La acción humana

And in general every student of nature must hold in suspicion whatever most captures and holds his understanding; and this warning needs to be all the more applied in issues of this kind, to keep the understanding clear and balanced.

Francis Bacon, The New Organon, LVIII, p. 48

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1. No Miracles

The last chapters have been dominated by the niggling idea that the issue of whether theory matches the real world can be judged only from outside theory. But if theory includes all of our best empirical and sci-entific understanding of the world, then the outside position is neces-sarily ‘transcendental’: we could never occupy it, or even get nearer to occupying it, whatever the length and success of our empirical and theoretical inquiries. In chapter 5 this was the principal motive for pre-ferring the quietism of the south-east to the strenuous realism of the north-east. And while plenty of scientists and philosophers of science want to sign up to being called realists, the transcendental nature of the position has often bothered them – we quoted Thomas Kuhn on just this issue in chapter 3, but perhaps the physicist Niels Bohr summed up the attitude best when he said that ‘It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.’ Yet this too is not entirely satisfactory. It may remind one of the boxer who said in his pre-match interview, ‘I can only see it going one way. My way. Of course, how it will actually go I can’t say.’

There is something wrong about this; is there similarly something wrong about taking realism to be so dispensable?

A reasonable realism needs some kind of reinterpretation, and philosophers have tried to provide it. One attractive modern view treats realism not as involving any transcendental comparisons, but as itself an explanatory hypothesis, on all fours with other theoretical explanations already common in science. Realism becomes, as it

were, science’s own theory about itself, and with all science’s creden-tials. This refiguring of realism (intended as real realism) is largely due to two philosophers, Hilary Putnam and Richard Boyd, and I shall call it the Putnam–Boyd transformation.

The idea is that science is treated as an object of study, and we have certain data about it. These data are best explained by realism. The data include first and foremost the overwhelming success science gives us in predicting and controlling events. In order not to beg any ques-tions, success must not here mean ‘success as a realist (alone) conceives it’, that is, some kind of success in corresponding with an independent world of fact. Success means success in the empirical, or practical, or observational domain: the kind of success that even devotees of strange cults recognize when they use their mobile phones and emails, aero-planes and tide-tables. It is a datum that has to be recognized by all par-ties in these debates. It has a second aspect, which is the convergence of informed opinion upon one view, or the gradual shrinkage of questions left open to serious debate. Relativists may mutter about dark forces privileging Western science or male science, but over huge areas there are no real alternatives and no conflicting lines of inquiry. People who are ‘open minded’ about, say, whether the Grand Canyon was formed quite recently by a single flood, are simply ignorant about the way the dating of things is done, and has to be done, and ignorant as well about the certitude of the results that geology and allied sciences bring in.

Such thoughts open the way to the ‘no miracles’ argument for real-ism. Realism is the only philosophy of science that makes this abun-dant and continuing success anything other than a miracle.¹This is a hugely intuitive argument. How come that the aeroplanes stay up, the probes land where they should, the reactions follow their predicted path, and the cures work, unless we are getting something right about nature? If our maps don’t represent the land properly, it will be a mir-acle that we end up where we want to go. Conversely, the fact that we do end up so often where we want to go is best explained by the simple truth that our maps do represent the land properly. So do tide-tables and timetide-tables, and this in turn is all that explains why we use them. They turn what would otherwise be the miracle of success into a humdrum pattern.

The plan, then, is to transform what seemed like a transcendental doctrine of doubtful meaning into a piece of natural explanation, assessable as other scientific explanations are. In this, the Putnam–Boyd transformation resembles other similar strategies in philosophy. For example, one route to general scepticism starts by thinking of us as acquainted only with our own ideas, and then the world outside becomes an unknowable object whose resemblance to our ideas is at best an idle hope. A plausible response is to think of the external world simply as a respectable causal explanation of our pattern of experience. It deserves our confidence because it is the best explanation we have of why the continued order and predictability of experience is anything other than a miracle.

Do we manage to refer to the theoretical entities of science, the atoms, photons, neutrons, forces, fields of energy, whose magnitudes explain things? Certainly. Reference to theoretical entities follows on nicely. For once gravity, viruses or electrons occupy an explanatory role in our thoughts about nature, they will also occupy that role in explaining why we and our predecessors talk as we do about nature, even if our predecessors got bits of it wrong. For that is just one more complex natural phenomenon. Talk is a consequence of sophisticated human beings learning to detect electrons and the rest. And to see our theoretical entities as playing this explanatory role is in effect to see them as the reference of our remarks and our predecessors’ remarks.

The electromagnetic force that deflected his galvanometer also made Faraday say what he did about it, and makes us in turn see him as having referred to it. It would not matter to this that he had some false or superseded views about the nature of the force. And this, inci-dentally, solves the problem that bedevilled Cratylus or Nietzsche about the ‘adequacy’ of words to things. Our words are adequate to things when they represent them as they are, and centrally that requires that what we say best explains our sayings, just as the actual voltage explains the result of a good measurement of the voltage, or a real cliff explains the symbol for a cliff appearing on the map.

So is it as simple as that? What happens if we debate on the ground set by the Putnam–Boyd transformation?