Mind-body interactionism

in the light of the parapsychological evidence

As a realist, as opposed to an empiricist, I take the view that, thanks to the progress of science, we already know a vast amount about matter and the behaviour of inanimate objects, we know something also about living organisms which exhibit mind- like behaviour and we have as well an insider's understanding of the behaviour and experience of our fellow beings but, when it comes to the fundamental nature of mind and its essential powers, we know scarcely anything at all. Mind as such remains the densest of mysteries.

There are those who argue that, in the aftermath of the latest revolutions in physics, matter has become so ethereal, so far removed from what we took it to be during the era of classical physics, that the old mind/matter dichotomy has ceased to have any relevance. Thus, we find Dunstan McKee, writing recently in this journal,1 asking: "does it make sense to maintain the physical/non-physical distinction in science? What cutting edge does it have?" and suggesting that we drop forthwith all further talk about dualism and materialism and start discussing instead "the question we are all interested in, namely 'what is reality like?'" Certainly, I would agree with him that it should be the aim of philosophy no less than of physics to help us understand what reality is like rather than chop it up into arbitrary categories. But I would not agree that modern physics has so blurred the distinction between the mental and the physical that the way is open for a monistic conception of reality. Indeed, the only real grounds that I can find for such a contention rest on what the quantum physicists call the measurement problem. They take it now to be axiomatic that the state of a given physical system will differ according to whether a certain critical observation is made or not made. Now this certainly raises problems about the meaning of objectivity in science but it would seem to be equally compatible with an interactionist as with a monistic metaphysics. But, for the rest, although quantum theory confronts us with a highly paradoxical universe when we try to explore the fine grain of the material universe, there is nothing that I know of in the new physics which would suggest to me that matter possesses any mind-like characteristics.

What is it, then, that makes us want to designate something as mind-like and something else as purely physical? To Descartes belongs the eternal credit of having first insisted upon a clear categorical distinction between the mental and the physical. But this does not mean that we are forever bound by the particular criteria he used to make this distinction. All the world knows that Descartes took extension to be the defining criterion of matter and thought to be the defining criterion of mind. Res extensa was contrasted with res cogitans. But this is clearly open to all sorts of objections, for example percepts and mental images are plainly extended in the geometrical sense even though they do not occupy a region of physical space. Similarly, to a modern physicist the dynamic properties of matter might seem more important than its purely spatial properties. As for mind, the danger of identifying it with its conscious manifestations, as Descartes implied in using the generic term "thought", can be seen in the history of empiricist philosophy. For mind came to be regarded as something so intermittent and fragmentary that, eventually, it was natural to treat it as no more than an epiphenomenon of brain states. If we are to form a conception of mind that does justice to our common sense intuitions and can serve as the basis for a theory of the self, we shall have to treat it as the enduring seat of our mental capacities and dispositions, not just as a series or collection of specific mental events.

What, then, can we reasonably say at the present time about the respective characteristics of that which pertains to the domain of the physical and that which pertains to the domain of mind? Let us begin with matter. It is still as true today as it ever was that a physical object or entity exists in space, that it can change position in space and that it has the power to attract or repel other physical objects or entities. And that, moreover, is just about all that needs to be said in this context. All the sophistications of physical theory are concerned with the structural complexities of matter and of material systems and with the precise mathematical laws which govern their behaviour. It is harder to know exactly what to say about mind but there are, at any rate, three features of mental events and processes which have no counterpart among physical events and processes. The first of these is the presence of consciousness in the most primitive sense of sheer sentience or feeling, the sense in which we suppose it to be present in all animal life but probably in no plant life and almost certainly in no inanimate objects or mechanical artefacts.


