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Quentin Smith Hawking


Stephen Hawking’s Cosmology and Theism (1994)

 

Quentin Smith

 

The following article was originally published in ANALYSIS in 1994 (Volume 54, No. 4. pp. 236-243).

 

1. Stephen Hawking has recently argued that there is ‘no place for a creator’, that God does not exist. In his quantum cosmology

there would be no singularities at which the laws of science broke down and no edge of space-time at which one would have to appeal to God or some new law to set the boundary conditions for space-time . . . The universe would be completely self-contained and not affected by anything outside itself. It would neither be created nor destroyed. It would just BE . . . What place, then, for a creator? ([9], pp. 136, 141)

This does not seem much like an argument, let alone a rigorous argument, for atheism, and theists have jumped all over it, claiming it blatantly fails as an argument for God’s nonexistence. (See Isham [10], Craig [1], Drees [7], Le Poidevin [11], Deltete [6].) Specifically, they have argued that even if Hawking’s physical laws are true, that fact does not entail that the God of classical theism does not exist or even disconfirm the classical theistic hypothesis.

It seems to me that a case can be made that Hawking’s physical laws are inconsistent with classical theism. I shall develop an argument to this effect in the present paper. Although this argument is not explicit in Hawking’s writings, it is arguably implicit in or based upon his theory. I shall argue that

(P) Hawking’s wave function law obtains

entails

(C) God does not exist.

Some defenders of classical theism have not attacked (P) but have attacked the claim that (P) entails (C). It is not part of my argument to defend (P), although I believe (P) is confirmed by observational evidence, e.g. by the COBE satellite observations of the density fluctuations in the background radiation, by the observed large-scale homogeneity and isotropy of the universe, by the evidence for an early inflationary era, and by the evidence that the critical density is near to one.

2. Hawking’s atheistic dreadnought is a ‘wave function of the universe’. The wave function is Psi[hij,Phi]. Without bothering overly much about technical niceties, we may take Phi as representing the matter field of the initial state of the universe, roughly, how much matter this state contains and how it is distributed. hij may be regarded as representing the metrical structure of the initial state of the universe, that is, the sort of curvature possessed by the three dimensional space of this state. [Note: For a technical discussion of Hawking’s quantum cosmology, see Quentin Smith, ‘The Wave Function of a Godless Universe’ in [20]; also see Smith and Grunbaum [21].] Psi is the amplitude, which is important since the square of the modulus of the amplitude gives a probability, namely, the probability that the universe will begin to exist with the metric hij and the matter field Phi.

The square of the modulus of the amplitude is |Psi[hij,Phi]|2. As Hartle and Hawking say, this gives us the probability ‘for the Universe to appear from nothing’ ([8], p. 2961), specifically, it gives us the unconditional probability that a universe begins to exist with the metric hij and matter field Phi. The reason this equation is inconsistent with classical theism is related to the respect in which quantum cosmology has superior explanatory value to classical general relativistic cosmology (the ‘standard hot big bang model’). According to the standard hot big bang model, the universe began to exist about 15 billion years ago from a physical singularity, the big bang singularity. At this singularity, all physical laws break down and thus it is in principle impossible to predict what will emerge from the singularity. Furthermore, the existence of the singularity itself is an unexplained given. [Note: This assumes a realist interpretation of the big bang singularity; for further discussion see Smith [13], [14], [15], [16], [18], [19].] Hawking’s quantum cosmology omits the initial singularity and implies that it is probable (to a degree less than one) that the universe begins to exist with a nonsingular state, namely hij,Phi, in accordance with the wave function law Psi[hij,Phi].

3. It is precisely this implication that precludes the existence of God. Let us suppose (for the sake of illustration) that the probability value the wave function gives us is 95%. The wave function law would then entail:

(1) The probability that a universe begin to exist with the metric hij and matter field Phi is 95%.

Now consider the hypothesis that God ordains that Hawking’s wave function law obtains. Assuming this hypothesis, God could create the sort of universe that is most probable or the one that is second most probable, etc., as specified by the law he chose to make obtain. Suppose he decides to create the most probable one. It follows that the universe has a sufficient condition of its existence, not a probabilistic one. Note that

(2) God wills that a universe begin to exist with a metric hij and matter field Phi.

entails

(3) The probability that a universe begin to exist with the metric hij and matter field Phi is 100%.

