Where the Conflict Really Lies: Science, Religion, and Naturalism (13 page)

Of course we have been thinking about
classical
science. What happens if we turn to contemporary science, in particular quantum mechanics? Will we find conflict there? That’s the subject for
chapter 4
.

In
chapter 3
we saw that many theologians, scientists, and philosophers hold that special divine action in the world—causing a miracle, for example—is incompatible with science. I argued that this claim together with the hands-off theology to which it gave rise is no doubt popular, but it suffers from a common if unhappy condition: it is wholly mistaken. That is, it is mistaken with respect to classical science, the physics of Newtonian mechanics, and of electricity and magnetism. It is the Laplacean picture that is incompatible with special divine action, but the Laplacean picture with its causal closure of the physical universe is really a piece of metaphysics unsupported by classical science. As everyone knows, however, the old Laplacean (and Newtonian) scientific picture has been superseded—by two large-scale, indeed stunning revisions. First, there is relativity theory, both special and general; second, and crucial for our purposes, there is quantum mechanics; both have been with us since the second or third decade of the twentieth century. As I noted above, there is an interesting irony in these theologians urging the deterministic, Laplacean picture, when that picture is no part of the classical science to which they solemnly pledge fealty. There is a further irony: the classical science they so eagerly meant to accommodate was well out of date at the time they were eagerly accommodating it. In this chapter I’ll argue that quantum mechanics offers even less of a problem for divine special action than classical science, even though the latter doesn’t offer much of a problem.

So what about current science, in particular quantum mechanics (QM)?
¹
How does it stand with respect to the question of special divine action in the world? This is not the place to outline the essentials of QM, even if that were within my powers; let me just recommend “Distilling Metaphysics from Quantum Physics” by Tim Maudlin.
²
Still, a few remarks about it are essential to the current project. QM is characterized by several substantial departures from classical physics; of these, only
indeterminism
is relevant to our present concerns. Classical mechanics is deterministic in the following sense. Suppose you are given an initial configuration of a material system—that is, a system of particles together with their positions, masses and velocities—at a time
t
. Now consider any time
t*
future with respect to
t
; if the system is causally closed, there is just one outcome consistent with classical mechanics. It may be impossible to calculate the outcome—indeed, as mentioned above, we don’t have analytic solutions for the “
n
-body problem” where
n
is greater than 2; nevertheless, for any
t*
only one outcome is permitted by classical mechanics.
³

Things are very different for QM. The Schrödinger equation for a system
S
—a system of particles, for example—associates a wave
function with
S
; in essence, for any future time
t
, the wave function assigns a complex number to each of the many configurations possible for
S
at
t
. This wave function is used (via “Born’s Rule”) to assign a certain probability to each possible configuration
c
for
S
at
t
: the probability of finding
S
in
c
at
t
. The point, here, is that (in contrast with classical mechanics) we don’t get a prediction of a unique configuration for the system at
t
, but only a distribution of probabilities across many possible outcomes. Given a quantum mechanical system, therefore, QM doesn’t say which configuration will
in fact
result from the initial conditions; instead, it assigns a spectrum of probabilities to the possible outcomes. If our system consists in a single particle, for example, QM doesn’t tell us where that particle will be found at a subsequent time
t*
, but (via Born’s Rule) only gives us probabilities for its location then.
⁴
(Strictly speaking, it could be anywhere, although of course for most locations the probability of its being there then will be infinitesimal.)

QM as such, therefore, does not support the Laplacean picture: many different positions for that particle at
t*
are consistent with the laws of QM together with its position at
t
; for a system of particles, many different configurations at
t*
are consistent with the laws together with its configuration at
t
. Hence not even someone as talented as Laplace’s demon (
chapter 3
, section IIB) could predict the physical condition of the universe at future times, even if she is given the laws along with a maximally determinate description of the
universe at
t
. It is this indeterminism that has led people to say that, according to QM, it is possible (however unlikely) that all the particles in my body (and hence my body itself) be on one side of a wall at
t
, and at
t*
as close as you please to
t
, these particles (and hence my body) be on the other side of that wall. In the same vein, so we are told, QM permits the equestrian statue of Robert E. Lee in Richmond, Virginia, to leap from its pedestal and gallop off into the distance, waving its hat and bellowing the rebel yell.

We saw earlier (
chapter 3
, section IIA) that the classical laws of mechanics and conservation of energy come with an implicit proviso: they apply
when the relevant system (the universe, for example) is causally closed
. The same proviso holds, substantially, in the case of QM: the laws apply to causally closed systems. But even if we ignore this proviso, special divine action, including miracles, is by no means incompatible with QM.
⁵
That is because (again) QM doesn’t determine a specific outcome for a given set of initial conditions, but instead merely assigns probabilities to the possible outcomes. This means that, even apart from that proviso, QM doesn’t constrain special divine action in anything like the way classical deterministic mechanics does.