The second is the referential aspect of the cognitive processes in man and the higher animals. I mean by this that our thoughts, percepts, memories and so forth represent, symbolise or otherwise refer to something other than themselves. This is a very vital point and we may recall that Brentano and the 19th Century "act psychologists" took this as indeed the cardinal feature of mind. A physical process, per contra, however complex, is just a physical process. It may interact causally with other ongoing physical processes but in no sense can it refer to anything other than itself unless, that is, we ourselves choose to treat it as a symbol but, qua symbol, it is no longer a physical process. I have deliberately laboured this point because of its implications for the mind-brain identity theory, the most popular current version of materialism. For it makes it extremely dubious whether such a theory is logically tenable. For to claim that two entities are identical implies that whatever can be said about the one entity can equally be said about the other entity. However, while I can say what my thoughts are about, it seems to make no sense at all to say about the concomitant brain processes that they are about anything, they just are. But in that case there appears to be an insuperable difficulty about identifying my thoughts or my thinking with any set of brain states or with the electrical impulses in the neural circuits of my brain*.

* I owe this argument to my colleague Dr G. C. Madell of the Department of Philosophy at Edinburgh.


The third distinguishing attribute of mind to which I want next to draw attention is the familiar intentional or purposive aspect of behaviour which transforms what otherwise would be a mere sequence of movements into a meaningful action. A machine can go through any sequence of movements which the ingenuity of its inventory will allow but no purely physical system can act in the sense in which this implies an intention. I realise that this point would be vigorously challenged by those who have embraced a cybernetic view of human behaviour. I am aware, too, that the study of our skilled and adaptive behaviour has been powerfully influenced in recent times by the analogy with self-regulating mechanisms, just as modern cognitive theory has been strongly influenced by the work in artificial intelligence. I would maintain, nevertheless, that to equate the cognitive processes of human beings or animals with the information processing of computers is to confuse that which is simulated with its simulation. Thus, it is one thing to design a robot capable of performing some perceptual type task such as selecting an object of a particular shape from an assortment of other objects. But it is quite another thing to claim that the robot perceives the object because perceiving implies, among other things, having certain conscious percepts and if anyone were to suggest that the robot was conscious we would suspect him of prevaricating in his use of the word consciousness. Similarly, while it is entirely natural to speak of a computer as solving problems, playing games, making decisions or even engaging in conversations we should not allow such talk to obscure the fact that the apparent intentionality of such performances is not anything intrinsic but derives from the fact that we invest them with meaning. It is not merely that the machine is not conscious of the ends which it subserves for it often happens that we ourselves may act purposefully without necessarily being conscious of the fact, indeed all our skills have a certain tacit dimension, the point is rather that the machine can never become aware of what it is doing and why. Hence, so long as we are dealing with automata, no matter how cunningly contrived to mimic mindful behaviour, we are still firmly within the domain of the physical.


It seems, then, that there is no great difficulty in distinguishing clearly between the mental and the physical but, having made the distinction, there is still one crucial problem to which critics of dualism have always drawn attention and which, indeed, worried Descartes himself and his followers. For the question arises: if mind and matter have no properties in common, how can they interact? Thus we find McKee putting forward as a "conclusive theoretical argument" against a dualism of the categorical Cartesian kind that, either we are driven to deny that the two disparate entities do interact, in which case the mind-body relationship becomes wholly mysterious, or "it still needs to be explained how entities of different kinds can interact, and I do not see how this can be done."3 This frequently voiced objection was thought to be so unanswerable that all kinds of preposterous solutions - occasionalism, parallelism, idealism etc.-were invented by the philosophers expressly to account for the ostensible mind-body interactions.

Actually, all this philosophical ingenuity was wasted for, when we examine this argument, we find that it rests on nothing more than the assumption that there is only one kind of causation, namely the mechanical causation exemplified by the interactions between material bodies. But, as Ducasse and others have shown,4 a careful analysis of the meanings of cause and effect provides no grounds for supporting that, as McKee puts it "the entities must be of one kind." Stated in its simplest terms, we can say that if we are satisfied that an event E would not have occurred under conditions C but for another event X then, ipso facto, we are entitled to call X the cause of E whatever might be the nature of X or E, whether one be mental and the other physical or whatever. In the last resort, despite all that philosophers have said to the contrary, it does not even matter whether X occurs after E rather than before E although, obviously, such backward causation would be highly anomalous.

