‘Postmodernists nearly all reject classical foundationalism; in this they concur with most Christian thinkers and most contemporary philosophers. Momentously enough, however, many postmodernists apparently believe that the demise of classical foundationalism implies something far more startling: that there is no such thing as truth at all, no way things really are. Why make that leap, when as a matter of logic it clearly doesn’t follow? For various reasons, no doubt. Prominent among those reasons is a sort of Promethean desire not to live in a world we have not ourselves constituted or structured. With the early Heidegger, a postmodern may refuse to feel at home in any world he hasn’t himself created.
Now some of this may be a bit hard to take seriously (it may seem less Promethean defiance than foolish posturing); so here is another possible reason. As I pointed out, classical foundationalism arose out of uncertainty, conflict, and clamorous (and rancorous) disagreement; it emerged at a time when everyone did what was right (epistemically speaking) in his own eyes. Now life without sure and secure foundations is frightening and unnerving; hence Descartes’s fateful effort to find a sure and solid footing for the beliefs with which he found himself. (Hence also Kant’s similar effort to find an irrefragable foundation for science.)
Such Christian thinkers as Pascal, Kierkegaard, and Kuyper, however, recognize that there aren’t any certain foundations of the sort Descartes sought—or, if there are, they are exceedingly slim, and there is no way to transfer their certainty to our important non-foundational beliefs about material objects, the past, other persons, and the like. This is a stance that requires a certain epistemic hardihood: there is, indeed, such a thing as truth; the stakes are, indeed, very high (it matters greatly whether you believe the truth); but there is no way to be sure that you have the truth; there is no sure and certain method of attaining truth by starting from beliefs about which you can’t be mistaken and moving infallibly to the rest of your beliefs. Furthermore, many others reject what seems to you to be most important. This is life under uncertainty, life under epistemic risk and fallibility. I believe a thousand things, and many of them are things others—others of great acuity and seriousness—do not believe. Indeed, many of the beliefs that mean the most to me are of that sort. I realize I can be seriously, dreadfully, fatally wrong, and wrong about what it is enormously important to be right. That is simply the human condition: my response must be finally, “Here I stand; this is the way the world looks to me.”
There is, however, another sort of reaction possible here. If it is painful to live at risk, under the gun, with uncertainty but high stakes, maybe the thing to do is just reduce or reject the stakes. If, for example, there just isn’t any such thing as truth, then clearly one can’t go wrong by believing what is false or failing to believe what is true. If we reject the very idea of truth, we needn’t feel anxious about whether we’ve got it. So the thing to do is dispense with the search for truth and retreat into projects of some other sort: self-creation and self-redefinition as with Nietzsche and Heidegger, or Rortian irony, or perhaps playful mockery, as with Derrida. So taken, postmodernism is a kind of failure of epistemic nerve.’ (Alvin Plantinga, ‘Warranted Christian Belief)
– David Bohm argues in his talk in ‘The Structure of Scientific Theories’ that terms in a given scientific theory only have meaning within the context given by that theory. This can probably be called ‘strong incommensurability’ – no two theories seem to be able to talk to each other.
– What this leaves us with is a kind of private language for science – private theory language. If the terms in a theory have their meaning only within the context of that theory, then it would seem that, as far as theories are concerned, scientists are unable to talk to each other. Given, however, the fact that scientists do talk to each other (and sometimes even about each others theories) there must be a snag somewhere.
– Bohm’s solution (and he later acknowledges that though it looks as if he’s advocating a kind of solipsism, he’s not) is to try and show that until a kind of common language can be adopted, confusions will continue to crop up in theory development. He cites a number of scientific cases from quantum mechanics where confusion abounds. Some familiar examples might be von Neumann, Kepler/Newton, etc.
– I think it’s fair to here identify Bohm to be paying tribute to the positivist tradition (Carnap et al) in his effort to move from ‘private theory language’ to a common kind of language – a project which saw a large reaction in 60’s and 70’s philosophy of science, especially in the area of theory-laden observation, which attacked the idea that there is in fact even neutral sensory data and neutral language to translate a theory from and into.
– Despite significant confusions in science (Bohm is correct to identify this) it seems a bit shaky to assert that this is both something to assert that this confusion is something to be avoided at all costs by adoption of a more neutral language (even though a Wittgensteinian picture of language may be of help here). Such confusions are only a strict problem if they stem only from theories not being able to talk to each other and do nothing to advance science – and quite often, these confusions help to sharpen, clarify and discard theories and concepts and so help science to advance forward.
– An example here that Bohm cites is malaria – which, throughout history, has had many different theories formed about its origin, structure, spreading, etc. Bohm notes that every different theory here is incommensurable – theorized causes ranged from bad air, damp air, etc, which all seemed to be confirmed by the data – and that effectively, each theory had nothing in common other than the fact that each dealt with malaria.
– In rebuttal, Robert Causey argues that far from demonstrating strong incommensurability, this merely shows that some theories are harder to falsify and some easy to confirm. The current (correct) theory of malaria makes sense of the same data as earlier, more primitive theories (damp air, bad water, etc) – Causey more or less argues that the history of malaria shows that, far from being incommensurable, these theories dealt with the same problem and the same data. Causey further argues that to show the kind of incommensurablity that Bohm is driving at, Bohm would have to show that (1) the problems dealt with by the different theories really were different problems with only the mere appearance of being the same (2) that the terms used by the different theories really were different and (3) that the differences in these terms and their meanings are different enough to show that the problems the theories were dealing with really were different problems.
– This, though a crude sketch, shows that incommensurability requires a fairly high burden of proof if it’s going to be asserted in as strong of a form that Bohm asserted.