Science in Christian Perspective
The Mind-Body Problem:
Scientific or Philosophic?
Implications for Apologetics
THOMAS J. BURKE
Department of Philosophy and Religion
Hillsdale, Michigan 49242
From: JASA 36 (March 1984): 13-18.
This paper analyzes the arguments for dualistic interactionism given by Karl Popper in The Self and Its Brain and those presented on behalf of the identity theory by D. M. Armstrong in A Materialist Theory of the Mind. It is concluded that none of the arguments put forth by the disputants are truly scientific in nature, despite the claims to the contrary, because both positions are compatible with all the evidence cited. The problem, therefore, is not scientific, but philosophic. The logic of this problem, it is then argued, is isomorphic with that of God's relationship to the world. Consequently, empirical events of whatever sort imaginable can have evidential value only in conjunction with a verbal message arising in an historical context relevantly preparatory to both the events and the accompanying message. It is concluded that strictly scientific evidence for Theism is not possible, but belief can and ought to be rationally warranted.
In his 1977 work, The Self and Its Brain,1 co-authored with Sir John Eccles, Karl Popper argues in favor of a dualist ontology, positing both a material world and a world of nonmaterial, mental events. He begins by delineating 3 worlds. World I is the world of physical objects, world 2 that of subjective experience, and world 3 is composed of "the products of the human mind."2 A prime example of world 3 objects are scientific theories. They are embodiable in worlds 1 and 2 objects, (books, for example), but are not identical with them. World 3 objects are not reducible to world 1 or 2 objects, but can exist, and, essentially, do exist, unembodied. They are abstract. Yet, he argues, we know they exist because through the medium of world 2 objects they have observable effects on world I objects. Popper then goes on to argue that minds cannot be mere material objects, for only nonmaterial minds could invent, grasp, and use abstract, nonmaterial, world 3 objects.
D. M. Armstrong, in a book predating Popper's,3 has set forth a number of arguments for materialism and against mind-brain dualism. While both Popper and Armstrong muster divergent philosophical arguments for their respective cases, they have one major feature in common: both perceive the mind-brain problem as capable of scientific resolution. Either the mind will be fully explicable in terms of brain states, as Armstrong holds, or the positing of a nonmaterial mind will be scientifically necessary to fully account for our knowledge of the world, as Popper and Eccles believe. Presumably, then, if brain science could be shown to fully account f or Popper's worlds 2 and 3, Popper and Eccles would give up their dualistic position and accept physicalism; likewise, if future scientific inquiry were only possible on the supposition of a nonphysical mind, Armstrong would forsake physicalism for dualism. In the eyes of the disputants, then, Dualism and Identity Theory are two rival scientific theories. Both parties recognize that our knowledge of the brain has not progressed to the point where these competing theories are capable of precise formulation and exact testing, and, therefore, neither can at this point be definitely falsified. They might better be considered rival research programs or scientific paradigms by which f uture research should be guided and within which it should take place. But even if exact mathematical precision forever escapes both "theories, I I eventually, they feel, one or both would come up against experience for which it (they) could not account and would be falsified. For Popper, unless some startling new and totally unexpected discoveries are made, this is already the case for physicalism, i.e., it has already been faced with data for which it cannot give any adequate account. Armstrong, however, believes a physicalistic account of mental experience is not only possible, but scientifically more respectable given our present knowledge. The burden of proof, he feels, is on the dualist to demonstrate some aspect of mental life for
A 'mind-of-the-gaps' theory is no better than a 'God-of-the-gaps' theology.
Our analysis of this debate will lead us to the conclusion that the problem is not resolvable through scientific method, but that both positions nevertheless do assert different things, and that both are meaningful attempts to account for the world. It will then be argued that the nature of this problem is paradigmatic f or the relationship of God to the world and that similar difficulties arise when trying to account for events in the physical world from a theistic or from. a materialistic perspective. An attempt will be made to show that the theist-materialist argument is unresolvable through the scientific method for reasons analogous to those which I vitiate a scientific resolution to the mind-body problem. Accordingly, some definite implications for apologetics will result.The Inherent Inconclusiveness of Scientific Evidence for Mind
Popper's first move is to trace the development of physical science through the "push theory" of Descartes, the "pull theory" of Newton, and the electron theory of Thomson, until the modern theory of physical reality is arrived at, which theory, he stresses, virtually gives up "the idea of substance or essence."4 He concludes, "The universe now appears to be not a collection of things, but an interacting set of events or processes. "5 Materialism, Popper holds, has transcended itself, and no longer can the world be construed in the mechanistic terms of past centuries. The idea of substance and its materialistic counterpart, elementary particles, must give way to the more abstract concepts of processes and events.