But, although interactionism cannot be faulted on logical grounds, I would be the last to deny that it does create enormous problems for science and more especially for the unified scientific world view. The point is that physics has provided us with a conceptual framework which makes material interactions intelligible. We have a model of how causal trains are propagated through space in an orderly fashion, of how forces act on bodies and so on. No such coherent model exists in the case of what Ducasse calls psychophysical or physico-psychical causation and, indeed, the question whether any such mind-matter interactions do in fact occur remains a legitimate empirical question. It is not surprising that, when physiology came into its own in the late 19th Century, the orthodox scientific view of the mind-body relationship was that of epiphenomenalism which ruled out the possibility that mind could in any way influence behaviour, allowing only, what seemed too obvious to deny, that events in the brain could affect consciousness. Latterly epiphenomenalism has fallen from favour being supplanted by the more parsimonious - though, as we have seen, logically much more questionable-identity theory. The identity theorist makes much of the fact that by literally identifying mental processes with brain processes he has restored to mind its active function since now it participates in whatever causal functions we assign to the brain events. Yet the implications of identity theory are no different from those of traditional epiphenomenalism, namely that a complete theory of behaviour is in principle possible using exclusively neurophysiological terms. In both cases the conscious concomitants are irrelevant, the course of nature would be the same even if they did not exist.

Consider, for example, some simple basic action such as raising one's arm. On the materialist view, the fact that at some instant I decide to raise my arm so that I can reach for something on a shelf, let us say, has no bearing on the question of why my arm rises. The mental event or volition as it would traditionally be called is either a by-product of the particular brain state that initiates the movement of my arm (epiphenomenalism) or it is an integral part of it (identity theory). But, in either case, its explanatory value is nil, it remains a contingent fact that there should be any mental event at all, the behaviour we actually exhibit would be exactly the same, so long as our physiology remained the same, even if we were just automata. Our mental life is on this view a reflection of our behaviour but has no more influence on it than the colour we choose to paint a machine has on its functioning.

Now it has always seemed to me that to deny the interactionist thesis is to make a stupendous sacrifice of our most deep-seated common sense beliefs on the altar of science. Of course, the adoption of the objective scientific standpoint often entails a sacrifice of our untutored intuitions. But, before we agree to a sacrifice of this magnitude which, in effect, destroys the very basis of the traditional view of what it means to be human and to exercise human autonomy, we ought to make very sure that the science for whose sake we are being asked to perform this act of self-abregation is indeed a valid one. And it is on this question that I want to make the principal point of this paper, namely that the case for the materialist interpretation of behaviour - and it is a strong one - rests upon what I shall have to call "normal" science (not in the Kuhnian sense but as opposed to "paranormal" science). In the remainder of the paper, therefore, I shall consider what would be the implications of accepting as valid at least the more reputable portion of the parapsychological evidence.

It will not be my claim that this evidence refutes materialism, that would be putting it much too dogmatically, my contention is rather that it supports interactionism which, let us never forget, already enjoys the sanction of common sense. It is true that many who are currently active in parapsychological research-and this applies especially to those who have come to it from the physical sciences-are convinced that the paranormal can eventually be conquered for physics, given only certain extensions and modifications to our existing physical theories. They would deny that parapsychology-or "paraphysics" as some would prefer to call it- represents any sort of a threat to materialism, all that is at stake is our current conceptions of the physical world. And given the fact that, in the present state of the art, parapsychology can be defined only in negative terms, as concerned with that which cannot be explained using currently acceptable scientific principles, they are perfectly free to adopt this stance. The danger of persisting in it, however, is that it threatens to make the concept of the physical logically vacuous. In the end, to be "physical" may mean nothing more than to be "real." The difficulty is that we are dealing here with ill-defined concepts and shifting rules. How far can physics be stretched and remain physics? And, if we cannot lay down in advance what are the limits within which a particular world view remains tenable, then there can be no question of proof or refutation.

