused cannot be hypothesised;
`Our experience, instead of furnishing an argument for a first cause, is repugnant to it.'
There are, of course, difficulties with the understandings of causation on which the above
objections are based, but it would be a digression to assess this question here. However,
there is a serious conceptual difficulty with rejecting the notion of a cause of the
universe: to do so is implicitly to reject the `principle of sufficient reason'. This is the
principle, proposed by Gottfried Wilhelm Leibniz (1646-1716), that nothing is the way it
is without a sufficient reason for being so. Leibniz's principle is a refinement of the
ancient metaphysical thesis `ex nihilo nihil fit' (of nothing, nothing comes) - or, in the
words of Shakespeare: `Nothing will come of nothing' (King Lear I.i). The whole history
of science has been a gradual realisation that things do not `just happen', but constitute a
subtle and intricate interrelation of events. The history of science, therefore, has
presumed and somewhat vindicated a principle similar to that proposed by Leibniz. To
reject the idea that there is an ultimate cause of the universe is implicitly to reject the
principle of sufficient reason: something will have come from nothing.
It may be argued that the existence of the universe does not necessarily imply a first
cause, since there could be an infinite chain of causes. To argument [C], this is the
objection that every contingent event may simply be due to another contingent event ad
infinitum, so there need be no ultimate cause, no necessary event or being. To arguments
[A] and [B], on the other hand, this is the objection that the causal chains within the
universe may have an infinite history and, as such, the universe itself has no beginning
and, therefore, no ultimate cause.
The Question of Time
The idea that the universe has always existed is philosophically problematic: if history is
infinite in length, not only do we have to claim that infinitude has already occurred, but
also have to agree that as time continues to pass and new events join history, infinity is
being added to. St. Thomas Aquinas (1225-1274) rejected the notion of infinite history
as impossible since, he claimed, if there were no first cause, no subsequent causes would
ever come into being. That is, if the series had no beginning, how does it come about that
the sequence occurs at all?
The currently dominant scientific account of the history of the universe, the `big-bang'
theory, seems to imply that the universe does not have an infinite history. This is the
theory that the universe began as one exceedingly dense, infinitely hot, concentration of
neutrons (the `primeval nucleus'), which exploded. As time went on, the neutrons began
to clump together forming the first `heavy hydrogen' nuclei. This process of expansion
and therefore cooling and structure-formation has resulted in the universe as it is today,
and is continuing. There are three major pieces of evidence in favour of this theory.
Firstly, it was claimed in 1948 that if the big bang theory is correct, there would still be
traces of radiation from the initial explosion at a temperature little above `absolute zero' (273 degrees C). In 1965, this radiation was shown to exist. Secondly, calculations of the
relative amounts of various elements in the universe, based on the big bang theory,
accord well with observations of the universe. Thirdly, there is (at present) no way of
accounting for the inordinate amount of helium in the universe other than the big bang
theory.
However, in his A Brief History of Time (1988), Stephen Hawking offers an alternative
view: the model of space-time curvature. Hawking proposes that the four dimensions of
space and time are considered as together forming a `surface' which is finite in size, but
has no beginning or end - similar to the surface of a sphere. Hawking insists that this `is
just a proposal: it cannot be deduced from some other principle'. In conjunction with
quantum mechanics, this theory can explain all the complex structures in the universe.
The existence of quasars, on the other hand, presents a difficulty for Hawking: quasars
(or `radio-stars') are thought to represent past explosions, and therefore seem to imply
some sort of instantaneous `big bang' beginning. However, this objection is not very
strong: if quasars do not represent past explosions, they provide no evidence against
Hawking's theory.
This understanding of space and time has serious ramifications for versions [A] and [B]
of the cosmological argument. As Hawking points out:
`If the universe is really completely self-contained, having no boundary or edge, it
would have neither beginning nor end. What place, then, for a creator?'
The Question of Contingency
Cosmological arguments of the form [C], above, cannot fall foul of the idea that the
universe may have had no beginning, since they attempt to argue not that the history of
the universe was begun by Divine activity, but that the universe exists only because God
causes it to. If Hawking's model of space-time curvature is a correct understanding of the
universe, arguments [A] and [B] lose their common presumption - that the universe
began. However, argument [C] is untouched by Hawking's theory: why does a spatiotemporally boundless universe exist? Where scientists attempt to understand the `laws of
nature', arguments such as [C] ask why those laws hold.
Argument [C] rests on the idea that the universe exists contingently. That is, it may be
true that the universe is composed of energy-matter consisting in space-time and
exhibiting certain qualities and tendencies, but it is only contingently true: science can
give no ultimate reason why the universe is the way it is, or indeed why it is at all. The
universe could have been different; the universe need never have been. Given the
`principle of sufficient reason', everything that occurs does so for a reason - things do not
`just happen'. A contingent event is an event which need not have occurred. A contingent
event, therefore, occurs only when there is a reason for its occurrence. If it is contingent,
then it must also have a reason for occurring. Ultimately, therefore, the universe exists
due to some necessary being or event, which does not itself have a reason for being.
The central difficulty with this argument concerns its use of the concepts of necessity and
contingency, usually considered to refer to the connection between a subject and a
predicate, but here used to pick out a mode of existence. (For example, the subject
`triangle' has the necessary predicate `has three sides', but it may also have the contingent
predicate `is drawn in red ink'.) Hume insists that matters of fact (i.e., claims that certain
things exist) and relations of ideas (such as predication) are entirely separate and cannot
be combined. On the Humean view, then, there cannot be necessary existence or
contingent existence, since necessity and contingency are relations of ideas, where
existence is a matter of fact. To talk of necessary or contingent existence, on this view, is
as much a category error as the statement: `this idea is yellow'.