God is omnipotent and thus his willing cannot fail to be effective and thus the probability value is 100%. Now (3) is inconsistent with (1). Since (1) is true if Hawking’s wave function law obtains and (2) entails (3), it follows that (2) is false if Hawking’s wave function law obtains. Put another way, it is implicitly self-contradictory that

(4) God wills that Hawking’s wave function law obtains and that a universe begin to exist with the metric hij and matter field Phi,

since if the law obtains, the probability is 95%, and if God wills that this universe exist, the probability is 100%.

Suppose the defender of classical theism responds that (1) really means

(5) The probability that a universe begin to exist without supernatural causation and with the metric hij and matter field Phi is 95%.

and that the probability estimate stated in (3) is more explicitly stated by

(6) The probability that a universe begin to exist with the metric hij and matter field Phi, given that God wills such a universe to begin to exist, is 100%.

Since (5) is consistent with (6), it follows that (1) is consistent with (2) and thereby that Hawking’s quantum cosmology has a place for a creator.

However, this response conflicts with the various propositions entailed by classical theism. Classical theism is the theory that there necessarily exists a disembodied person who is necessarily omniscient, omnipotent and omnibenevolent and necessarily the cause of whatever universe there is. Accordingly, classical theism entails

(7) Necessarily, there is no universe that begins to exist without supernatural causation.

Given (7), it is true that, in the absence of supernatural causation, the probability that a universe begins to exist with the metric hij and matter field Phi is 0%. If the wave function is ‘the amplitude for the Universe to appear [supernaturally uncaused] from nothing’ and the modulus of the amplitude squared gives the probability, then the probability contra Hartle and Hawking is zero if it is true that the universe cannot begin to exist supernaturally uncaused.

Thus, if Hawking’s wave function law obtains, there is ‘no place for a creator’ and classical theism is false. Indeed, if it is even possible that the wave function law obtains, classical theism is false, since classical theism entails that there is no possible world in which a universe begins to exist supernaturally uncaused. Accordingly, we should conclude that theists are mistaken if they think that Hawking’s quantum cosmology is consistent with classical theism.

4. The fact that classical theism is inconsistent with Hawking’s cosmology does not entail that every version of theism is inconsistent with this cosmology. I shall discuss acausal and causal versions of nonclassical theism and determine the respects in which they are consistent with the obtaining of the wave function law.

An acausal version of nonclassical theism may include the proposition that God is responsible for instituting the laws that govern whatever universe exists, but that God does not create the universe. In the actual world, God wills that the wave function law obtains but does not will that the universe exist. Rather, God leaves it to chance, a 95% chance, that the universe with the specified metric and matter field will begin to exist uncaused.

It is important to emphasize that this version of theism, although consistent with Hawking’s cosmology, is fundamentally at odds with central tenets of classical theism and is even more dissimilar to classical theism than is deism. It is central to classical theism and deism that God is the cause of the universe. This tenet is inconsistent with acausal theism, since according to acausal theism the universe is not created by God but instead came into existence uncaused in accordance with a probabilistic law. On the acausal version of theism, God does not will that some concrete objects exist but merely that some abstract object possesses a certain property; God wills merely that the wave function law has the property of obtaining. If God wills that this law obtain, there is a 100% probability that it obtain and if it obtains, there is a 95% chance that a universe with the metric hij and matter field Phi will come into existence uncaused.

Acausal theism also rejects the classical doctrine of continuous creation (divine conservation). As Phillip Quinn represents this theory, it holds that ‘God not only creates the cosmos of contingent things but also conserves it in existence at every instant when it exists’ ([12], p. 55). The rejection of this doctrine is motivated by considerations similar to the rejection of the doctrine that God causes the universe to begin to exist. Hawking’s wave function law enables the probabilistic history of the universe to be calculated once the initial state of the universe is known. Given the initial state, we have certain probability values (each less than 100%) for possible subsequent states and histories of the universe. This is inconsistent with continuous creation, since God’s willing of any state or history is guaranteed to be effective and thus the probability value of any state or history he willed would be 100%. If God willed that some subsequent state, say S, follow upon the initial state, then the existence of S would have the probability of 100%, inconsistently with the wave function law, which gives the existence of S a probability less than 100%. According to acausal theism, God does not continuously create the universe but instead leaves it to chance (specifically, the chances specified by the wave function he ordained to obtain) as to whether the universe will continue existing and as to which state will follow upon a prior state. Once the wave function law is decreed to obtain by God, a probability distribution for possible histories of the universe is determined and God sits back and watches as chance takes its course.

