A Review of J.L. Schellenberg's New Book

...The Wisdom to Doubt: A Justification of Religious Skepticism, came out the other day at Notre Dame Philosophical Reviews, here. I haven't yet picked it up, but I understand it's a "must-read" book in philosophy of religion. It's the second of what he projects to be a trilogy on foundational issues in philosophy of religion. The first was entitled, Prolegomena to a Philosophy of Religion (NDPR reviews it here), and the forthcoming third volume is entitled, The Will to Imagine: A Justification of Skeptical Religion. All three are published with Cornell University Press.

J.L. Schellenberg is a prominent philosopher of religion, known primarily for his seminal book-length exposition and defense of the problem of divine hiddenness, Divine Hiddenness and Human Reason. He is also known for his articles on the problem of evil and the problem of religious diversity.

P.S., He did an excellent job defending the argument from divine hiddenness against the philosopher Jeff Jordan, here (scroll down to the bottom).

Linda Zagzebski

...has a novel and interesting paper defending the rationality of religious belief, based on a Foley-style argument from intellectual trust in oneself and others. It can be found at her department webpage at the University of Oklahoma, here. It's the one entitled, "Is it Reasonable to Believe in God?" The paper doesn't look to be published yet, but has only been delivered in the form of a quasi-popular talk.

Zagzebski remains one of the leading philosophers of religion. The other papers there (not to mention her books) are well worth reading.

Michael C. Rea

...is a young "star" philosopher at Notre Dame who specializes in metaphysics. He's especially known in this field for his work on the problems of material composition -- e.g., the problem of how two or more material things could compose a new thing (I know this sounds like a trivial problem, but believe me, it's a very hard problem. To see why, read Peter van Inwagen's seminal book, Material Beings). However, he is also a Christian, and a young star in the field of philosophy of religion. For example, he is known for using ideas from his work on the nature of material composition to attempt to give a coherent account of the doctrine of the trinity. He's probably best known in recent years for his book, World Without Design: The Ontological Consequences of Naturalism, which, as you may have guessed, is a critique of naturalism (and a very rigorous one at that). I remember reading it in grad school while still a Christian (still with dreams of infiltrating academia and contributing to the "revolution" in philosophy of religion that began with the advent of Alvin Plantinga's work). He has also recently co-authored a primer text in philosophy of religion with Michael J. Murray, (dazzlingly entitled) An Introduction to the Philosophy of Religion.

Here is the link to Michael Rea's department webpage. He also has a good many papers online, a number of which are in philosophy of religion, here. He's does excellent and careful work in philosophy of religion, so his work is well worth reading.

P.S., If you download his cv, you'll see that he has a bunch of books and papers in the field of philosophy of religion that are forthcoming.

Notes on Draper's Article on Behe's Design Argument, Part 5: Are Indirect Routes Really Too Improbable?

I. Review
We've seen that Behe's argument turns on two key claims:

(i) Some biochemical systems are irreducibly (very) complex

(ii) Irreducibly (very) complex systems can't plausibly be accounted for in terms of evolution.

Thus, if one rebuts (i.e., shows false or otherwise contrary to reason), or at least undercuts (i.e., undermines the evidence for), (i) or (ii), then one has shown that Behe's argument is a failure. We've seen that Draper has offered apparently decisive criticisms against (i), and thus has already defeated Behe's argument. However, Draper goes beyond this and offers two main criticisms of (ii) as well -- i.e., he argues that evolution can produce a biochemical system even if it's irreducibly complex. In the current installment, we'll focus on Draper's first main criticism of (ii).

II. Behe's Argument Against Indirect Pathways
Recall the two routes or pathways that evolution can take to producing a given biological system -- direct and indirect -- and that an indirect evolutionary pathway is one that creates a system by changing either its function or its mechanism (or both). Further, recall Behe's claim that it's extremely improbable for an irreducibly complex system to be created via an indirect evolutionary pathway.[1] Why are we supposed to think this? Behe's answer consists in an analysis of one possible kind of indirect pathway, which can be stated in terms of a two-stage developmental sequence:

Stage 1: Two or more separate, independent systems arise, whether reducibly complex or irreducibly complex.

Stage 2: Once they are all "up and running", the parts from these different systems begin to interact, thereby becoming parts of a new system performing a new function.

Behe then argues that this indirect pathway to an irreducibly complex system is too improbable to be a plausible explanation. To see why, recall Behe's original definition of irreducible complexity:

(IC1) A system S is irreducibly complex if and only if:

(i) S is composed of several interacting parts
(ii) S's parts are well-matched
(iii) removal of one or more of S's parts would cause S to cease functioning

Now in our previous installments on Draper and Behe, we focused on the way in which Behe exploits clause (iii) of IC1 to argue against the evolution of irreducibly complex systems. But in his argument against indirect routes to irreducibly complex systems, he exploits clause (ii): that the parts are well-matched; that is, the parts are tailored to one another in such a way that the size, shape, etc. of each part is much better-suited to interact with the relevant other parts than if they had different sizes, shapes, etc.