This argument, however, does not necessarily lead to a rejection of materialism. The adjustments that need to be made can just as easily be interpreted as a more sophisticated materialism. If one examines Popper's discussion of "the real" closely, an ambiguity arises which is due to this possibility of an alternative interpretation in materialistic terms. To be real, Popper asserts, an entity "should be able to exert a causal effect upon the priam facie real things; that is, upon material things of an ordinary size."6 He continues by adding that such entities, though not directly observable, ought, on the basis of indirect evidence, (e.g., effects on photographic emulsions), to be accepted as really existing. That is, they are not to be construed as mere convenient fictions. Some of these "entities " he notes, are "more abstract" than others, e.g., force fields.7 He goes on to give a dispositional account of such things. "Forces and fields of forces are attached to material things, to atoms, and to particles. They are of a dispositional character: they are dispositions to interact.8
It soon becomes unclear, however, whether the "ultimately real" is the material entities and force fields are "abstract attributes" of these ultimates, or whether the abstract forces are the "really real" and material things are simply special forms of processes of these fields. Popper, it seems, would like to leave that question open to future scientific theorizing. Importantly, however, at this juncture the physicalist need only point out that in either case force fields and like "abstract" posits of modern physics, while not material in the older, crass sense of the word, are nevertheless not "nonmaterial" in the spiritual sense. They are either "attributes of," 11 relations between," "alternative forms of," or some such other construal of material entities. As such, they are part of physical reality. "Ultimate physical reality" is now simply conceived as a physical reality of such things as force fields and energy which, through a favorable concourse of events, can form what to us appear as physical entities such as bodies. That is, bodies, atoms, etc. are merely very "compact" organizations of what were previously thought of as immaterial forces. Energy can now be conceived as an alternative form of matter and matter as an alternative form of energy. Which is "really real" becomes a moot point. One need not hold that we have now come across a nonmaterial reality, but only that material reality is much more complex and multivaried in form than previously thought.
Armstrong would be quite happy with such an account of reality, for we would still not need to posit the existence of "entities" or "things" which have no necessary relationship to the physical at all, are not measurable in any sense, and cannot become a part of scientific theory. If Popper is willing to grant that the mental properties he dubs "nonmaterial" can become a functioning part of modern scientific theory, Armstrong will simply call them physical, and the dispute will then be merely verbal: should we or should we not label these particular theoretical entities physical or nonphysical.It seems, then, that Armstrong has Popper in an extremely unfavorable position. If Popper can show good physical evidence which warrants the positing of nonmaterial entities, the reality of these "entities" becomes such that they can be included under the category of the physical. The fact that they stand in relation to such physical evidence brings them under the category of the physical. Popper's argument based upon the self -transcendence of materialism is, then, not even a good analogical argument, for the type of entities physical science has had to posit are not "nonmaterial," but a new sort of material (physical) thing. Science has not transcended the physical universe and thence found it necessary to deal with " metaphysical" or "theological" realities to explain physical reality. it has merely expanded our conception of physical reality and shown it not to be the sort of hard and firm aggregate of things we once thought it to be.
At this point it should be stressed that the difference
between Popper and Armstrong here is not "scientific" but
conceptual. it is more a question of what we are going to call
things, how they relate to our concepts and our language.
Both men spurn the importance of what they call mere
conceptual or linguistic analysis in this "scientific" dispute.
The above analysis has shown, however, that at least to this
point there is little conceptual clarity about what is really
meant by the material or physical and the nonmaterial. But
until such clarity is achieved, how can we know what will
really count as evidence for or against physicalism or dualism? No scientific investigation is going to tell us that, and so
it becomes unclear and uncertain that Popper and Armstrong's claim that the dualist-identity theory debate is
susceptible of resolution by means of science is at all tenable.
Mind and Emergent Properties
This same difficulty arises with Popper's second line of argumentation. He argues quite cogently that we find in nature emergent laws that are not reducible to laws governing lower levels of structural organization. He stresses the apparent inability of the reductionist program to account for all physical events. He argues not only that the reduction of all science to physics has not yet been done, but that it could not possibly be done. He is at pains to point out that many macro structures are not only not completely explicable in terms of their subsystems, but that the macro structures as a whole can act upon their "constituent elementary particles. " He uses the simple example of a wedge. When used, he notes, "we do not arrange for the action of its elementary particles, but we use a structure, relying on it to guide the actions of its constituent elementary particles to act, in concert, so as to achieve the desired result.9 Stars, he notes, are another example of macro objects which have effects upon the particles of which they are constructed. Such examples are excellent arguments of a two-way interaction between macro structures and the micro structures of which they are composed and, consequently, for the doctrine of emergentism. Laplacian, deterministic reductionism of all physical action to the action of the elementary constitutents of reality would seem highly unlikely, if not impossible. Popper's theory of two-way interaction between different structural levels of reality in accordance with emergent laws appropriate to each level would seem much better equipped to account for the complexity of the world than Armstrong's physical-chemical reductionism.