5. The classical theist may resist the suggestion that she must retreat to an acausal version of theism in order to retain a theistic belief that is consistent with Hawking’s cosmology. It may be argued that a central tenet of classical theism, that God is actually the original and continuous creator of the universe, may be retained consistently with the obtaining of Hawking’s wave function law if we reject the idea that God necessarily exists and the idea that it is a necessary truth that every thing that begins to exist has a cause. According to this causal version of nonclassical theism, God actually causes the universe to begin to exist but there is some possible world in which God does not exist and in which there is a universe that begins uncaused. Alternatively, the theist could retain the idea that God actually causes the universe and necessarily exists but reject the idea that he necessarily causes the universe; according to this version, there is some possible world in which God exists but in which the universe begins to exist uncaused. Each of these two causal versions of nonclassical theism is arguably consistent with Hawking’s cosmology since we cannot infer from either of these two versions that

(7) Necessarily, there is no universe that begins to exist without supernatural causation,

and thus cannot infer that the probability of a supernaturally uncaused universe is 0%. Since the possibility of an uncaused universe is granted, these versions of theism are consistent with

(5) The probability that a universe begin to exist without supernatural causation and with the metric hij and matter field Phi is 95%.

The key to these causal versions of nonclassical theism is the argument that (5) is true even if the universe actually begins to exist by supernatural causation. The truth of (5) may be explained in terms of a quantification over merely possible worlds, namely, in terms of the assertion that a universe with the metric hij and matter field Phi begins to exist uncaused in 95% of all the possible worlds in which the wave function law obtains and in which it is not the case that God causes a universe to exist. This is consistent with the claim that in 100% of the possible worlds in which God wills that such a universe begin to exist, it does begin to exist, and with the claim that the actual world is one of these worlds. Hartle and Hawking may have believed that in the actual world, the universe begins uncaused, but this proposition is not entailed by their wave function law. Their law states the probability of the universe beginning to exist under the condition that the universe not be supernaturally caused, but this condition is not met in the actual world, at least according to the causal versions of nonclassical theism.

However, this attempt to preserve God’s classical role as the cause of the universe is inconsistent with two of the divine attributes, viz., the rationality and goodness of God.

If God is rational, then each law instituted by God is instituted for a reason. The conjunction of either of the two causal versions of nonclassical theism with Hawking’s cosmology is inconsistent with the rationality of God since this conjunction implies that God ordains that the wave function law Psi[hij,Phi] obtain but that God has no reason for ordaining that it obtain. There is no reason for instituting a law that makes it 95% probable that a universe with the metric hij and matter field Phi will come into existence uncaused, under the condition that God not will that this universe come into existence, if God intends to bring this universe into existence by his will and thereby vitiate the condition laid down in the law.

A second respect in which the hypothesis that God actually causes the universe is problematic is that it is inconsistent with God’s goodness. There is abundant observational evidence that confirms the hypothesis that the universe began to exist uncaused in accordance with Hawking’s wave function law. The early inflationary era, the density fluctuations in the background radiation discovered by the COBE satellite, the large scale homogeneity and isotropy of the universe, the fact that the universe is nearly flat, etc., all confirm the hypothesis that the universe began uncaused in accordance with Psi[hij,Phi]. If God nonetheless caused the universe to begin to exist, he would have created a universe that appeared to come into existence by virtue of a scientific law but in reality did not come into existence in this way. This would constitute a deception of human beings and would defeat the quintessentially human project of rational scientific inquiry. We would have a situation analogous to Descartes’ scenario about the evil demon, who deceives human beings by making it delusively appear as if there is an external world. However, God is good, as Descartes noted, and thus would not deceive human beings.

6. For these two reasons, the endeavor to preserve God’s classical theistic role as original and continuous creator the universe cannot succeed. If there is a theism consistent with the obtaining of the law Psi[hij,Phi], it must be an acausal theism.

