As some may know, I am writing a couple of book chapters to try to sell a proposal to a publisher for The Nature of Classification, a book I am coauthoring with Malte Ebach. I bring the philosophy and he brings the knowledge. However, this means I am not devoting much in the way of brain cells to extraneous blog posts right now. And I feel that I am letting you down. You need something to disagree with from me, or else you may as well just go read PZ.
So I have been thinking of the relationship of theism to evolution lately. As you know, I have a paper in long gestation arguing that theism and evolution – the whole schtick of Darwinian evolution by random mutation and natural selection and stochastic drift, etc., not some cut-down version in which God intervenes in an otherwise clockwork process from time to time – are mutually compatible. One day my coauthor may complete his half and we can submit it. But here are the issues as I see them:
There is the deist option: Deism has several meanings but the one that is most relevant here is that God set up the world with its laws and initial conditions, pushed the Big Red Button, and retired, permanently. It then mechanically evolved, astronomically and biologically, and here we are. The problem with this, is that this god is not the god of theism, who has a plan. This deity is not providential, but the deity of Epicurus and Lucretius:
For all the gods must of themselves enjoy
Immortal aeons and supreme repose,
Withdrawn from our affairs, detached, afar:
Immune from peril and immune from pain,
Themselves abounding in riches of their own,
Needing not us, they are not touched by wrath
They are not taken by service or by gift.
For the deist option to work, evolution must be predictable and inevitable, if we are to be the plan of the deity. This is the view put forward by Simon Conway Morris and those who concur with him; life has a “deep structure” that means that all evolving pathways must converge upon similar solutions, and one of those solutions is, well, us. So the deist option involves two constraints: either god is not providential or his providence consists in creating a world in which humans are inevitable, and if the latter, evolution is predictable and limited in its outcomes.
But many think that evolution is not predictable. In Gould’s famous metaphor, if you rerun the tape of life, each time you would get a different outcome. This is counterfactual thinking, of course – we cannot test this in the large, although we can do limited experiments. There is a problem with those, though; they tend to be very limited. If a selective breeding experiment consistently tricks on a single outcome, is that because the prior state of the initiating genome has limited options, or because there is only one way to solve that “problem”? There’s nothing very deep about finding that the weighted clown stands upright each time; it is hard to make it do anything else. This doesn’t imply that every object in the world will tend to do one and only one thing, let alone stand upright.
The motivation for a “periodic table of life”, to use George McGhee’s term from the book linked above, seems to be physicism. This is a label I just invented (or probably reinvented) to denote biologists who think biology has to be just like physics. The logic runs roughly: since biology is a science, and sciences have deep regularities that are unique to them, biology must have deep regularities that do not reduce to other sciences. Ergo there are deep regularities in evolution. Now it is very likely that there are deep regularities in biology: they are at the very least, regularities of physics. The reason why we do not have solutions involving compounds of neon is that neon doesn’t form compounds under biologically realistic conditions. And there are abstract regularities in biology: Mendel’s law and natural selection are two examples. Both of these involve abstracting away from the physical properties involved in any one case and giving a level of description and explanation that are independent of the substrate properties (see Goode and Griffiths 1995, for example).
But that there are some purely biological constraints that are neither abstract nor reducible to physics, a view sometimes called structuralism, is a hard position to maintain, and that is needed to make the deist view consistent with a purely Darwinian evolution. By “Darwinian”, of course, I mean the modern set of theories, not some slavish devotion to selectionism or Darwin’s own views, although I will argue that he is pretty acute on this topic. I shall call the position that Conway Morris and collaborators adopt the convergence option.
Now, is the deist option available for ordinary theists? Can a Christian be a Darwinian? By this I do not mean, can a Christian compartmentalise their beliefs from their science, nor can they trim either their science or their religion, but are the two positions even compatible? Can one be, to steal a phrasing, fully theist and fully scientist? Is homoousias possible? Are science and religion of one substance? Obviously some think they are mutually incompatible, while others think they are totally compatible. But what I am concerned with is this: can one rationally hold that the core teachings of theism are true, and yet not modify in any way the results and best hypotheses of science? The “rational” part is crucial here. There are all kinds of irrational ways, such as the God of the Gaps, or simply science denialism like creationists.
