Reality Conditions

Monday, June 26, 2006

More on the compatibility of evolution and theism: Reply to Pruss

Loyal readers of this blog may remember that a few months ago I wrote a post critizing a paper by philosopher of religion Alexander Pruss. Briefly, Pruss argued that even if accepting every detail in the naturalistic story told by science on how humans came into existing by evolution, a theist should nevertheless not accept the scientific claim that the theory of evolution explains our existence, because for a theist the true explanation must be the will of God to create us (perhaps operating via a careful setting of initial conditions of the universe), and both explanations are incompatible. I criticized this position because in my opinion it confuses natural explanations with trascendental ones, which in my opinion do not clash, and gave also a couple of specific arguments against it. Go read it for the details..

Now Pruss has found the post and left a comment answering my criticism. I will copy here parts (almost all) of the reply and answer to them in turn, as I think it may be of interest to readers who are unlikely to check comments in old posts (does anybody know how to enable easily a "recent comments" feature in Blogger?)

Pruss says:

I think you make three powerful objections:

1. A scientific theory cannot contradict a theological claim, and specifically no scientific theory can contradict the claim that God created human beings.
2. My argument equally applies against all statistical explanations.
3. Scientific explanations are "in-story" explanations, instead of transcendent ones.

Let's look at these. I think (1) is false. A scientific theory that held that human beings are a mere illusion would contradict each of the Western monotheistic religions, and would contradict the claim that God created human beings. No current scientific theory, I guess, holds that human beings are a mere illusion, but one could imagine such a theory. Most religions make at least some claims that are or were at least in principle empirically testable. Thus, Christianity holds that Jesus's body never rotted in the grave. This is an empirically testable claim. And if something is an empirically testable claim, then is it not the sort of thing science could in principle contradict?

My answer is: I did not claim that scientific theories can never conflict with religious ones (or if it seems I did, then it was sloppy writing). In a more recent post I specifically discuss this question, I mention your same example of Jesus's body as a Christian empirical claim, and I thus decide that Gould's NOMA is an unrealistic proposal. What I had in mind is that a specific scientific theory, which makes reference to the natural order and testable properties of it, cannot contradict the particular religious claims that there exists a God who trascends altoghether the natural order and who created it and humans by way of it. Perhaps I should restric my claim to "realistic" scientific theories excluding bizarre counterexamples like the humans-as-illusions one, although I am not sure if the latter is a scientific theory –lots of details ought to be fleshed out on what does "illusion" mean in that context. This aside, I don't see how a theory describing the natural world can contradict a religious claim describing something trascendental to it. The story analogy sets a clear distinction here, in my opinion.

Going on:

As for (2), whether this is so depends on difficult theological questions. My argument applies in every case in which a statistical explanation is being offered for something that God specifically intended to bring about. Now some theologians, especially of a Calvinist stripe, think that everything that happens was specifically intended by God. But other theologians think that God does not specifically intend everything he foresees will happen. Thus, he might specifically intend initial conditions and laws of nature, without specifically intending each of the consequences. Some of the consequences are ones that God, perhaps, does not care about because they are morally neutral. A lot of non-Calvinist theologians think that God does not, for instance, intend any evil states of affairs. It is crucial to my argument that God specifically intends a human species to exist. How do we divide up the universe into the things God intends and the things God doesn't intend? I have no idea. But if one thinks that God doesn't intend evil states of affairs but does intend at least some good states of affairs, and I think most theists who are not of a Calvinist-style persuasion think this, then one is committed to a division. The principle of double effect is relevant here--one can foresee an effect without intending it.

OK, I must confess that being ignorant of much of theology, I had thought the disctintion between "intended" and "nonintended" effects of creation to be more implausible than you show it to be. Still, I think my argument holds some weight. You are commited not only to making that distinction and separating the whole universe between those two classes, but also to rejecting that scientific theories give correct explanations for all things in the first category –only for those in the second ones. Let’s say that God "intended" a beautiful mountain that arised from tectonic plate movement, but "forsaw but did not intend" an earthquake caused by the same movement. Even if the two events receive similar geological explanations, you must say that the scientific account is explanatory only for the latter and not for the former. This strikes me as strange.