But the fact of this consistency does not show there is a positive reason to believe that acausal theism and Hawking’s wave function are both true. In order to establish this, one would have to show that the wave function law Psi[hij,Phi] obtains because some mind wills it to obtain. But it is hard to see how this could be shown. Clearly, that Psi[hij,Phi] obtains does not entail that some mind wills Psi[hij,Phi] to obtain. Furthermore, there seems to be no empirical evidence that would confirm the conjunction of acausal theism and the wave function law to an equal or greater degree than it would confirm the wave function law alone. The anthropic coincidences (see Smith, [17]) and the existence of intelligent organisms do not count as separate evidence for theism, since these are predicted by the wave function law. As Hawking writes, ‘Each history in the sum over histories will describe not only the space-time but everything in it as well, including any complicated organisms like human beings who can observe the history of the universe. . . .[Calculations show] that, using the sum over histories, our universe is not just one of the possible histories but one of the most probable ones.’ ([9], p. 137) Accordingly, there seems to be no logical or empirical reasons to support a belief that there is a deity who instituted the wave function law. It seems we are left with the belief that Psi[hij,Phi] alone is responsible for the existence of the universe. [Note: I should like to thank an anonymous referee for Analysis, William F., Vallicella, Christopher Isham and the Department of philosophy at Western Michigan University for helpful comments on earlier versions of this paper.]

Western Michigan University

Kalamazoo, MI 49008, USA

References

[1] William Lane Craig, "’What place, then, for a creator?": Hawking on God and Creation’, British Journal for the Philosophy of Science 41(1990) 473-91.

[2] William Lane Craig, ‘Theism and Big Bang Cosmology’, Australasian Journal of Philosophy 69 (1991) 492-503.

[3] William Lane Craig, ‘God and the Initial Cosmological Singularity: A Reply to Quentin Smith‘, Faith and Philosophy 9 (1992) 238-48.

[4] William Lane Craig, ‘The Origin and Creation of the Universe: A Reply to Adolf Grunbaum‘, British Journal for the Philosophy of Science 43 (1992) 233-40.

[5] William Lane Craig, ‘The Caused Beginning of the Universe: A Response to Quentin Smith‘, British Journal for the Philosophy of Science 44 (1993) 623-39.

[6] Robert J. Deltete, ‘Hawking on God and Creation’, Zygon 28 (1993) 485-506.

[7] W. B. Drees, Beyondthe Big Bang (La Salle: Open Court, 1990)

[8] J. Hartle and S. W. Hawking, ‘Wave Function of the Universe’, Physical Review D 28 (1983) 2960-75.

[9] S. W. Hawking, ABrief History of Time (New York: Bantam, 1988).

[10] Chris Isham, ‘Creation of the Universe as a Quantum Process’, in Physics,Philosophy, and Theology, ed. R. J. Russell et al. (Notre Dame: Notre Dame University Press, 1988).

[11] Robin Le Poidevin, ‘Creation in a Closed Universe Or, Have Physicists Disproved the Existence of God?’, Religious Studies 27 (1991) 39-48.

[12] Phillip Quinn, ‘Divine Conservation, Continuous Creation, and Human Action’, in TheExistence and Nature of God, ed. A. Freddosa (Notre Dame: University of Notre Dame Press, 1983).

[13] Quentin Smith, ‘The Uncaused Beginning of the Universe‘, Philosophy of Science 55 (1988) 39-57.

[14] Quentin Smith, ‘A Natural Explanation of the Existence and Laws of Our Universe‘, Australasian Journal of Philosophy 68 (1990) 22-43.

[15] Quentin Smith, ‘Atheism, Theism and Big Bang Cosmology‘, Australasian Journal of Philosophy 69 (1991) 48-66.

[16] Quentin Smith, ‘A Big Bang Cosmological Argument for God’s Nonexistence‘, Faith and Philosophy 9 (1992) 217-37.

[17] Quentin Smith, ‘The Anthropic Coincidences, Evil and the Disconfirmation of Theism‘, Religious Studies 28 (1992) 347-50.

[18] Quentin Smith, ‘Did the Big Bang Have a Cause?’, British Journal for the Philosophy of Science 45 (1994) 649-668.

[19] Quentin Smith, ‘Did Everything Come to Be Without a Cause?’, Dialogue: Canadian Philosophical Review, forthcoming.

[20] Quentin Smith and William Lane Craig, Theism, Atheism and Big Bang Cosmology (Oxford: Clarendon Press, 1993).

[21] Quentin Smith and Adolf Grunbaum, The Uncreated Universe (New York: Oxford University Press, forthcoming).