The pertinent question is what kind of a metaphysic is more consonant with the parapsychological evidence and on this point I would argue that interactionism has a decisive advantage. Recently John Randall suggested that we "redefine parapsychology as the science of mind-matter interaction"5 and, although in view of our continued ignorance about "psi phenomena" such a suggestion may strike one as premature, it does, I believe, represent by far the most promising positive characterisation of the field that we can yet offer. Indeed, historically, this has always been the dominant view of the field. Parapsychology, we must remember, grew out of the conflict between science and religion which came to a head in Victorian England and was an attempt to reconcile scientific canons of evidence with the transcendental view of human personality that was the legacy of religion. For the early researchers the supreme challenge was to obtain strict empirical evidence for the reality of survival. And, had their patient efforts been crowned with success, this would have vindicated dualism in the most direct manner conceivable since survival would plainly be impossible if the mind were either identical with, or wholly dependent upon, the brain which is destroyed at death. In the event they failed, the evidence they adduced was never sufficiently specific or so unequivocal that all alternative interpretations could be ruled. out. And perhaps, in the very nature of the case, it could not have been otherwise.

When, later, parapsychologists turned instead to establishing the existence of the more mundane phenomena of ESP and PK, it was still with the aim of showing that the mind possesses powers which defy an explanation in physical terms. Even allowing for the possibility that there may be senses as yet unknown to the physiologist or novel forms of energy as yet unknown to the physicist, it was still argued that ESP and PK could not be accommodated within any physicalist framework. Thus, emphasis was laid on the fact that ESP, in particular, appeared to be independent of the space-time parameters which figure in any system of physical communication and that it appeared to be equally unaffected by any material barriers that might be interposed between the subject and his target. Rhine, himself, repeatedly claimed to have proved once for all the "non-physicality" of psi, appealing especially to the time-transcendence as demonstrated in his experiments on precognition. We can now see that this was to take a too naive view of physics. Rhine was right in thinking that psi could not be brought within the purview of the classical physics on which he had been nurtured; those who were at home with the paradoxes of the new physics were by no means so convinced that psi was self-evidently non-physical in nature. Nevertheless, the crucial fact which emerged from the original work of the experimental parapsychologists was the total absence of any systematic relationships between these psi effects and any set of known physical variables. Such weak relationships as could be derived from the data indicated the relevance rather of the psycho- logical variables-e.g. the attitude of the subject, the personality of the experimenter etc.-certainly there was no clue as to any possible physical, or even quasi-physical, mechanism which could mediate the transfer of information between subject and target.

In the face of this still fruitless search for a physical mechanism, some contemporary theorists have been suggesting that we would do best to abandon altogether the causal mode in trying to understand such phenomena and settle instead for what Jung called a "synchronicity principle." The occurrence of ESP or of PK would constitute a "meaningful coincidence," a pair of "confluent events," a case of "anomalous knowledge" or "anomalous action"; whatever expression we use the implication is that no causal transaction of any kind, physical or non-physical, normal or paranormal, is involved.6 This strikes me as a desperate expedient which, even if logically defensible, is unnecessary and, if it were adopted, would soon stultify all further inquiry into the phenomena. What I think the situation does demand is a fresh look at the peculiar kind of causation that is involved in mind-matter interactions.

