Probability in the eye of the beholder?

In his debate with Daniel Dennett on whether science and religion are compatible, Alvin Plantinga asks the following question:

Let D be the proposition that the variety of the living world has come to be by Darwinian processes, E the relevant biological evidence, G the proposition that evolution is guided, and U the proposition that it is unguided. Then our question is which is greater: P(D/E&G) or P(D/E&U)? (Science and Religion: Are They Compatible?, p.12)

"P(D/E&G)" means "the probability of D, given E and G" and "P(D/E&U)" means "the probability of D, given E and U". Plantinga claims that P(D/E&G) > P(D/E&U). His grounds for this claim are:

1. "Clearly God could have created living things by way of natural selection, causing the right mutations to arise at the right time, preserving the relevant populations from disaster, and the like."
2. "The eye, the mammalian brain, and other organs remain difficult problems for unguided evolution."
3. "[T]he stupefying complexity of the living cell, both prokaryotic and eukaryotic."

1 is his reason for thinking that "P(D/E&G) is perhaps not terribly low", while 2 and 3 are his reasons for thinking that "P(D/E&U) is exceedingly low". "Not terribly low" and "exceedingly low" are both vague expressions, but no doubt everyone would agree that "exceedingly low" is lower than "not terribly low". Indeed, Plantinga thinks it is "orders of magnitude lower" .

It is clear that 2 is just the old argument from complexity and 3 is the new(ish) argument from irreducible complexity. Let us put aside the fact that both 2 and 3 have been adequately addressed by evolutionary biologists, and focus on 1 and the claim that "P(D/E&G) is perhaps not terribly low".

If we looked only at the complexity of some aspects or features of life on earth, we might agree with Plantinga's estimation of P(D/E&G). But complexity is not all there is to D. What about the messiness of evolution and all the evolutionary dead ends? If we look at the latter as well, and if we, like Plantinga, understand the "guided" in G to mean "guided by God", where God is supposed to be omnipotent and omniscient, shouldn't we estimate P(D/E&G) to be lower, perhaps way lower, than Plantinga's "not terribly low"? More simply put, what is the chance of God's having done such a lousy job?

The point I have just made is fairly simple; the interesting question is why Plantinga doesn't see it.


Being clever isn't enough

Bernard Williams gave his last interview at Oxford in December 2002, not long before he died. The interview was published in The Harvard Review of Philosophy (Volume XII, Spring 2004), and the editor noted that Williams "did not have the opportunity to correct the transcript of the interview". In any case, it is, though short, a fascinating interview. Anyone who admires Williams would enjoy reading it; anyone who is not familiar with Williams's work but wants to know why he is so admired would too.

I was particularly intrigued by Williams's remarks on being clever and doing philosophy. Williams himself is an exceptionally clever philosopher, but he says:

Another person who had one kind of influence on me --- though I'm glad to say I think she didn't influence me in other ways! --- was Elizabeth Anscombe. One thing that she did, which she got from Wittgenstein, was that she impressed upon one that being clever wasn't enough. Oxford philosophy, and this is still true to a certain extent, had a great tendency to be clever. It was very eristic: there was a lot of competitive dialectical exchange and showing that other people were wrong. I was quite good at all that. But Elizabeth conveyed a strong sense of the seriousness of the subject, and how the subject was difficult in ways that simply being clever wasn't going to get around.

"I was quite good at all that" --- there was presumably a time when he was not aware that being clever wasn't enough, and it took a philosopher he did not otherwise admire to make him see that.

Williams's response to the interviewer's follow-up question "What is required in addition to being clever?" is also edifying:

A good appreciation of what is not there in the argument or on the page, and also some imagination. Many philosophers pursue a line of argument in a very linear fashion, in which one proof caps another proof, or a refutation refutes some other supposed proof, instead of thinking laterally about what it all might mean. There is a tendency to forget the main issue, which is what the distinction that was made was supposed to be doing in the first place. An obvious example is that people used to go on about what the difference is between a moral and a non-moral 'this-that-and-the-other'. What is a moral consideration as opposed to a non-moral consideration? What is a moral judgment as opposed to a non-moral judgment? They belabored these questions without ever asking why the distinction was supposed to be so important in the first place.