Now (3) is, I think, the most powerful objection. But in a way it's not an objection. One of my suggestions was that we could weaken evolutionary theory to keep all the causal claims but drop the ambitious explanatory claims. You are suggesting that science never makes the ambitious explanatory claims. I think this isn't right, but if it were, it would simply mean that scientists have already followed this recommendation, and not just in biology but in all the sciences.

But I think (3) isn't right, either in the case of all science or just evolutionary biology. Most biologists, I suspect, think that evolution refutes Paley-style teleological arguments that start with the complexity of biological organisms and claim that God's will is the best explanation. Now if evolution does not actually provide "true" explanations, then evolutionary "explanations" are irrelevant to refuting Paley-style teleological argumentation. Moreover, if scientific explanation is not real explanation, then inference to best explanation becomes of dubious value, and if you take the (controversial) view that inference to best explanation is central to science, scientific realism is endangered.

Scientific explanation is really continuous with a lot of ordinary, daily-life explanation, where we say that the milk went sour because it was left out and that the wind blew down the sign. If scientific explanation is not "true" explanation, then neither are daily-life explanations. And now the view becomes rather like occasionalism. Occasionalism holds that there are no real causal connections between events in this universe, but God does everything directly. The striking of the match doesn't cause the fire, but when God is pleased to have the match struck, then God is pleased to cause the fire. The view in question is the same, except that instead of denying physical causation, it is explanation that is denied.

I think there is a slight misunderstanding here. I said that scientific explanations are "in-story" ones, but in my view that does not make them "untrue". They are just the appropiate explanations at the natural level, and completely fine as they stand. I am actually not a religious person, tending to be sometimes weakly agnostic and sometimes more strongly disbeliever in any trascendental real; so I would hardly embrace the view that natural science does not "really" explain things. I see science's business as investigating this natural world in which we live, and providing natural explanations for the facts in it. I also believe that if there is another level to reality it is unknowable for us. The believer thinks he knows that another level exists, and that our natural world is related to it in a way describable with the story-author analogy. For him there is a different level of explantion, one in terms of a trascendental deity and its intentions. I would think that in the story analogy the two levels of explanation are not conmensurable; to say that Othello killed Desdemona because Shakespeare decided it is not a "deeper" or a "truer" explanation than to blame it on his jealousy and Iago's scheming. It is an explanation in a whole different level. But even if you are commited theologically to say that God is the ultimate and deepest explanation (at least for those things he "intends") I think you can admit that this is not the kind of explanation that is relevant for science, and with which scientific theories can be weighed against. I don't see my position as close to occasionalism at all; I actually think that you are being cuasi-occasionalist in the specific case of evolution (and all other things intended by God) while I see all scientific and ordinary explanations, which I agree with you in viewing as continuous, as capable of being perfectly true; they are (for theists) complemented by the trascendental ones, not contradicted by them in any case. (Of course, there are religious doctrines like Creationism which do not set God's activity on the trascendental level but frame it explicitly involving empirical claims; but we are both agreed in rejecting this and accepting all ordinary facts of evolution)

You say against this that if evolution is set as refuting Paley-style design arguments then it is clearly a competing explanation with the theological one. I think what really happens is that the Paley argument is an argument ad ignorantiam; it points to some features of the world and says "there is no scientific explanation for this". Evolution refutes this claim by providing such a scientific explanation, but even if evolution was empirically false (imagine for example the universe had turned out to be too young for evolution to have proceeded) the inference to God as best explanation would in my opinion still not be a scientific one. Hume's refutation of the design argument preceeds Darwin in a century, after all, and I find it convincing. Without evolution we would be stuck with a feature of the world with no scientific explanation, so science would have to accept living beings as a brute fact of the universe, as we might accept elementary particles now. It would be no business of science to infer from this a trascendental designer.