However, Armstrong could accept emergentism as long as it does not posit nonmaterial substances or processes, and so far, Popper does not. Armstrong writes,
one can hold that certain processes in the central nervous system operate according to emergent laws, laws that cannot be deduced, even in principle, from the laws of physics and chemistry. As a result, behaviour occurs that could not be produced by something working according to purely physico-chemical principles. Such a view would still be a Materialism, for it would not demand any emergent qualities, still less an emergent substance, but it would not be a physico-chemical Materialism."10
New arrangements of atoms may indeed result in properties "not derivable from a statement describing the arrangement of the atoms, combined with a statement of atomic theory,"11 but for Armstrong, they are still properties of physical objects. Again, he writes,
If new basic principles for physics could explain, and could predict, ordinary ... phenomena at least as well as those currently accepted, and if in addition they were able to predict the anomalous behaviour of the central nervous system, then we could switch to the new physics in the interest of a unified scheme of explanation.12
Thus, unless Popper can show that nonmaterial entities or processes are necessary, and in addition show that they are truly not material in the broadest sense of the word, he cannot refute materialism, but only cause its modification. Finally, it has also become apparent that these initial arguments of Popper's are not even good analogical arguments because he
has not established a definite nonmaterial analogue for the mind. Force fields and emergent laws are still capable of physicalistic interpretation.
No purely scientific evidence for God's existence or the nature of His attributes can possibly arise.
In world 3 objects, Popper has what we might call Vrima facie "objects" which are not mere physical objects. As he points out, while they can be embodied in world 1, they are not reducible to world 1 objects. A theory, for example, can be expressed by certain marks on a piece of paper or a chalkboard, but the marks are not the theory. Moreover, Popper argues that some world 3 objects can and do exist unembodied, e.g., mathematical facts such as unthought of numbers, the as yet underived logical implications of theories.
Armstrong would, no doubt, seek to analyze these in terms
of physical things. For example, he might say that unthought
of numbers do not exist until someone thinks of them;
scientific theories exist only insofar as they are expressed in
physical reality, written or spoken, or in brain states
(thoughts); the abstract processes of arguing, theorizing, etc.
exist only as a succession of brain states or insofar as they are
But note, first, that he can give only an analysis of these in of Quinton, physicalistic terms, not a scientific proof. Popper's arguments for a dualistic interpretation and Armstrong's arguments for a physicalistic one are both analyses, not scientific proofs. Not only is current scientific evidence neutral in regard to either
interpretation, but it is difficult to conceive of scientific evidence that would not be. Second, Armstrong's analysis seems far from adequate. Popper has put forth facts of experience for which no purely physicalistic analysis can fully account. Third, these "facts," while open to public scrutiny, do not necessarily imply Popper's dualistic construal. The fact that they cannot be adequately analyzed in materialistic terms does not mean that we must posit a second sort of nonmaterial thing which does account for them. The problem
again goes back to Popper's ambiguous definition of "real." Certainly, theories, works of art, and other world 3 objects have effects upon world I objects through the mediation class with other "intangible" posits which can onl observed indirectly, e.g., electrons. As shown above, el are still physical things (as are force fields), predictions them (within the limits of quantum mechanics) can be they can be quantified, etc. Theories, meanings, and objects of world 3 are real, but not real in this sense, and it only the ambiguity of Popper's criterion which allows confusion. As Armstrong points out, some problem sol goes on unconsciously. Certainly an account of this sort " theorizing" can be given in terms of brain states processes. So while a complete identification of brain st with problem solving may not make sense, no nonmat realm of being need be posited in order to account for things as problem solving. Mutatis mutandis the same can be said in regard to theories and other world 3 "objects.'
Popper does make direct criticism of Armstrong's identity
theory. It is noteworthy, however, that he does not present scientific evidence to refute Armstrong's position, but rather
gives a philosophical critique. The closest he comes to a
discussion of scientific ideas in relation to identity theory is
his claim that it is inconsistent with Darwinism and his
rejection of the validity of the "Gene-DNA" analogy for the
Popper criticizes all theories which posit consciousness but
do not accept dualistic interactionism as being inconsistent
with Darwinism because no such account of mind gives it
survival value. Unless the experiences of consciousness have
such value, there would be no reason for their continuance.
