I once had a blind student who told me that her blindness was functional. When I asked her what this meant, she told me that she had minimal vision but that it had no function in her life, since it did not enable her to discern objects. I asked her what her visual experience was like and she told me that it consisted of the experience of colour. It seems evident in this case that we can distinguish sharply between conscious experience and its function in behaviour. For the girl's conscious experience did not in fact have any such function. We can arrive at the same distinction in another way. In a cat's ears there are very fine hairs. If you put drops of water on the hairs, the cat will jerk its head, rejecting the drops. If you remove the cat's brain, it will still perform that act. In other words it will perform the same act even though devoid of consciousness. T.H. Huxley in a once celebrated lecture described a similar case. If a frog is held in the palm of the hand and the hand is turned slowly, the frog will not fall off but will perform a delicate balancing act, reappearing on the uppermost part of the hand. Huxley reported that a frog had performed this act, even when the greater part of its brain had been removed. Moreover when thrown into a pond it had swum away exactly like any other frog. Thus we have not only consciousness without functional behaviour but also functional behaviour without consciousness. The two seem evidently different. It was cases such as these which persuaded philosophers of a physicalist turn that they should abandon the behaviourism that flourished in the first half of the last century. Instead they attempted to identify consciousness with the brain.

I have mentioned the above cases because they are relevant to the papers by William Charlton and Nicholas Lash, recently published in this journal.Footnote ¹ I am not suggesting that either Charlton or Lash identified consciousness with the brain. But they are at one with the physicalists in rejecting any form of dualism. By dualism I mean the view that mind and body are distinct substances or natures. Let us return for a moment to our first example. I did not know what the girl's visual experience was like until she told me, but I could observe how she behaved. Again I could observe the frog's delicate balancing act but I could not tell from what I observed whether it was conscious. It seems natural, therefore, to distinguish in human beings and other creatures between different substances, or, if you dislike the term substance, between different natures - the material and the immaterial. That is dualism.

As I have said, both Charlton and Lash object to this view, attributing its influence to the work of Descartes. Lash, indeed, seems to take the view not simply as false but as pernicious. He suggests, for example, that “Cartesian Dualism” has the whole of our culture in its shackles. In order to liberate us from these shackles he appeals, like Charlton, to the works of Aristotle. On Aristotle's view, the mind or soul is simply the form of the body. Both Charlton and Lash interpret this to mean that when we refer to mind we are not referring to something distinct from the body. Rather we are referring to certain special capacities of the whole body itself. Lash endorses Anthony Kenny's definition of the mind as “the capacity for behaviour of the complicated and symbolic kinds which constitute the linguistic, social, moral, scientific, cultural and other characteristic activities of human beings in society”.Footnote ² Charlton illustrates Aristotle's view with a metaphor. A shelter is not an entity over and above the bricks and mortar that constitute it. In referring to it as a shelter we merely indicate the function served by those bricks and that mortar. Similarly mind is not an entity over and above the material parts which constitute a body. It is a way of treating the whole body in its functions or capacities. Even at this stage, we may be inclined to point out that a shelter is not conscious. By contrast, human beings are not simply conscious of the functions they serve. The functions they serve are essentially those of conscious beings. We cannot define consciousness by means of the functions. We have to define the functions by means of consciousness.

But let us return to Kenny's definition of the mind as the capacity for certain kinds of behaviour. It is important to note that these kinds of behaviour are not specified as manifestations of mind. They are specified as identical with it. Charlton has the same view. He tells us that “the only intelligent capacities we have are the specific arts and sciences and the good and bad dispositions we acquire as we grow up.”Footnote ³ Again the suggestion is not that intelligence manifests itself in these activities, which is platitudinous, but that it is identical with them.

