Nick Spencer reviews ‘The Territories of Human Reason’, by Alister McGrath. 16/05/2019
What to do when your god fails you? Reason had promised to deliver us from the mental slavery of superstition, the exhausting task of making factual bricks without evidential straw. And it did, for a time: the intellectual exodus of the scientific revolution and the Enlightenment transformed the world, or at least the material world. But escaping the baleful priests of Egypt proved easier than settling the Promised Rational Land. Reason, it transpired, was more complex than we imagined.
Alister McGrath will, I guess, need no introduction. His latest book (of how many I cannot fathom) The Territories of Human Reason explores what to do when we wake from our dream of Universal Human Rationality. McGrath argues that we honour reason best by using it in the way most appropriate to its ‘territory’ of investigation. This will probably sound a bit opaque, and to grasp it we must first wrestle with the idea of ‘stratified reality’, a familiar theme in McGrath’s (academic) work.
‘Stratified reality’ is premised, first, on the idea that there is such a thing as reality and that it is ‘one’; there is ‘ontological unity’ to use the jargon. We live in a coherent universe that is open to human investigation; we do not live in an opaque, disordered or dualistic universe, in which one part is wholly different to others, or completely inaccessible to human thought.
That registered, although reality is one, coherent, and investigable, it is not undifferentiated. Rather, it has strata or layers that can, and indeed must, be investigated in different ways. This is on account of the phenomenon of emergence, which McGrath does not talk about in much detail.
Emergence is the idea that material reality assumes different properties at different levels of complexity and organisation. Or, to put in an altogether more colloquial way, that the whole is usually greater than, and different to, the sum of its parts. Emergence can come in different forms, most importantly ‘weak’ (or epistemological) and ‘strong’ (or ontological). The difference is essentially whether emergence is about how we know something, or about the nature of that thing itself. Both have implications for reasoning, but the strong form, in particular, is a disaster for reductionist ways of knowing.
For example, long chain molecules behave differently from isolated atoms; cells behave differently from molecules; organs from cells; bodies from organs; groups from individuals; societies from groups; and so on. Emergence lies behind everything from the changing phases of matter, the flocking of birds, and the development of morality, to the existence of consciousness, the behaviour of crowds, and the structure of cities.
More to the point, for our interests, to try to understand the behaviour of emergent phenomena by breaking them up into their constituent parts, studying the behaviour of each in isolation, putting them back together, and assuming that answer is an aggregate of individual findings, is problematic and usually a failure. It is not that you can’t deploy reason to investigate each. It’s that each phenomenon, or stratum, or level, is a coherent ‘territory’ in its own right, and therefore demands a subtly different approach in its investigation.
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McGrath gives a good example, via the biologist Steven Rose, of stratified reality and the different intellectual approaches it affords. What is going on when a frog jumps into a pond? Well, five biologists, each representing a different sub–division of biology, would explain this most mundane of phenomena in different ways. The physiologist explains that the frog’s leg muscles were stimulated by impulses in its brain. The biochemist points out that the frog jumped because of the properties of fibrous proteins, which enabled them to slide past each other when stimulated by ATP. The developmental biologist locates the frog’s capacity to jump in the first place in the ontogenetic process that gave rise to nervous system and muscles. The animal behaviourist explains the jump as the frog’s escape from a predatory snake. And the evolutionary biologist says the process of natural selection ensures that only those froggy ancestors that could detect and successfully evade snakes survived and reproduced. None is wrong, they simply approach the same phenomenon at different levels.
This leads to what is known as ‘methodological pluralism’, the idea that there are different ways of knowing the same world, and which stands in contrast to the ‘methodological monism’ that is implicit in the idea of The Scientific Method. In the words of Roy Bhaskar, an important influence on McGrath’s work, ‘the nature of the object determines the form of its possible science.’
What this means in practice is the one disappointing element of this book, not because McGrath doesn’t explore it but because he explores it in a comparatively brief way. Take a few of the elements of rational investigation: evidence, theory formation, testing, evaluation, theory choice. Any one of these is open to subtly different approaches depending on the territory of investigation in question.
McGrath is good on theory choice. Do we select one theory above others on account of its correspondence with reality, its internal coherence, its capacity for prediction, its coverage of evidence, its parsimony, it simplicity, its elegance and aesthetic appeal, etc.? Any number and combination of these might work according to whether one is working on a mathematical theorem, a chemical experiment, an observed biological behaviour, a textual claim, a philosophical assertion, or a theological proposition.
Similar questions may be raised of, say, the nature of evidence. Is evidence gathered? If so, from where, by what means, according to which criteria? Do we rely on observation or experimentation? Does it make a difference if it is one–off or repeatable? How far and in what ways should we accommodate anomalies in the evidence? And so on.
These are huge questions and it is unfair to criticise McGrath for not answering them. What he does do, as well as highlighting their existence and significance, is to point out that they are best answered by actual observation of rational activities in practice – watching and analysing how different scientists and other rational enquirers go about their work – rather than by an a priori assertion that this is how Reason works.
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The Territories of Human Reason is, thus, to pursue the metaphor, more of a compass than a map, alerting us to the journeys that await us rather than describing the landscape we travel through. It helps us pick a path between positivism and post–modernism, honouring reason without worshipping Reason.
The result is not only a somewhat chastened attitude to Rationality but also to the idea that we can ever straightforwardly map reality, because, to develop further the metaphor, the book implies that what we need is not one compass, but a whole toolkit of similar looking devices that will help us comprehend and navigate our way through reality. ‘I suggest that we should rather think in terms of the principled colligation of “little pictures”, McGrath writes towards the end, ‘creating a larger picture, a seamless web of cross–relationships – perhaps to be visualised as a panorama, which connects and coordinates these snapshots.’ Or, to change metaphors, perhaps we’re just piecing together a giant jigsaw, with innumerable pieces and no clear picture on the box, motivated by the belief that everything fits together somehow, and that our work demands we attend carefully to the subtly different shape and shades of every piece.
The Territories of Human Reason is published by Oxford University Press.