Armstrong could well reply, however, that this argument
presupposes that consciousness is nonmaterial. If it could be
shown that it is not physical and that its relation to the brain is
dualistic, then Popper would have a strong case. But until
then, this argument begs the question.
Popper also points out that "Gene=DNA" is not a true analogue for "Mental State=Brain State." As he mentions, all such analogies are appropriate only if it is supposed that mental states are physical states. But this supposition begs the nuestion. At most a correlation between brain states and states of consciousness can be shown not an identity.
The problem here is not simply one of technology. Popper expresses this point well when he writes in regard to the views
e does not suggest the kind of test which could possibly be regarded as a test of the identity thesis of mind and brain- as distinct from an interactionist thesis...15
What Popper fails to notice is that no such test is possible for either theory. Armstrong outlines the sort of evidence which might give overwhelming support for dualism, 16 but the sort of inexplicable unpredictability which he proposes as a possible criterion for the truth of dualism would be analogous to arguments which seek to establish God's existence by pointing to gaps in scientific explanations of the world. Each time a gap is filled God's realm of identifiable activity becomes that much smaller. No scientist as scientist ever says, "God is the scientific explanation for the occurrence of these events." Likewise, no scientist as scientist would ever say, "Now this event is due to the action of the nonmaterial mind." A "mind-of-the-gaps" theory is no better than a "God-of-the-gaps" theology. Until Popper and Armstrong are able to demonstrate the scientific testability of interactionist dualism or identity theory, one feels more inclined to believe that their starting place is erroneous and misleading, and that an appropriate solution lies outside the capabilities of legitimate science. The problem, it seems, is philosophic, not scientific.The Mind-Brain and God-Word Analogy
The last paragraph hints at the parallel between the mind-brain problem and the providence-science problem. just as any conceivable scientific evidence is compatible with either a physicalistic or a dualistic conceptual scheme, so any conceivable publicly observable events in nature (including historical events) are of themselves theoretically reconcilable to either a theistic or a materialistic ontology.
The impossibility of showing God's activity in the world by purely scientific investigation and argumentation becomes obvious when dealing with the Thornistic proofs for God's existence. if, for example, in the Ist mover or the First Cause argument, God's moving or causing is understood on the scientific level, it seems unnecessary, f or we can give perfectly satisfactory scientific explanations of any particular event. 17 On the other hand, if we consider God's activity to be of a different sort, virtually absorbing the first two ways into the third way, we find it impossible to argue scientifically for this new sort of causality. John Morreall. has clearly expressed this point. He refers to the following diagram in which a linear series of events, A, B, C, & D, are in direct causal sequence and simultaneously God has a distinct and direct causal effect on each event individually (from above), as well as on the entire sequence.
A B C D
... this scheme makes clear what the dilemma is. If we want to hold that C is caused by both God and some creature B, we will have to explain how the word "cause" is being applied to each. If God and the creature are held to be causing in the same sense, then ... God seems superfluous. B explains C perfectly well, and it is not even clear how God could cause in the way that B does. If we say that God's causing is a different kind of causality from A or B or C causing, . . . then the causal (the word being used here in its ordinary sense) regress in the natural order is irrelevant to any demonstration of God; for in the sense in which God is supposed to "cause," A, B, and C do not cause, and so could not have God as the first member in their series. God as a "cause" would not stop any regress of causes, since the word would not mean the same thing in the two cases.18
Morreall is concerned with meaning, not evidence' but
clearly if meaning is in jeopardy, so is any potential evidential
value. The Thomistic arguments might be salvable, but not by
scientific means, for if we talk of God causing things,
sustaining things, or upholding things, but mean this in a
metaphysical sense, we have ipso facto ruled out scientific evidence in behalf of this divine activity. If God's activity is
not on the same level or of the same kind as that of physical
entities, his activity cannot be demonstrated by the scientific
method, for that method is designed to handle only physical
explanations of physical events. This does not mean that it
makes no sense to speak of God's sustaining
activity; merely that it cannot be scientifically demonstrated,
and, importantly, for the same basic reason that the existence
of an immaterial mind cannot be demonstrated by recourse to
brain studies, namely, the lack of any scientific criteria by
which to test for divine activity. It may make more sense of
the world to posit an infinite God as creator, sustainer, and
ruler of the universe, just as it might make more sense to believe in the existence of an immaterial mind, but this
sense" will not, strictly speaking, be scientific sense.