Now these are puzzling views. Suppose I walk along pondering a problem. At the turn of a corner I arrive at the solution. When I arrive home I write it down. My writing it down may certainly be taken as an overt act, an instance of bodily behaviour. But I did not arrive at the solution when I wrote it down. I arrived at it earlier when I was turning a corner. Nor can it be said that what occurred at the corner was a disposition to write it down later. Rather, any such disposition is to be explained by my having arrived at the solution then. In common speech it would be absurd to describe this occurrence as an act of my body taken as a whole. It would be described rather as occurring in my mind, as an act not of my body but of my intellect.

Consider another type of mental event. I may feel pain, lasting for a certain time and varying in intensity. This may certainly be linked to bodily phenomena. For example I may writhe and groan. But if a doctor asks me to describe how my pain varies in intensity, he is not asking me to describe my behaviour. He is not referring at all to my behaviour when he refers to my pain. The phenomena are distinct. They count as two not as one. The point is the more evident in that one can be in pain without exhibiting pain behaviour and exhibit pain behaviour without being in pain. Wittgensteinians argue that there is a conceptual link between pain and pain behaviour in that the behaviour belongs to the sense of the concept. It may well belong to the sense of the concept but it does not belong to the reference. As I have said, when I refer to a person's pain I do not refer at all to his behaviour.

We may note also that pain is somewhat exceptional among mental phenomena in having a standard link with patterns of behaviour. No such links are discernible in the case of any number of other mental phenomena. From my behaviour you cannot tell what I am dreaming, imagining, pondering, recollecting, etc. Consider how many thoughts flit in and out of your mind as you walk the length of a street. Throughout this time your mind is continuously at work. But its workings cannot be discerned from observing how you walk the length of the street.

We have seen that both Charlton and Lash rely on Aristotle's distinction between form and matter. But in my view they misrepresent that distinction. What Aristotle meant by form was not some aspect of a being wholly constructed of material parts. Matter, on his view, is actualized by form, so that the latter cannot be an aspect of the former. His distinction between form and matter is in fact roughly equivalent to the distinction between the immaterial and the material. It is true that he treated sense experience as intrinsically involved with matter. But that is not true of the intellect. For Aristotle, the intellect is purely immaterial and partakes of the divine. That is certainly how Aquinas read him. Thus Aquinas sees no inconsistency in asserting that between death and the Last Judgement, the soul exists independently of the body. That seems as definite a dualism as any one might find in Descartes.

We must turn at this point to “Cartesian Dualism” itself. How exactly are we to understand this doctrine? According to Charlton and Lash, body and soul, for Descartes, are not simply distinct but actually separate. Thus, for Descartes, the soul is in the body as a diver is in his diving suit or a sailor in his ship. It is not entirely clear to me why they hold this view. Perhaps this is an illusion but they seem to hold that unity as such is incompatible with distinction or composition. Charlton, for example, states that “a human being is a single thing, not a composite of soul and body but a unity”.Footnote ⁴ This surely suggests that unity and composition are mutually exclusive. But that is obviously false. Descartes distinguished carefully between unity of composition and unity of nature. A single thing may be composed of different natures. An obvious example is the body. It is a single organism composed of different organs. Each organ differs in nature and function from the others but taken together they form a single organism. A person, therefore, may be a unity whether or not he is composed of soul and body.

In any case there can be no question about whether Descartes held that the soul is in the body as a sailor in his ship. For he explicitly rejected that view, not in a fit of aberration, but on the basis of reasoned argument.