Going back to the main point, perhaps the whole disagreement is pragmatical in the end, on how to use "explanation". As I said recently, I suspect many philosophical disagreements are of this kind. I think your use of "explanation" in a way that allows clash between "in-story" and trascendental ones is inconvenient. Going back to the geological example, you are bound to tell geologists (if you believe God intends mountains but not earthquakes, which I am suggesting just as an example) that they cannot be Christian and hold that geology provides a real explanation for mountains; they ought to "drop their ambitious explanatory claims" in the case of mountains but not in the case of earthquakes, even if from a scientific standpoint they recieve parallel explanations. This must be baffling for them! Of course, perhaps you would not insist in this kind of thing except for evolution of intelligent creatures, for which God's intention is a central theological doctrine. But anyway I don't think this is a good idea. It is creating a rift at the scientific level between people like Ken Miller and people like Richard Dawkins, when their disagreement is in fact only at the metaphysical level. I think that given how the incompatibility of evolution and theism is being used as a battlecry for creationsim, to which Miller and Dawkins are allied in opposing, this is not a wise move.


  • I'm with you part of the way. It certainly is true that where religious systems move away from the purely metaphysical and make claims about the physical world, they become testable and liable to challenge from scientific alternatives which may be more predictive, more inclusive, better confirmed. Scientific theories are also not mere Baconian inductive inferences, generalizing on facts, but do come with some sort of metaphysical claims about what reality looks like (e.g., the existence of atoms or fields). You are again absolutely right that for any given scientific theory, the metaphysics isn't necessarily closed to expansion -- one could always add in additional metaphysical baggage to make it conform with one's preferred religious viewpoint. As such, evolution, or any other scientific theory can be made consistent with any religious or metaphysical viewpoint that does not entail observable consequences inconsistent with those entailed by the theory.

    BUT, doing this is metaphysically expensive and ad hoc. The 20th century philosopher of science Imre Lakatos (a student of Karl Popper) argues that you can judge between two competing theories on the basis of their modifications over time. If a theory begins to grow in scope wihtout major changes to its core principles and encompasses more and more phenomena, natural occurances that it was not originally designed to handle, then the theory is progressive. On the other hand, if it requires major modifications to its pivture of the world, especially ad hoc modifications designed for the sole purpose of sweeping under the rug troublesome wrong predictions or entire intellectual regions that it did not foresee, then the theory is degenerate. Lakatos argues that we should always prefer progressive over degenerate theories. You are right that evolution does not require metaphysical materialism. But if you take a naturalistic viewpoint and compare it with an orthodox theistic standpoint, we do seem to have a case where one is progressive and one isn't. Just becuase the consistency is there, doesn't mean there isn't good reason to reject the combination.

    By Blogger SteveG, at 1:27 PM, June 26, 2006  

  • This site gives you advice about how to enable recent comments. However, it only shows comments to posts displayed on your main page, which doesn't help with the comment to an old post problem you experienced. I guess these aren't such common occurrences, and you can reproduce them in a new post if you feel like it.

    By Blogger david, at 2:46 PM, June 26, 2006  

  • On a tangent, an illusion can not be part of a scientific theory. Imagine a stick halfway submerged into water at an angle, it looks as if it bends, yet it doesn't. The archetypical example of an illusion.
    What then is an illusion? Something appears different from how it is. Yet scientifically that very appearance, if described as part of the scientific theory is as it is as well (that is, it is a phenomenon among phenomena that is psychologically different to us).
    Imagine a being perceiving in some part of the electromagnetic spectrum where the refractive index of water is 1, to them the same situation containing the same phenomena, which they can meassure in the same way as we can (e.g. using equipment sensitive to the range of light we call visible) would not contain any illusion.
    Whether or not a certain physical phenomenon is an illusion is not an inherent fact to the phenomenon in the context of the physical theory but depends on the perceptory preconceptions of the observer.