Clearly QM doesn’t prohibit divine providential action and answers to prayer; what about such stunning miracles as walking on water, raising the dead, changing water into wine, parting the Red Sea, miraculous healings, and so on? Here, since I am not a quantum mechanic, I am reduced to arguing from authority. According to the expert opinion to which I have had access, some of these (parting the Red Sea, miraculous healings) are unproblematically compatible with QM. On other miracles, however—for example, raising the dead, and transmutation, as with changing water into wine—there seems
to be substantial difference of opinion among the experts. Little analysis of these kinds of cases has been published; but some of the experts I’ve talked with—Katherine Brading, Craig Lent, Bas van Fraassen—think it implausible that QM is compatible with these miracles. Others, for example John Earman and Bradley Monton, think QM is compatible with them. Thus Earman:

If we try to define a miracle as an event that is incompatible with (what we presume, on the basis of the best evidence, to be) laws of nature, then it seems that water changing to wine, a dead man coming back to life, etc. are not miracles because they are not incompatible with QM. But QM does say that they are very, very improbable.
⁶

And according to Monton,

For what it’s worth, I think that all the miracles are pretty unproblematically compatible with the GRW theory. The wave function for each particle is spread throughout an unbounded region of the universe, at every time (except perhaps momentary instants of time). This means that for each particle, there is at most a finite region where it couldn’t be localized by a GRW hit. (For some (probably even most) particles, they could be localized anywhere.) So for changing water into wine, it’s not a big deal—you’ve got a bunch of individual particles (electrons, protons, etc.) that are composing the water, and they can all have GRW hits such that their positions are redistributed to the locations that would be appropriate for them to compose wine. Since there’s at most a finite region of the universe where these particles can’t show up, and there’s no reason to expect the finite
regions for the different particles to overlap in any special way, the particles can all appear in the positions appropriate for them to compose wine.
⁷

Monton is speaking of the Ghirardi-Rimini-Weber (GRW) approach to quantum mechanics (discussed in more detail later in this chapter); presumably a similar point would apply to the classical Copenhagen interpretation. So the first thing to see here is this: it is far from clear that QM, even bracketing the proviso according to which the laws apply to closed systems, is incompatible with miracles. And if what happens in the physical world at the macroscopic level supervenes on or is determined by what happens at the microlevel—the quantum level—then if miracles are compatible with the laws of quantum mechanics, they will also be compatible with any macroscopic laws.

On the “new picture,” therefore—the picture presented by QM—there is no question that special divine action is consistent with science; and even the most stunning miracles are not clearly inconsistent with the laws promulgated by science. One might therefore expect that the whole concern about special divine action would disappear. If one did, however, one would be sadly disappointed. The fact is many philosophers, theologians and scientists—thinkers who are wholly aware of the QM revolution—still apparently find a problem with miracles and special divine action generally. Rudolph Bultmann, Langdon Gilkey, John Macquarrie, and their friends rejected divine intervention in the name of an eighteenth-century picture of science; many contemporary writers on religion and science also reject divine intervention—not, now, by appealing to outmoded science, but for other more obscure reasons. I shall argue two points: first, that their reasons for rejecting intervention are no more cogent than those of Gilkey and others. And second, I’ll argue that,
given contemporary quantum physics, there isn’t any sensible way to say what intervention
is
, let alone find something in science with which it is incompatible.

First, however, we need a representative sample of contemporary thinkers in this area who reject intervention. An excellent exhibit is “the Divine Action Project” (DAP), a multi-year series of conferences and publications that began in 1988.
⁸
So far these conferences have resulted in five or six books of essays involving some fifty or more authors—scientists, theologians, philosophers—including many of the most prominent writers in the field: Ian Barbour, John Polkinghorne, Arthur Peacocke, Robert Russell, Thomas Tracy, Nancey Murphy, Philip Clayton, and many others. This is certainly a serious and impressive attempt to come to grips with the topic of divine action in the world. Nearly all of these authors believe that a satisfactory account of God’s action in the world would have to be
noninterventionistic
(and to begin with, let’s suppose we have a good idea as to what intervention is). It would be fair to say, I think, that the main problem for the project is to find an account of divine action in the world—action beyond creation and conservation—that doesn’t involve God’s intervening in the world. Thus the late Arthur Peacocke, one of the most prominent members of this project, comments as follows on a certain proposal for divine action, a proposal according to which God’s special action would be undetectable:

God would then be conceived as acting, as it were, ‘within’ the flexibility we find in these (to us) unpredictable situations in a way that could never be detected by us. Such a mode of divine action would never be inconsistent with our scientific knowledge of the situation….. God would have to be conceived of as actually manipulating micro-events (at the atomic, molecular, and according to some, quantum levels) in these initiating fluctuations on the natural world in order to produce the results at the macroscopic level which God wills.

But such a conception of God’s action… would then be no different in principle from that of God
intervening
in the order of nature with all the problems that that evokes for a rationally coherent belief in God as the creator of that order. The only difference… would be that… God’s intervention would always be hidden from us.
⁹

What
are
the problems evoked “for a rationally coherent belief in God as the creator of that order”? Why should we expect God to avoid intervention? Philip Clayton, one of the authors in this group, puts it as follows: “the real problem here, apparently, is that it is very difficult to come up with an idea of divine action in the world in which such action would not constitute ‘breaking natural law’ or ‘breaking physical law.’”
¹⁰
But can this be right? As we’ve seen, it is extremely hard to “break”
quantum mechanical laws—even with the “when the universe is causally closed” proviso deleted. And in any event the whole notion of “breaking” a natural law seems confused, as I argued earlier. Wesley Wildman proposes a more promising problem for intervention:

The DAP project tried to be sensitive to issues of theological consistency. For example, the idea of God sustaining nature and its law-like regularities with one hand while miraculously intervening, abrogating or ignoring those regularities with the other hand struck most members as dangerously close to outright contradiction. Most participants certainly felt that God would not create an orderly world in which it was impossible for the creator to act without violating the created structures of order.
¹¹