Kant offers another reason why existence cannot be necessary: necessity is a relation
between a subject and a predicate, but existence is not a predicate. To say that x exists,
according to Kant, is to say that there is a thing which corresponds to my concept of x. If
existence is a predicate, then an existing thing (e.g., a horse) can never correspond
precisely with the concept of it (e.g., the concept of a horse) - for the concept does not
have the property of existence. Gottlob Frege (1848-1925) held a similar theory: to say
that x exists, according to Frege, is to say that the number of mind-independent objects
that correspond to the concept of x exceeds zero. That is, `x exists' means not that x has
the property of existence, but that there is at least one thing that corresponds to the
concept x.
The logical claims of Hume, Kant and Frege are subject to debate, but it would be a
digression to discuss them further here. This is because Hume, Kant and Frege are all
discussing logical necessity - necessity as a relation between concepts. It has been
claimed that logical necessity is not the only kind of necessity; that a thing can be
`necessary' (in the sense that it could neither be other than it is, nor not be at all) without
being logically necessary. For example, both Aristotle and Aquinas refer to eternal truths
as `necessary', and Kant talks of `factual necessity' - the necessity of the laws of nature.
God has often been characterised as self-dependent. If God is omnipotent, incorruptible,
and indestructible, then it seems that God simply is and cannot not be. There cannot have
been an event in the past that brought God into existence, and there cannot be any event
that would bring it about that God ceases to exist (since either of these would limit the
power of God). This understanding of the nature of God renders God necessary in the
sense of entirely independent of any conditions: since no situation would be God-less,
God cannot not be. This understanding of God can be expressed in terms of Aquinas's
view that God's existence is identical with God's essence, or in terms of the view,
proposed by Paul Tillich (1886-1965), of God as `Being-itself'. Most recently, this view
has been advanced by John Hick, who talks of God's existence as one of aseity (i.e., God
is independent of all that is not God). If God is seen in this way, God's existence can be
understood as necessary in contrast with the contingent (i.e., superfluous, dependent)
existence of the universe and all its contents. Such a view of necessary and contingent
existence ties in well with cosmological arguments of type [C].
Theological Difficulties
There are two major theological difficulties with cosmological arguments. To begin with,
the argument need not conclude in theism, since deism would suffice. Where theists
claim that God is continually involved in the universe, deists claim that God created the
universe and left it to obey its own laws. The cosmological argument concludes only that
God created the universe. In A Brief History of Time, Hawking writes:
With the success of scientific theories in describing events, most people
have come to believe that God allows the universe to evolve according
to a set of laws and does not intervene in the universe to break those laws.
However, the laws do not tell us what the universe should have looked
like when it started - it would still be up to God to wind up the clockwork
and choose how to start it off. So long as the universe had a beginning, we
could suppose it had a creator.
However, theists may counter-argue that the cosmological argument, if it is sound, can be
used to prove also that God sustains the universe in existence. That is, if the question
`Why did the universe start?' is replaced with `Why doesn't the universe stop?', a
cosmological argument may be formulated which will conclude that the universe
continues to exist due to a Divine cause.
The second theological objection concerns the cosmological arguments' characterisation
of God. Argument [A] characterises God as the cause of the universe; argument [B]
characterises God as the cause of all events; argument C characterises God as a necessary
existent, cause of all contingent beings. Cosmological arguments do not lead to the
traditional Western understanding of God as an all-powerful, personal moral authority.
However, it may be argued that the understanding of God as creator is part of the
traditional understanding and does not contradict any of the other traditional divine
attributes; if you can see a long grey trunk protruding from the bushes, there is probably
an elephant attached.
Key Terms
Aseity - To exist a se is to exist independently of any conditions. My existence, for
example, is not a se since there are conditions required for it (e.g., the presence of
oxygen).
Contingency - The opposite of necessity (see below). That John Major is Prime Minister,
for example, is contingent.
Necessity - A thing is said to be `necessary' if it cannot be other than it is. That 2 plus 2
equals 4 is necessarily true, since two plus two could not equal anything else.
Predicate - In Aristotelian logic, a predicate is something that is affirmed or denied of a
subject. For example, in the sentence `Plato is a philosopher', the subject is `Plato' and the
predicate is `being a philosopher'.
Suggested Reading
For a general survey of the issues surrounding cosmological arguments, see:
Brian Davies, An Introduction to the Philosophy of Religion, Rev. ed. (OUP, 1993),
Chapter 5.
For more detailed analysis, see:
J.L. Mackie, The Miracle of Theism: Arguments for and against the existence of God
(Clarendon, 1982), Chapter 5.
Richard Swinburne, The Existence of God. Rev. ed. (Clarendon, 1991), Chapter 7.
For a discussion of the history of the universe, see:
Stephen W. Hawking, A Brief History of Time: From the Big Bang to Black Holes
(Bantam, 1988), Chapter 8.
For a discussion of necessary and contingent existence, see:
R.M. Adams, The Virtue of Faith (OUP, 1987), Chapters 13 and 14.
J. Hick, God and the Universe of Faiths (Macmillan, 1988), Chapter 6.