There is one very good reason for thinking this. Consider common sense, and well-established science. On the one hand, it seems absurd,
a mere folly, to question the reality of the objects of common sense and of core scientific theory. On the other hand, seeing ourselves as getting things absolutely right might seem to depend upon the idea of a mythical God’s-eye view, whereby we step outside our own skins and comment on the extent to which our best theory corresponds with an independent reality. Scepticism about any such idea is famously voiced by Thomas Kuhn, whose work The Structure of Scientific Revolutions did much to batter mid-twentieth-century confidence in the objectivity of science and the linear nature of its progress:
There is, I think, no theory-independent way to reconstruct phrases like
‘really true’; the notion of a match between the ontology of a theory and its
‘real’ counterpart in nature now seems to me illusive in principle.4 This characterization of ‘realism’ is found at least from William James to the present. In this way of setting things up 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 scientific under-standing of the world, then the ‘outside’ position is necessarily tran-scendental: we could never get nearer to the feat of occupying it, whatever the length and success of our empirical and theoretical inquiries.
This kind of complaint is often directed at something called ‘the correspondence theory of truth’. This is the idea that truth can be understood and explained in terms of correspondence with the facts.
It is not merely the idea that ‘true’ means ‘corresponds with the facts’;
that may just be a harmless synonym. It makes no difference whether you say that the witness was unreliable, or that what he said failed to correspond with the facts. But for the phrase to work as a philosoph-ical explanation of truth, more is needed. It is needed that ‘cor-responds’ means something on its own, and ‘facts’ are identifiable in some special way, and then we can put them together and see cor-respondence with the facts as a special kind of success. And then it is argued that this requires exactly the idea of ‘stepping outside your own skin’ – on the one hand making a judgement, and on the other hand obtaining a God’s-eye or ‘sideways’ view of both the judgement and the facts, and measuring how well they match.
Well, what is wrong with that? Philosophers of an absolutist or
‘realist’ temper often like to compare the art of the theorist with the art of the map-maker. The analogy has many virtues, and I shall be exploiting some of them later. And you can go and check a map against a landscape. You can find that a cartographer was more or less accurate, more or less thorough, more or less honest about the extent of his knowledge, and more or less diligent in his observations.
There is, similarly, the activity of checking theory against observation.
This is how science advances. But what Kuhn disliked was not this everyday processes of observation, nor, of course, the idea that these are integral to good empirical scientific research. What he disliked was the idea that this checking can be conducted without the use of our best theories and best understandings. It is this idea of a distinct point of view on ourselves, taken as it were en bloc, a measurement of how well we are doing, such as God might make, that is to be avoided.
According to one of his pupils, Professor Elizabeth Anscombe, Wittgenstein was fond of a German saying that translates as ‘You cannot shit higher than your arse’, which encapsulates the same point.
The point comes better into view when we think of an example.
Currently the temperature of the earth’s atmosphere is a cause of great anxiety to many people. It is measured in several ways.
Ordinary mercury thermometers scattered around the land surfaces of the earth are one. Measurements of microwave energies of oxygen molecules by satellites passing over regions of the atmosphere are another, since physical theory holds that such energies vary exactly with temperature. Then there are radio balloons with their own instruments, and a great number of other ‘proxies’: tree-ring growth, or the ratio of deposit of various isotopes in ice samples, for example, which are used to measure historical temperatures. When the measurements do not agree we know that something has gone wrong, but we may not know what. When this is our situation, there is no
‘skyhook’ – no way of peeking round the corner, looking over our own shoulders, asking God – and discovering what the temperature really is, or what it really once was, independently of the techniques
of observation that are on trial. We can soldier on, perhaps with new theories and new techniques, if we can discover them, and that is all.