What is a “core” teaching of theism? We cannot simply specify that theism equates to a literalistic interpretation of the Bible, the Q’uran, or the writings of Ayn Rand. We need to appeal to some philosophical theology. Generally, I take theism to mean at least the following things:
1. There is a deity independent of the physical/created world.
2. That deity is a providential deity, with a plan that it implements towards an end.
3. That deity has the ability to do this, and has so done. That is, the deity has intervened in the physical world.
4. The outcomes are therefore, in some sense, designed.
Now, several things mitigate against theism from the scientific domain.
One is that if you have a purely physical explanation for an outcome X, then the explanatory role for god in producing X is no longer necessary. For example, we do not need to appeal to God’s actions to produce babies in explaining fetal development from a fertilised zygote. A purely physical account is all that we require. This is the Excluded God from the Gaps argument. Once a gap has been filled by knowledge, God is not needed.
Another is that if there are uncaused outcomes, either by randomness or by spontaneous generation (in the broader than biology sense), this, too, mitigates against a deity that is supposed to be competent and sufficient to explain outcomes. The First Cause argument, where God is needed to set things in motion (literally, in Aristotle’s version), becomes otiose. So if evolution involves random outcomes and causes, or if the universe is such that you cannot specify a determinate set of boundary conditions that will always cause a certain outcome even if you are god or Laplace’s Demon, as quantum mechanics currently suggests, then to accommodate the theist creator with science means that either unguided causation has to go or god has to be constrained by the laws of physics. Either way, this is not something a traditional philosophical theist would want to adopt.
Is the convergence option acceptable? Apart from prior metaphysical prejudices that it must be true, I fail to see how it can be supported by modern science. Biology is the science of the contingent, and the empty “spaces” in structure that are touted as evidence for it are a lot less convincing the more broadly one considers biology. Conway Morris, for instance, thinks that multicellularity is inevitable once life evolves, but basically this is because he thinks that life is roughly synonymous with cellularity, and once you have single units, of course multiple unit ensembles become a formal possibility. This needs no structuralist to tell us that. But is life necessarily cellular? Ours happens to be, but the necessity is unproven. Moreover, are eyes going to be inevitable? Well maybe if you get something like animals with nervous systems, but plants “sense” light fine without eyes, and so I see no necessity there, either. Animal-centrism is question-begging. So is vertebrate-centrism, tetrapod-centrism and so on. If you phylogenetically bracket the outcomes, then of course some outcomes are relatively likely, but that was what we were debating in the first place, whether the phylogenies are necessary. Conway Morris thinks phylogenetic thinking is wrong; I think he does it all the time and doesn’t even realise it.
So the deist option is out for a traditional theist, and the convergence option is at best unconvincing and at worst question-begging. No, actually at worst it is complete nonsense, but I think that some aspects of convergence are true, but only if you can bracket the options phylogenetically, which is to say, on the basis of contingent historical development.
Therefore, I reject both options as accommodations between theism and science. In the next of this series, I will suggest another way how a theist can rationally accommodate the two. It is not, I suspect, the only way to do so, but all we need for it to be a rational position is one option that works. However, it may not be something that the ordinary Christian or Muslim could appreciate or fully accept.
Conway Morris, S. 2003. Life’s solution: inevitable humans in a lonely universe. Cambridge: Cambridge University Press.
Conway Morris, S. 2008. The deep structure of biology: is convergence sufficiently ubiquitous to give a directional signal? West Conshohocken, PA; Edinburgh: Templeton Foundation; Alban.
Goode, R., and P. E. Griffiths. 1995. The misuse of Sober’s selection of/selection for distinction. Biology and Philosophy 10 (1):99-108.
Ruse, Michael. 2000. Can a Darwinian be a Christian? : the relationship between science and religion. New York: Cambridge University Press.