Jason Rosenhouse, of Evolutionblog, has posted a rather snarky review of a book review by the historian and philosopher Ian Hacking that was published in The Nation. Jason titled his comment “How not to defend evolution”. Here’s my take on it.
Jason thinks that Hacking was pretentious, that he was not careful in his use of language, and that he was wordy. The essay was 4600 words long. Jason’s response is 1520 words of part one of a two parter. Hmm…
The problem as I see it lies in the attitude of the sciences (and yes, I include mathematics amongst that tribe) to the humanities, and in particular history of science. As I have noted before, the sciences have a kind of rolling wall of fog at a temporal distance behind them. They only cite those papers that are this side of that wall, or those papers that stand out like mountain peaks from the more distant past. History is messy and interferes with the simplistic story that textbooks (and, let it be said, defenders of evolution) want to tell.
It would be very nice if history was a narrative like Babylon 5, with lots of story arcs that nevertheless move the whole story ahead linearly. It isn’t. There are no pure heroes and no pure villains, and if you want to talk about those who preceded Darwin as well as those who followed him, you have to take them in their own terms first before passing judgement on their ideas.
Hacking knows this, better than most, if not better than anyone else. He was written a lot about the history of science, and his colleague Gordon McOuat has done an enormous amount of historical research on the metaphor of the tree of life, which is a recurring theme in Hacking’s article.
So why shouldn’t Hacking make the points he made? History is something that happened, however much we might want a TV serialisation instead. And what is more, it greatly illuminates the concerns that people have today, on either side (or on any side, for there are rarely just two sides to a story in history). The progress of science is something that has multiple programs, multiple concerns and multiple sides.
Hacking notes that anti-Darwinism is a degenerating research programme. The notion of a research programme (the British spelling is usually used because Imre Lakatos, who coined it, worked in the UK at the time) is pretty crucial to understanding why sciences are able to progress. Lakatos held that a programme that is not generating novel insights, techniques, theories and research goals is moribund, while fruitful programmes do all these things. Since Lakatos developed his views in opposition to Popper’s (and Feyerabend’s) view of science, which is something that ID proponents appeal to a lot, it is not pretentious to mention him – it is crucial. Jason’s criticism is founded on ignorance.
But, as Hacking also notes, Lakatos is not the final word on what is science. It looks very much like science is more complex and interesting than single sloganised views of science, either those of philosophers of science (except mine own, of course, and those I defer to) or of the scientists themselves. And evolutionary biology is more problematic, in the sense that it is much harder to characterise the general requirements of science for evolution, and indeed much of biology, than other sciences like physics or chemistry or astronomy (the main examples of the early philosophy of science literature).
Hacking also rightly notes that the ID movement objects to the idea of chance in evolution. And that this is a hard pill to swallow. It is. Objections to the causal role of, or even existence of, chance date back to the classical era. Unfortunately, Hacking doesn’t mention that consequent – that chance is not all that operates in evolution; nor does he note that the operative definition of “chance” in evolution is “undirected”, not “chaotic”, although evolution can occur when direction is given (say by humans) and a certain amount of chaos is actually necessary for evolution to occur or else selection would only ever act to stablise populations, not change them.
But it is the Tree of Life theme that is most interesting. I disagree with Hacking that the biblical or Jewish uses of tree metaphors are either very interesting or related to our modern conceptions. But we have been using tree metaphors since Aristotle to classify our world, and the idea of genealogical trees developed, as Hacking notes, from biblical interpretation (and from the need to track marriages amongst the aristocracy for purposes of “breeding”, but that’s another story).
The idea that classification is genealogical begins in the 17th century in natural history, and is fully in flower by the early 19th century. The first person to give genealogical trees of species was Darwin, but he had precursors in George Bentham’s use of logical trees (the so-called “Tree of Porphyry”) to classify plant species, and in Karl Ernst von Baer’s developmental trees of shared and unshared developmental sequences between species.
Hacking notes that the idea that we will one day have the “one true tree of life” through modern methods based on evolutionary theory is what sticks in the craw of those who doubt the Darwinian theory. Perhaps it does. It also sticks in the craw of many professional taxonomists. While we may be confident that species actually do evolve from common ancestors with their nearest relatives, the actual path of history is not open to direct inspection, and so such reconstructions of the past must lie in a certain amount of inevitable uncertainty, now and forever. Information is erased by history, and wanting it not to be so doesn’t stop it from being erased. Novel techniques make it possible to identify some of the past, but even they are in the same logical straits as phylogenies based on morphological traits.
