SCIENCE, CELLS AND SOULS

Although we are all human, human nature is full of mysteries. “What is life?” “ Does our soul survive death?” “ Do we have free will?” It used to be enough to sit and think about them. But today such questions seem increasingly a matter for science. Can we make life? Can education improve intelligence? What would it be like to clone a human? Does the electrical activity of the brain mean that free will is an illusion? Will we soon share the world with intelligent machines? If one has not studied science it is difficult to assess modern research: if one is unfamiliar with philosophy it is difficult to criticize one’s intuitions. This is a good time to study human nature. Some claim that we can tell from patterns of brain activity when people are telling the truth, when they make voluntary choices, and even when their religious belief is active. What are we to make of such claims, which seem to be about mental or spiritual activities, but are measured by physical events? How does the new science relate to the classical ideas about our nature that have come down to us as “the wisdom of the ancients”, the subject matter of philosophy? The underlying theme of this book is that mere scientific knowledge does not by itself deepen our understanding of human nature. We must relate it to ideas that were common before the rise of science. There are traditional words that seem intrinsic to human nature. I call them Fundamental Words and they include “self”, “body”, “mind”, “will”, “soul”, and “life”. Are such words the names of parts of a person, non-physical, immaterial, or “spiritual”? Many books today discuss modern neuroscience and biology as if their success means there is ever less reason to retain older ways of talking. That risks impoverishing our understanding. In this book we will try to connect the old and new ways of thinking. * * * If science is straightforward in what it has to say, what about philosophy? What about the souls of living things? Think again of Saltarella. She was “nothing but” the molecules of which her body was made, but an account of why she jumped is unable to capture the reality of the jump with a “nothing but physics” account. While an animal is alive it is highly organized. Its body is composed of identifiable organs and each organ is composed of identifiable kinds of cells performing their functions to maintain the function of the organ. Only at death do all these levels of organisation disappear, and the components and energy of the organism become increasingly randomly spread about the environment. The body rots and its chemicals diffuse into the environment: “ashes to ashes, dust to dust”. But during life, the organism retains its integrity and functions as an individual . It is, as Aristotle said, ensouled. * * * But the important principle is that all the activity of the nervous system, all the activity of the brain, consists of electrochemical interactions among cells. Somehow our entire mental life is carried by this kind of activity, and we understand the physical chemistry in great detail. It seems that we can account for the properties (anatomical, chemical, physiological and even behavioural,) of people on the basis of physics and chemistry: we can tell a satisfactory Scientific Story about living humans. Whatever the word mental means, it does not require us to believe that there are mysterious events, the life of a “ghost in the machine”, to account for consciousness, acts of will, and so on. Apparently when certain physicochemical events occur in certain cells we experience mental events and feelings. Of course we have conscious experiences in addition to showing behaviour. Of course we have the experience of choosing without feeling compulsion. But never forget that whatever your idea of mental life may be, it can be snuffed out by being hit on the head with a brick. A Scientific Story must be the basis of our understanding of human nature. * * * Can we make a machine think? Does a camera “see” the smile on a face, or merely respond to it. Is a robot companion merely a camera with legs? Or could it be a friend ? The conclusion from Turing's analysis seems to be that any function or operation that can be completely described in terms of symbolic logic can be performed by a computer. After all, mental arithmetic is not arithmetic done in a ghostly schoolroom in the skull: it is just ordinary overt arithmetic done quietly. To see this, do an arithmetic calculation with a pencil on paper. Now do a similar calculation without using the pencil, but speaking the words aloud as you calculate. Now do it again, but moving your mouth and tongue without speaking aloud. Finally do it with your mouth shut and your tongue quite still, “in your head”. You have certainly changed from doing overt arithmetic to doing mental arithmetic, but you have not moved deeper and deeper into your mind and changed from using a Pencil as a Machine to a Ghost in the Machine! * * * These days hardly a week passes without a report in the media to the effect that by using fMRI or some other method of recording from the intact brain we have discovered the region where thoughts occur, or religious sentiment is located, or emotions emerge. The real problem, The Hard Problem, is untouched by any of this research. Why does this particular collection of physical stuff not just respond physically? Why is it aware of responding? That is the Hard Problem, the fundamental question about the mind, and knowing about what part of the brain does what gives no help towards an answer. Why are we conscious when seaweed, for example, is not? * * * Descartes's dualism was meant to show that consciousness was not tied to the states of the physical body. But anyone who has had deep anaesthesia knows that while we may not have direct proof that thinking can occur without a body, we certainly have evidence that the living body can occur without consciousness! What, after all is the typical experience of deep anaesthesia? You are not aware that you exist, and you are not aware that you are alive. The surgical team knows better than you do whether you exist. All this is hardly what you would expect from a Cartesian ego. If your conscious mind, your ego, is meant to be able to exist when your body dies, why does it become completely inaccessible to you when your body is still alive, just because a bit of the brain has been chemically altered? And why does dementia slowly destroy reason? As Aristotle pointed out, “. . . in old age the activity of mind or intellectual apprehension declines only through the decay of some other inward part.” A Cartesian ego should not experience dementia. * * * If I have been hypnotised you may say, “Actually, the reason that you gave the beggar the money was because while you were hypnotised you were given a suggestion that you would do so but you would not remember that you had been given the post-hypnotic suggestion.” And then I say, (and this is the critical move to preserve my responsibility,) “I am quite prepared to admit that I was forced to give him the money by the hypnotist. But that is an action that I would like to have done, even if I had not been forced to do it. It is an action that had I been free to do so, I would have chosen to do. The fact that I was forced to do it may be true, but I approve of it. I claim it as my action.” That is enough to take responsibility. There may be no such thing as a free will, indeed no such thing as a will at all, but there can be responsibility none the less. * * *