Here’s my last comment (for now at least) on Gordon & Dembski’s The Nature of Nature. The last chapter is by William Lane Craig, who starts uncontroversially enough by noting the decline of scientific naturalism in philosophy. He catalogues the ascendancy of positivism and verificationism in the field throughout the middle of the twentieth century, and particularly notes the influence of A J Ayer’s book, Language, Truth and Logic. In this Ayer developed (though he didn’t invent) the concept that any sentence not subject to empirical verification is simply meaningless.
Thus any statement dealing with “God” is not simply untrue, but devoid of any significance. Craig indicates, and there seems no reason to doubt him, that such considerations more or less excluded any metaphysical discussion during this period within philosophy. Science became the arbiter of truth in this field as in so many others.
As he goes on to show, however, verificationism excludes much of science. Worse still, it was quickly realised that it refutes itself, because sentences such as “Sentences about supernatural beings are meaningless” cannot be verified empirically. It seems somehow fitting that Ayer himself had a near-death experience at the end of his life which, according to his physician, involved a divine being.
As the century progressed, it seems, the tide turned in philosophy (if not in science) and there has been a resurgence in matters metaphysical, and even the emergence of a significant proportion of theists in the discipline. My purpose, though, is not to comment on the decline of positivism and verificationism, but to wonder why it took so long. I don’t know when the counter-argument mentioned above was first proposed, but it is so obvious that it is hard to imagine that it was not voiced early on. Once voiced, it completely destroys the argument. How could anyone deny that the claim of verificationism is unverifiable, and therefore refuted by simple logic as soon as it is made?
Yet it ruled within the Academy for decades; it excluded not only religion but the whole of metaphysics from philosophical discourse for all that time, and one could not say that its influence has been expunged even now.
Philosophy is therefore a useful test-case for the power of world-views, because it depends entirely on reasoning rather than giving the appearance of being dictated by evidence. In science, especially of course in evolutionary biology, it can be hard to say with any certainty whether naturalistic evolution is demanded by the evidence to form the world-view, or whether the world-view prescribes how the evidence is interpreted and even which evidence is considered. In philosophy the question is clearer: at least for several decades, people saw that one sentence of irrefutable logic destroyed their justification for naturalism, and yet they preferred darkness to light. How revealing.
The slow retreat of naturalism in philosophy does not match closely what happens in other fields, and maybe the appeal to evidence has much to do with this. But as I have shown, it is remarkably hard to evaluate evidence correctly in the face of ones world-view. If nothing else, The Nature of Nature demonstrates that fact starkly, as equally celebrated leaders in the same discipline, coming from different outlooks on the world, dismiss each other’s arguments as “weak” without any clear acknowledgement that they simply disagree on essentials. It’s tempting to suggest that you could hear exactly the same range of views argued in your local pub, without the dense verbiage and footnotes.
It is not only in biology where this process can be observed. In theology, for example, there has been a substrate of naturalism for over 150 years. Is the evidence for form criticism, or for the Documentary Hypothesis, actually good, or is it just the best that a naturalistic view of the Bible can come up with? And how much does that evidence hold up on its own, rather than being bolstered by academic groupthink, the need for respect (or advancement) and so on? Even on such a relatively minor matter as the dating of the New Testament documents, the far-from-conservative J A T Robinson was amazed at just how thin the evidence for the prevailing view was, and how easy it was to make a good case for much earlier dating. Yet that was in 1976, and although his suggestions have never been refuted, they’ve caused scarcely a ripple on the academic scene. Evidence, you see, has to be the right sort of evidence.
I predict that one day supernaturalist theories will once more have a respectable place in every field of human endeavour. Possibly including theology. I also predict that when they do, it will have nothing to do with the presentation of new evidence. Instead, everyone will say that they always knew that’s how things were.