    By Anonymous fh, at 5:15 PM, June 26, 2006  

  • Steve, I agree with much of what you say. If we look at religion as a Lakatosian research program, then it certainly appears like a degenerate one -backtracking over the centuries to leave more and more ground to science and secular society. However a religious person could contend that this is a bad way of looking at religion. They could say that there is a deep human need for something like some kind of religion, and that the prgress of religion over time -moving from crudely anthopomorphic gods that intervene in nature to a purely trascendental deity- is progress in refining the best way to meet this need in ways compatible with other things we value.

    Is this defense -which I write in a "devil advocate" sort of way- sound? I don't know. As an atheist I would rather hope religion to be a contingent phenomenon that may disappear with scientific and social progress, as the good old heroes of the Enlightment thought, instead of a deep need which is part of the human condition. I for one feel little of that need. But the near-universality of religion across cultures and the way new crazy beliefs like New Age rise when traditional religions decline make me pause and think that perhaps we will always have religion around in some form or another. In that case I think fostering those varieties of religion which are compatible with science (and with tolerance and other liberal values) is a worthwhile enterprise.

    By Anonymous Alejandro, at 7:10 PM, June 26, 2006  

  • David, many thanks for the tip. I will try to install it soon.

    fh, I think the scenario Pruss was suggesting was something like "what if we discovered that we are connected to the Matrix and all we think is real is a simulation?" I agree with you that from an external standpoint there is no "illusion" -there is an objective description of everything in terms of the computer program and its hardware basis. But we would probably call our world an illusion if we made this discovery. Then again, David Chalmers has an interesting paper arguing that we would not.

    By Anonymous Alejandro, at 7:19 PM, June 26, 2006  

  • Philosophicaly the brain in a tank scenario was indeed first used to argue that we would not.
    Basically this touches on a different point, internal vs. external observations. It's the opposite of the stick example (and intuitively more unsetteling) relative to our internal perception it is not an illusion, even though to an external human observer it might appear as one.
    To me it's more of a psychological scare scenario than a clean philosophical argument.

    Interesstingly it presumes the identity of the external and internal observer and presupposes on some level that the boundary delinating the inner world and the outer world can be traversed. You can wake up from the matrix, and you are still you, that is human identity is not considered illusionary even in the Matrix. Otherwise it wouldn't be scary.

    By Anonymous fh, at 1:35 PM, June 27, 2006  

  • I think it is basically bible literalists who have a problem with accepting evolution as fact.

    I am not a christian. I am an atheist actually. But most people I know who believe in god have no trouble incorporating scientific information like evolution into their god belief.

    The theory of evolution just becomes god's way of doing things in their eyes.

    And evolution doesn't attempt in any way to deny the possible existence of any of the god concepts.

    By Blogger beepbeepitsme, at 4:57 AM, August 01, 2006  

  • My argument allows for some events to be both intended by God and explained by a scientific explanation. Any deterministic scientific explanations are no problem at all. Likewise, indeterministic scientific explanations involving high probability are OK, because God can, as it were, set up the initial conditions, and then "sit and watch" (well, having foreknowledge, he doesn't have to actually sit and watch) to make sure the desired result comes out (and intervene if it doesn't). Indeterministic scientific explanations involving low probability (the chance that specifically humans would evolve was no doubt small) are where the big problem is--for there, there is a high probability that things wouldn't work out as God wants it to, and hence a high probability that God would have to intervene.

    Here's an oversimplified version of the argument: Could God make a roulette wheel come out at the number 13 at random? I suspect not. For if God made it do that, it wouldn't be random--and God can't do what is self-contradictory. The point is like the old argument that God can't make someone freely do something--by definition, the action wouldn't be free then (this is an oversimplification).

    By Anonymous Alexander Pruss, at 12:20 AM, September 18, 2006  

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