With these ideas before us, we're now in a position to understand Behe's argument for why indirect pathways to irreducibly complex systems are too improbable to be a plausible explanation: if the system in question is irreducibly complex, then by clause (ii) of (IC1), its parts are well-matched. But if so, then the move from stage 1 to stage 2 would require the parts to be well-matched before they could interact in a way for the new, irreducibly complex system to function. But tailoring the parts to make them well-matched takes time, and the new system would be non-functional until then. But if so, then evolution would eliminate the system before that ever happened. Therefore, it's too improbable for an indirect evolutionary pathway to get us from stage 1 to stage 2.

III. Draper's Criticisms
What to make of this argument? Draper makes two points in his reply. First, even if Behe is right, he can't reach this conclusion with the notion of well-matched parts in clause (ii) of IC1. For, at least in principle, a system might perform its function at least poorly without well-matched parts, and so the new system at stage 2 could do so for a time, in which case it would be functional while evolutionary processes finished fine-tuning the parts of the system until they are well-matched. Thus, in order to block this possibility, Behe would need to revise his account of irreducible complexity again, such that an irreducibly complex system's parts aren't just well-matched, but irreducibly well-matched. Since we saw last time that he has aleady revised (what we're calling) IC1 once before to (what we've called) IC2 (to some handle criticisms of his argument in the literature), we'll call the new definition 'IC3':

(IC3) A system S is irreducibly complex if and only if:

(i) S is composed of several interacting parts
(ii') S's parts are well-matched to such a degree that even fairly minor alterations to their shapes, sizes, etc. would cause S to cease functioning
(iii') A subset x of S's parts are such that removal of one or more of x's parts would cause S to cease functioning

This brings us to Draper's second point: even the irreducible well-matchedness of parts in a system that satisfies IC3 isn't sufficient to put indirect routes to irreducibly complex systems beyond reasonable probabilities. For while Draper grants that Behe's own example of an indirect pathway to such a system may well be ruled out if we assume IC3, there are lots of other possible indirect pathways to irreducible complexity that Behe doesn't discuss, and these haven't been shown to be beyond reasonable probability -- even assuming their parts are irreducibly well-matched. Draper sketches the relevant pathway here as follows:

"The sort of route I have in mind occurs when an irreducibly complex and irreducibly specific [his expression for our 'irreducibly well-matched'] system S that serves function F evolves from a precursor S* that shares many of S's parts but serves a different function F*. Notice that parts that S and S* share and that are required for S to perform F need not be required for S* to perform F* even if they contribute to F*, and parts that are irreducibly specific relative to F may only be reducibly specific relative to F*. Thus, both S* and the specificity of its parts may have been gradually produced via a direct evolutionary path. Then one or more additional parts are added to S*, resulting in a change of function from F* to F. And relative to F, the parts and their specificity, which had not been essential to F*, are now essential."[2]

In sum, even if Behe could solve the worries for his claim that at least some biochemical systems are irreducibly complex, his other key claim -- that such systems can't arise via evolution -- is undercut.

But Draper doesn't end his criticisms here. In the next and final installment, we'll see that Draper undercuts Behe's claim that direct evolutionary pathways to irreducibly complex systems are impossible.
[1] "Even if a system is irreducibly complex (and thus cannot have been produced directly), however, one can not definitively rule out the possibility of an indirect, circuitous route. As the complexity of an interacting system increases, though, the likelihood of such an indirect route drops precipitously." Behe, Darwin's Black Box, P. 40.
[2] Draper, "Irreducible Complexity and Darwinian Gradualism: A Reply to Michael J. Behe", Faith and Philosophy 19:1 (2002), pp. 3-21.

Plantinga vs. Tooley

A nice review of Knowledge of God -- the written debate between Alvin Plantinga and MIchael Tooley -- has just come out in Notre Dame Philosophical Reviews. I haven't yet picked up a copy of the book, but it's definitely a must-read for those interested in philosophy of religion.

Michael J. Murray

...is a Christian theist who does interesting work in philosophy of religion. You can read most of his articles by going to his department webpage. I especially look forward to his two forthcoming books he lists there. He looks to be working seriously on two key worries for theism that go back to at least Hume: (i) the problem of animal suffering, and (ii) naturalistic accounts of the nature and causes of religious belief.

P.S., it's worth reading his exchange with William Dembski on Dembski's intelligent design stuff, here and here.

What God Would Have Known...

 ...is the title of J.L. Schellenberg's forthcoming book , which offers a large number of novel arguments against Christian theism. I...