Roger Caldwell on science and truth.
This collection of papers is centred overtly on the question of reductionism. However, in its course, it touches importantly on a good many standard philosophical issues, such as the mind-body problem, the concept of self, freedom versus determinism, all seen from the vantage point of the latest developments in science. To those unacquainted with the larger works of Roger Penrose or John Barrow, or the importance of Gödel’s proof and of Turing machines, this is a suitable place from which to start. Indeed, for anyone with an interest in the interface between science and philosophy this is one of the richest brews on offer, all in little over 200 pages.
The symposium is unfashionable (or perhaps merely sensible) in one respect: none of the contributors – with the exception of W.F. Clocksin who attempts to relate science and myth from a Jungian viewpoint – pays any regard to the neopragmatist/postmodernist line that science presents only a series of metaphors akin to poetry and provides more ideology than truth. Of course, science does present us with metaphors, but it also brings about the deaths of metaphors. That of the Big Bang has won out over that of the Steady State which, with our current knowledge of the universe, is unlikely ever to be revived. The presumption of the writers here is the reasonable one that science has added permanently to our knowledge. What remains in question is not whether science offers us a body of truth – which it clearly does – but whether all truth may be reduced to scientific truth.
Here the one hard-headed unabashed representative of scientific reductionism is P.W. Atkins who argues that, given the progress already observed in science, we can have no real reason to suppose that there are limits to scientific explanation. In principle, all of human experience can be reduced to scientific formulae. This is reductionism with a vengeance, whereby poetry, philosophy, religion disappear at once as offering at best mere sentimental consolations, and the province of truth becomes the sole domain of the scientist. This attempt at a scientific takeover, however, is, to say the least implausible. Not only do most of the things we know to be true (from “This bill needs paying” to “John Major is Prime Minister”) have nothing evidently to do with science but also it is hard to see either that they need to be or, indeed, could be somehow more firmly based by science. Even if this could be achieved, such wholescale reductionism, as Mary Midgley argues, would be wholly useless. The physicist has nothing useful to say about the categories in which we live our daily lives. Our world of human institutions like money, pubs and symphonies in C major is no doubt dependent ultimately on the laws of physics but is in no way explicable by them.
No doubt, in principle, biology is reducible to chemistry, and chemistry to physics. But Darwinian natural selection, say, operates on a level where explanation in terms of particle physics is an irrelevance. There is, further, a discontinuity between physics and biology in that the former is not bound by the arrow of time whereas the latter is. Unlike physics, biology is an essentially time-directed, historical science, just as we ourselves are timedirected, historical creatures. Further, as John Barrow points out, to know the ultimate laws of physics is not to possess the ability to predict the outcome of those laws. They may be necessary to understand the world but they are not sufficient. We have yet to find a solution to the equations out of which emerges England, Roger Caldwell, and what I shall say in my next sentence. The limits of such solutions may be either practical (as in chaos theory where a sort of superdeterminism prevails but where prediction involves an impossibly precise knowledge of the starting- conditions) or inherent (as in quantum mechanics where causality has been replaced by statistical probability).
It should be pointed out too that to know the ultimate laws of physics – which, in principle, explain everything – is not at the same time to give an explanation of those laws. Atkins is honest enough to admit that there is a gap here, that science can only claim complete success when it has accounted for the emergence of everything from absolutely nothing. To tell the story of the Big Bang is not enough. For Atkins the cosmologist must next concern himself with what happened on “the other side of zero”. Atkins, with his scientific optimism, is confident that the physicists will deliver the goods. Others may be less blithely confident.
For many readers, however, the peculiar value of the book will lie in scientific concerns this side of zero – which is, after all, where we all live – and in particular in what it has to say about human beings. Science is happier with brain-states, which it can measure, than states of mind, which it can’t. Hence the tendency to reduce the latter to the former. Hao Wang suggests that this is taken too often as a justified assumption rather than the unreasoned presumption that it actually is. Clearly, there are many cases in which brain-states can reasonably be correlated with mind-states, but it may be that there are limits beyond which it isn’t plausible to take a psychophysical parallelism, that there are states of mind which are irreducibly mind and cannot be correlated with anything else.
Such questions are often put at a level of abstraction which is not obviously congruent with our experience of an evolving self interacting with others in an unpredictable world. Here Gerald Edelman (at least in Oliver Sack’s admirable précis) emerges as the hero of the hour. Out from the barren wastes of Artificial Intelligence Edelman has modelled a creatively interacting being that could develop into something with a sense of self. It is one of the uncomfortable legacies of Cartesianism that the ghost in the machine refuses, quite, to go away. Daniel Dennett, among others, has recently derided this privileged observer, the little homunculus secreted somewhere in the brain, somehow holding all the tangled threads together. Of course, he is nowhere to be found, and the tendency is to go to the opposite extreme, and to hold that the sense of a self is mere illusion. Quite where this leads us, however, is obscure, for to have the illusion that one has a sense of self appears to imply a self which has that illusion in the first place.
These are deep waters, indeed, and it may be that Edelman’s ‘neural Darwinism’ offers an attractive way out. For Edelman, the brain not only makes maps of the outside world, it also maps its own mappings, continually recategorises its own categorisations, yielding ever more generalised pictures of the world. The sense of self emerges in this endless recategorisation of the contents of primary consciousness. Admittedly, it is a ‘fuzzy’ sense of self that emerges, but that too corresponds to the sense we all have of ourselves, however we may be perceived by others. The emergent self is, as Oliver Sacks here puts it, like an orchestra without a conductor which is continually making its own music.
What, however, of the question (which for most writers on Artificial Intelligence is less a question than an axiom): Is the brain a computer? Here it is stressed that it is precisely in their inferiority to computers that our brains give us our capacity to adapt and survive. It is all the things we most complain about – the imprecision of our concepts, our forgetfulness, our inconsistencies – that give us our superiority over computers. To have a perfect memory, to have a rigid system of categorisation in a changing unpredictable world is, in Darwinian terms, a recipe for extinction. We must be grateful for the ‘fuzziness’ of our minds which gives us a possibility of survival when computers fail. It is not one of the smallest achievements of this unusually rich and wide-ranging symposium that it offers ways of better understanding – and of being grateful for – the limitations of what it is to be a human being.
© Roger Caldwell 1996
Nature’s Imagination – The Frontiers of Scientific Vision edited by John Cornwell (Oxford University Press, £16.99)
A collection of poetry by Roger Caldwell, called This Being Eden will be published in the near-ish future by Peterloo Press