Mechanical causation, as we remarked earlier, consists essentially in bodies attracting or repelling each other in accordance with fixed laws of a mathematically describable nature. Nothing in the physical world, we can safely say, happens in order to fulfil some particular objective. Nature frequently reveals what may properly be described as "teleonomic structures" where it looks as if they were brought about in fulfilment of some preconceived design but invariably a closer analysis will show that they came into being as a result of some interplay of chance factors and mechanical causes such as holds for the rest of the inanimate universe. Now I want to suggest that the most important single aspect of psychic or psi phenomena in this connection is that they are irreducibly teleological in character. We may hunt in all directions for the pushes and pulls, however subtle, which could account for the effects we observe but we find none. In the end, all that we find ourselves able to say is that a certain effect was achieved for no other reason than that the subject willed it to be so, that, in the ESP test, he willed the concealed target to become manifest or that, in the PK test, he willed the particular physical outcome. In a typical PK test, moreover, the subject knows nothing at all about the particulars of the target system which he is trying to influence which, nowadays, may be an electronic random number generator triggered by a radioactive source or by the fluctuating noise-level in the electrical input. But, even if, per impossiblie, the subject could be given complete knowledge of the set-up involved there is no conceivable way in which he could utilise this knowledge to achieve his ends. We speak glibly of PK as a "mind over matter" phenomenon but what this expression seems to mean, if it means anything, is that we are witnessing a case of matter behaving teleologically under the constraints imposed by mind.

Given this conception of the psi process we can now look again with enhanced understanding at the commonplace mind-body transactions of everyday existence. In all but one respect the PK situation resembles point for point the basic action we discussed where we deliberately move a limb. In both cases we know nothing, or at any rate nothing to the point, about the physical processes by means of which the task is accomplished. Our contribution begins and ends when an intention is somehow put into effect. The one difference is that, in the normal situation, it always remains theoretically possible that this intention is itself the effect rather than the cause of the physical events with which it is associated and it is this possibility that keeps the materialist in business. In the PK situation, on the other hand, there is, ex hypothesi, no such physical link connecting the subject with the target system which could give the materialist a leverage. It appears, then, that we have only two options: either we must explain both situations, the normal and the paranormal one, on quite different principles or we must regard them both as instances of the action of mind on matter and of teleological causation.

The parallel between ESP and normal cognition is rather more problematical. Nevertheless, it is tempting to think of perception as a case of the mind reading off the information content of the brain on the analogy of the mind reading off the information of the target-object in an act of clairvoyance. This makes better sense, perhaps, than to think of the percept as an automatic by-product of cortical activity. Similarly, it is tempting to think of the conscious recollection of some event as a case of directly retrocognizing a past experience than as the product of an elaborate process of retrieving stored memory traces as the orthodox account would have it. But that is all surmise. The essential point I want to bring out here is that, on the view I am advocating, it is just a contingent fact, explicable no doubt in terms of our evolutionary past, that most of our transactions with the world are effectuated through the brain. Paranormal action and paranormal cognition occur when, for some obscure reason, we are able to by-pass this dependence on the brain and allow the mind to interact directly with the outside world.


One final comment is necessary if misunderstandings are to be avoided. I have argued that we cannot afford to neglect the parapsychological evidence if we hope to arrive at a correct understanding of the scope and nature of mind. At the same time it must be admitted that the picture of the mind which parapsychology presents is very different from that which we associate with traditional Cartesian dualism. In the first place, far more weight must be given to the unconscious activities of mind than is allowed for in conventional psychology even when tempered with a little depth psychology. The fact is that even the most gifted psychic has at best only a very hazy conscious control over his phenomena. Secondly, psi phenomena are very hard to reconcile with the traditional individualistic conception of mind, often, for example, it is very problematical where one should locate the psi source and whether more than one individual is involved. The phenomenon of a "group PK" is one that parapsychologists now have to reckon with. Thirdly, although there are many different ways of conceptualising what takes place in a so-called telepathic interaction, the possibility of a coalescence of minds is one that cannot be definitely ruled out especially when an awareness of another's pain or emotion is reported. And lastly, and to me it seems, most tellingly, the kind of achievement represented by successful exercise of the psi faculty so far exceeds the mental capacities of the individual subject that it is hard to avoid invoking some kind of cosmic intelligence or information pool which the individual can somehow tap and for which he can serve as a conduit. For all such reasons, the view of mind to which parapsychology may lead us may differ radically from that with which we started. But even if we should end up by having to acknowledge that an individual is only relatively autonomous and that the only abiding reality is some sort of universal mind or spirit which works through the individual minds, this would in no sense dispose of the case for mind-matter interactionism and that, after all, is what this paper has been concerned to establish.