“Nature also teaches me, by these sensations of pain, hunger, thirst, and so on, that I am not merely present in my body as a sailor is present in his ship, but that I am very closely joined and, as it were, intermingled with it, so that I and my body form a unit. If this were not so, I, who am nothing but a thinking thing, would not feel pain when the body was hurt, but would perceive the damage purely by the intellect, just as a sailor perceives by sight if anything in his ship is broken. Similarly, when the body needed food and drink, I should have an explicit understanding of the fact, instead of having a confused sensation of hunger and thirst. For these sensations of hunger, thirst, pain and so on are nothing but confused modes of thinking which arise from the union and, as it were, intermingling of the mind with the body.”Footnote ⁵

There is one feature of this passage which, although it is not to our immediate purpose, deserves a comment, for it is interesting in itself. Descartes there refers to hunger, thirst, pain and so on as confused modes of thought. He has often been criticized for this view. Yet what he means seems perfectly clear. A sensation of pain, for example, is not a physical occurrence, for it takes a reference and informs me that there is something wrong with a part of my body. In this it is akin to thought. On the other hand, it does not give me a clear understanding of what exactly is wrong. To obtain that, I do have to inspect my body, as a sailor inspects his boat.

But what is especially evident in the above passage is that Descartes was not a “Cartesian Dualist”. It is true that there are difficulties in the form that his dualism took. But they did not arise from what he said about the mind. They arose from what he said about the body. They arose, indeed, not from his philosophy but from his physics. In his physics Descartes's views were akin to those of Galileo. As is well known, Galileo distinguished sharply between mind and matter, attributing all qualitative differences to the mind. In this way he was able to treat matter in purely quantitative terms. Descartes's treatment of matter is also purely quantitative. But here arises an obvious problem. The distinction between mind and matter has been turned into a dichotomy. In other words, the two are being defined not simply in different but in mutually exclusive terms. In that case, however, it is impossible to see how they can compose a unity. Aristotle and Aquinas did not have this problem. For them, mind and matter were different but not discontinuous. In perception, for example, the mind takes on the form of the perceived object. Thus mind and object have a common form. It is important to emphasize, however, that Descartes's difficulty did not arise from his dualism as such. It arose from attempting to combine dualism with a purely quantitative theory of matter.

But let us turn from the history of philosophy to the Christian faith. Charlton and Lash believe that Christians can be muddled in their faith through the influence of dualism. The trouble is that this dualism is central to the faith itself. Here is an extract from the Athanasian creed.

Here the unity of two natures in Christ is explained precisely by an analogy with the unity of two natures in a person. Moreover it is insisted that the two natures are really distinct and not to be confounded.

The analogy is pointless unless we treat a person as composed of two natures, body and soul.

Moreover this dualism is not confined to theological doctrine. It is part of ordinary worship. Here is a quotation from the Book of Common Prayer. It is the Collect for the Second Sunday in Lent.

How can we make sense of that prayer without supposing a real difference between body and soul and between the evils attendant on each?

The relevance of this dualism is especially evident when we turn to the Christian faith in life after death. If our souls are dependent on our body how can we survive its destruction? Charlton deals with this problem in some detail. He quotes from a beautiful prayer which concludes by asking God to “grant us, through the mystery of this water and wine, some part of the divinity of Him who came in His goodness to share our humanity.” This process of divinisation, as Charlton calls it, involves, through sacrament and worship, our coming gradually to partake of the nature of God. Moreover since there are no material constituents in God, the more God becomes incarnate in us, the less we require material constituents ourselves.

It is in this way that Charlton explains the possibility of life after death. To do so, however, as is surely evident, he has himself resorted to dualism. The more God becomes incarnate in us, the more we partake of the immaterial. But if we partake of the immaterial then obviously we are two natured, both material and immaterial.

Now one does not want to underestimate the importance of sacrament and worship nor indeed the importance of what Charlton calls divinisation. In certain respects, what he says is true and important. But it has always been part of the Christian understanding that God entered into a special relation with the human species from the beginning. Indeed the very prayer which Charlton quotes has as its opening words: “God, you created human nature in marvellous dignity.” Man, we have been taught, was created in the image of God. The Athanasian creed implies that any person is dual natured, composed of body and soul. In short any person is a soul qua immaterial and a body qua material. But since we partake of the immaterial we may hope, through the grace of God, to rise above the material and inherit everlasting life. That seems to be the Christian view. It was also Descartes's.