From: Geoffrey Klempner
Subject: Speculations about the soul, brain and consciousness
Date: 24 December 2002 12:34
Thank you for your e-mail of 15 December, with your first essay for the Philosophy of Mind program, entitled, 'The First Speculations About Soul, Brain and Consciousness.'
Your 'essay' is in fact the very condensed material for several essays. I will deal with each of your headings in turn:
Brain, materialism and science
I saw a TV program based on Dr Sacks' remarkable book. How indeed can we make sense of the way these patients 'think'?
Arguably, you could have gone much further in drawing conclusions from experimental work. For example, if we consider the experiment where the corpus collosum separating the two halves of the brain is severed (as a last remedy for severely epileptic patients) it appears that the patient has or 'owns' two quite separate streams of consciousness. One stream of consciousness can 'know' things that the other doesn't (as show by experiments involving left and right eye, and left and right hand tactile recognition). (The philosopher Thomas Nagel writes about this in his paper, 'Brain Bisection and the Unity of Consciousness' in his book 'Mortal Questions' OUP.)
This shows much more than that consciousness is dependent on the brain. It shows that the very idea of a unitary 'subject' is open to question. Daniel Dennett in his book 'Consciousness Explained' draws a similar conclusion.
As you will discover in the program, there is a form of mind-body dualism, known as 'epiphenomenal dualism' or 'epiphenomenalism', which fully accepts that consciousness is a product of brain processes, while insisting that the conscious experiences 'produced' by events in the brain are ontologically distinct from the world of physics.
Are we sure about reality?
The film 'The Matrix' gives a vivid account of grounds for a Cartesian-like doubt about the external world which does not involve mind-body dualism. What is significant about this doubt is that, unlike the case with Descartes' 'evil demon', the existence of matter is never doubted. Rather, the question is whether the best explanation of my present experience is the one that I have come to accept, that my senses give more or less reliable evidence of where I am and what I am doing. This is where arguably the theory of knowledge and philosophy of mind part company. If you can be a materialist, yet still harbour Cartesian-like doubts, then it would seem that the question of the nature and extent of human knowledge is an additional question that remains after we have established a materialist theory of the relation between the mind and the brain.
The language of brain and consciousness
This section reminds me very much of W.V.O. Quine's essay 'Epistemology Naturalized' (in his book 'Ontological Relativity and Other Essays', Harvard). Quine's starting point is that 'there is no first philosophy'. He dismisses the worry about scepticism (expressed in the previous section) as a mistaken search for 'first principles' of knowledge, when what the philosopher should be looking for is a natural explanation of how knowledge arises, the evolutionary advantage conferred by our ability to form mental representations of the world around us, and so on. This line of inquiry is very similar to pragmatism (Quine comes from the tradition of American pragmatism) in that it gives an account of our ability to form concepts in terms of the way concepts contribute to our practical ability to 'find our way about in the world'.
The purpose of consciousness
Evolution proceeds by chance mutation and natural selection. So in this sense, one would naturally expect diversity. However, the strains that survive will be those that win out in the struggle for survival. So we can always ask, of any attribute, what evolutionary advantage does it confer?
Now this is relevant to the question of epiphenomenalism (cf. above). The epiphenomenalist might argue that the ability of the brain to 'produce' conscious experiences in addition to an organism's demonstrated ability to discriminate and process information about its environment is an example of a non-functional mutation, which confers no survival advantage. It just happens to be the case that organisms such as human beings who have developed language, *also* experience an inner life. In another world, identical organisms might have evolved which did not have an inner life, but who *behaved* just like us. (This is the notorious 'zombie' hypothesis developed by David Chalmers, amongst others.)
Dualism and materialism
The concept of mind as a 'stage in the progression of our brain complexity' need not be dualistic. It is dualist, if we adopt the epiphenomenal approach, and see consciousness as being miraculously produced when brain processes reach a sufficient level of complexity. (In his book, Daniel Dennett reproduces a cartoon with a professor standing in front of a black board covered in algebraic equations. The professor is saying, 'And now a miracle occurs!')
An alternative view is that we are dealing with levels of explanation, the physical, the biological, the psychological, each of which operates with its own independent vocabulary of concepts. The biological cannot be defined in terms of the physical, nor can the mental be defined in terms of the physical or biological. However, just as you would not use the irreducibility of biology to physics as an argument for the existence of 'vital stuff', so one ought not to use the irreducibility of psychology to physics (or to biology) as an argument for the existence of 'mental stuff'.
The concept of soul
I fully agree. Our discussion of the soul is, in Wittgenstein's words, 'a ladder one throws away, after one has climbed up it.' It serves a heuristic function, nothing more.
All the best for 2003,
P.S. Note on 'epiphenomenalism': I am talking here of epiphenomenalism as a metaphysical theory of the nature of the mental, rather than as the view - which you may come across in the literature - about the precise relation between the biological and psychological levels of explanation of human behaviour. In the latter sense, 'epiphenomenalists' believe that the causation from thought to action should be understood on the biological level, with the psychological as a causally ineffective by-product. This view is fully consistent, however, with materialism in the metaphysical sense.