Limitations of the Analogy
Certainly, the parallel has its limitations. But that is only to be expected when comparing a person and his brain with an infinite God and the universe. These limitations should be made clear at the outset. First, while the distinction between mind and brain can, at least conceivably, be left at the conceptual level, the distinction between God and the world must be existential. God is not merely the world as subjective experience, Spinoza's Natura Naturans, but is an infinite, self-subsistent being who exists separately from the world, even at that "time" when there was no world. Man's mind may only be conceptually distinguishable from his brain, but God is both conceptually and existentially distinguishable from the world.
Second, man is a psyebo-physical unity. His physical body is part of him. This is not the case with God and the world. The world is finite and created, whereas God is an infinite and eternal Spirit. Thus, while God cannot be compared univocally with the mind, the relationship between man's mind and his body can still have significant features which parallel the relationship of God with the world. The basis of this analogy is the nonmaterial nature of God's being and the nonmaterial nature of man's mind, on the one hand, and the material nature of the world and of man's brain on the other. But while the brain is a part of a person's body, the world is emphatically not God's body, although that suggestion has been made by some process theologians of the Twentieth Century.
Third, while man's bodily experiences can, by way of his
physical brain, affect his mental life, occurrences in the world
cannot affect the life of God. As a psycho-somatic unity,
events in man's psyche and his soma can affect one another;
as a self-subsistent Spirit, God's being is not open to influence
from his creation. He can decide to act in certain ways given
certain situations in the world, but he cannot be "moved" so
to act by an independent and prior act of any creature.
Strengths of the Analogy
Other dissimilarities may also exist, but let us now note the similarities. First, both God and man's mind exist in a nonmaterial, i.e., spiritual, "realm of being." Second, a nonphysical mind could be both imminent, (i.e., present with all those parts of the brain which are used to explain mental events on the physical level), and yet transcend the brain, (i.e., not be identical with the brain); God is, according to Scripture, imminent in the entire world, but not identical with any part or even the whole of it. He transcends the universe. Here the transcendence of the mind of man over his body would be one way, perhaps a key one, in which man uniquely mirrors his Creator.
Third, the mind of a person is involved in every voluntary act of the person, but every act can also be explained in terms of previous physical states. Likewise, an infinite God is present and active in every event which occurs in the universe, yet all such events have physical explanations. Man's body (including his brain) can be conceived and accounted for sufficiently as operating as it does without any input by an immaterial mind; likewise, a purely scientific account of all events in the world can be given. But importantly, just as a physicalistic description of human acts is adequate as a physical explanation but inadequate as a total explanation, so a scientific and physicalistic explanation of events in the world, while adequate scientifically, is not a total and complete explanation. In both cases, however, the insufficiency is not scientific, but philosophic. It is on the conceptual level that any sort of physical reductionism of mind to brain is demonstrably insufficient; likewise, it is in the same philosophical, conceptual area that materialistic accounts of the world fall short.
Perhaps the closest analogy to God's "causing" is our mind's willing. When I will to tie my shoes, an action occurs which would not have occurred had I not decided to tie them. From the impersonal, scientific perspective, however, a causal chain of events can be posited which need take no account of my mind's willing, although it will include statements about my brain states and neuronal activity, etc. Likewise, when God acts in his creation-and He does this continuously-on the physical level, a complete and selfsufficient chain of physical events, causes, etc. can be given; yet from the personal perspective, the perspective of meaning, such an account is inadequate, just as it is for my shoelace tying. I know by personal experience that talk of persons willing is not nonsense even though I have no scientific need of such language; likewise, my talk of God's willing and acting is similarly meaningful.The Reality of Minds and God
1Karl Popper and John C. Eccles, The Self and Its Brain, (Springer-Verlag: New York, 1977).
3D.M. Armstrong, A Materialist Theory of Mind, (Routledge and Kegan; London, 1968).
4Popper, pp. 6-7.
5ibid., p. 7.
6bid., p. 9.
ibid., p. 10.
9ibid., p. 96.
10Armstrong, p. 358.
11Popper, p. 23,
12Armstrong, p. 361.
13Popper, p. 45.
14 ibid., pp. 48-49.
15Ibid., p. 96.
16Armstrong, p. 360.
17See John S. Morreall, Analogy and Talking About God: A critique of the Thomistic Approach, (University Press of America: Washington D. C., 1978), pp. 55-56 for an excellent illustration.
18ibid., p. 60.