It is something of a sin to mention this. The point has been made repeatedly in the history of biology since Darwin, but often those who mention it are regarded as, as Hacking puts it, giving aid a succour to the foe. But here I part company with Jason, and with Kitcher, whose book Hacking is discussing (and which I am in the process of reviewing myself; see the reading list to the left), and side unashamedly with Hacking – why should we “frame” the debate by ignoring very real difficulties and facts about research? How does that strengthen our case. Yes, it is hard to reconstruct the past – this is true of every worldview irrespective of their dogma or methodology. But this is why evolutionary biology is exciting – it allows us to make the attempt, and moreover to falsify past attempts by appealing to more and better data. ID, on the other hand, has no program here; nothing beyond attacks on the perceived or invented flaws of evolutionary biology, as if sniping were a way of doing science.
Hacking rightly notes that Darwin saw this clearly. He even discusses the matter in the Origin:
All the foregoing rules and aids and difficulties in classification are explained, if I do not greatly deceive myself, on the view that the natural system is founded on descent with modification; that the characters which naturalists consider as showing true affinity between any two or more species, are those which have been inherited from a common parent, and, in so far, all true classification is genealogical; that community of descent is the hidden bond which naturalists have been unconsciously seeking, and not some unknown plan of creation, or the enunciation of general propositions, and the mere putting together and separating objects more or less alike.
But I must explain my meaning more fully. I believe that the arrangement of the groups within each class, in due subordination and relation to the other groups, must be strictly genealogical in order to be natural; but that the amount of difference in the several branches or groups, though allied in the same degree in blood to their common progenitor, may differ greatly, being due to the different degrees of modification which they have undergone; and this is expressed by the forms being ranked under different genera, families, sections, or orders.
and later he says
We shall never, probably, disentangle the inextricable web of affinities between the members of any one class; but when we have a distinct object in view, and do not look to some unknown plan of creation, we may hope to make sure but slow progress.
This is exactly what has transpired since. We continue to make progress, even though we will never achieve that mythical beast, the “one true tree”. If it is good enough for Darwin to make this point, why should Hacking be criticised for so doing? The answer is, I believe, due to the framing of the debate by those who think that a certain view of evolution is all-conquering and all-powerful; dare we say it, a “universal acid”?
Yes, everybody frames all debates in certain terms of contrasts. Those who argue for evolution tend to do it too. But evolution is a science, and science is not about truth, not even of trees, but instead is about making progress and learning about the world. To assert that it must be about truth is to make a dogma, to fossilise a view in conceptual amber. Science is a process, not a set of doctrines for assent.
Hacking makes a nice contrast with the “research program” of Michael Behe, who tries to pick holes in the current state of (necessarily incomplete) research in order to boost his own form of anti-Darwinism. There’s no science done here. But likewise the simplified narrative of Kitcher’s about why life in America is so harsh that the religious have to stand against Darwinian ideas is not based on good history, as the volume by Numbers on the history of creationism, and the volume by Leinesch on the Scopes trial indicate. I have not read Leinesch, so I cannot comment on that book, but it seems to me that the Scopes trial was as much about resisting the eugenics movement that was, at the time, allied with evolutionary biology (see the textbook Scopes taught out of, Hunter’s Civic Biology), as it was promoting a religious agenda. It is likely that the harsh and withering prose of Mencken is as much to blame for the increasing divergence between American religious opinion and evolution as anything else. Let us not ignore the fact that in the period from around 1890 to 1920 or so, it was the evolution boosters who tied eugenics in with evolution, not those who wrote The Fundamentals. In one way, Bryan was on the right side.
Jason (and no doubt some other usual suspects) will attack Hacking for not dismissing religious opinion out of hand. Hacking is not religious any more than Dawkins, but he, unlike Dawkins and others, recognises the very real strengths of religion as a way of life. We do not need to deny those strengths to attack the untruths that some of the anti-Darwinians push, although it would be nice if we could offer a secular alternative without the flaws of religion. In fact, I think we can do just that (it is called, unsurprisingly, secularism) in a tolerant society. But that is beside the point here – if we are to argue against religiously motivated attacks on evolutionary science, such as intelligent design or whatever scam (“teach the controversy”, which only exists because they say there is one) they are presently pushing, let us do so by taking into account the history and not by ignoring it.
Hacking has chosen his words pretty carefully (apart from the egregious reference to Genesis, as if that were either here or there), and nothing in his article strikes me, who reads the same source material as Hacking, and who has studied the actual philosophy of science, some of which Hacking wrote the best parts of, as pretentious. If anything, I think it is pretentious of Jason, who obviously doesn’t know the material, to try to critique Hacking. Sure, creationists will mine Hacking for quotes out of context – they may do it to me as well. But what idiots do with honest writing is no reason not to be honest.
Oh, one thing I forgot to mention – Paley never was a Bishop, but at best a subdean. This is a classical philosopher’s error – Hacking has perhaps allowed Bishop Berkeley’s rank to wander across to Paley. A minor mistake.