In his blogging, Luke of Common Sense Atheism has made some fairly harsh, and largely unexplained, swipes at reformed epistemology (Alvin Plantinga’s project of trying to show we can accept Christian doctrine without any argument or evidence for doing so), saying things like “reformed epistemology is neither” and that it is a “Candidate for ‘Dumbest idea of the Century.’” He’s also lashed out at atheist philosophers like Russ Shafer-Landau for being willing to take moral realism as just intuitively obvious, comparing them to the hated reformed epistemologists. I want to comment on this, because I think Shafer-Landau’s position on ethics is extremely plausibe, and while I don’t think Plantinga’s philosophy works as a defense of Christianity, I do think that Plantinga is clearly right about some of the points he makes along the way to defending his position. Understanding what Plantinga gets right is important because it will stop atheists from wasting their time on confused criticisms of him, and will improve the quality of their thinking on issues like moral realism.
When I try to talk about these issues, I instinctively reach for Descartes and Hume–I want to say something like “If you look at the fate of their philosophical projects, you’ll see that efforts to provide evidence for everything we believe are doomed to fail.” But a lot of people would be justifiably annoyed by such a facile appeal to famous names, so let me try to be a little more precise:
Descartes: Descartes’ project was to try to forget everything he knew and build up an edifice of certain knowledge from nothing, and he was working with a notion of “certainty” highly influenced by mathematics. Most philosophers now think Descartes’ project was a dismal failure, not only because of flaws in the particular arguments he used (like his attempted proofs of the existence of God, and his insistence that God wouldn’t allow us to be wildly deceived about what the world is like), but also because he set impossible standards for himself: he purports to be willing to consider (and later, able to refute) the possibility of a deceiving demon who has him confused even about the most seemingly obvious mathematical truths, which seems to make impossible Descartes’ attempt to escape skepticism by arguments, because the demon might be tricking him into thinking he has good arguments when he doesn’t (which is plausible in part because lots of philosophers think Descartes didn’t have good arguments).
Hume: Hume was trying to work out the implications of some assumptions about what we can know known as empiricism: all we can know is what we experience directly, and what is logically deducible from our concepts and what we experience directly. As Hume pointed out, very little is logically deducible from what we experience directly–notably, nothing about our future experiences is logically deducible from those experiences. So, if empiricism is true, we don’t know an awful lot of the things we think we know. Though Hume admitted he found this conclusion psychologially impossible to take seriously, he presented it as his official philosophy.
In light of these disappointing predicaments, most analytic philosophers today implicitly adopt an approach to understanding the world radically different than that of Descartes and Hume: instead of trying to start with nothing and passing everything through strict standards of epistemic legitimacy, we just take whatever seems obvious to us as working assumptions until given reason to think a given assumption is mistaken. This isn’t license to go on merrily believing whatever we happened to believe freshmen year; the idea is we have to think about what we can infer from the most obvious truths about the world, and more importantly think about what contradictions there might be in our starting assumptions, and put in the effort figuring out which assumption to jettison when we do find contradictions.
Luke doesn’t give much indication of what his own thoughts on these issues are, beyond “all these people are wrong.” There is one sentence from the moral realism post that does seem to shed some light on his position: “it’s the duty of the person making a claim to prove it is correct.” This sounds like like a conversational norm (if you’re going to tell someone something, you’d better prove it) but my guess is that what Luke really has in mind is a norm governing private belief (if you believe something, you’d better be able to prove it). To extrapolate a little, I would say that Luke’s position resembles that of Descartes and Hume in that he wants there to be a fundamental, quite strict standard to which all belief is held, but a standard which is more meetable than Descartes’ or Hume’s.
If that’s the claim, the key to evaluating it is knowing what “proof” here means. The sort of epistemological position I am defending owes a lot to G. E. Moore (one of the founders of the analytic tradition), and while he rejected the standards involved by the Descarteses and Humes of the world, he did talk about being able to prove things: he thought all you needed to do to prove the existence of an external world was to hold up your hands and say “here are two hands.” The sense of “proof” used here is highly intuitive: normally, if you ask me to prove that I have an X (pair of hands, roll of $100 bills, spaceship, whatever) showing you my X is proof enough. If this is what Luke means by “proof,” then there are a lot of things we have which may be in trouble under Descartes’ or Hume’s standards for what we can believe, but are not in trouble under Luke’s standard.
This “here let me show you” approach to proof is interesting, because it suggests a reason for being much more confident in our knowledge about the physical world than, say, philosophical opinions. But if you think about this for a moment, this is not at all a good thing for Luke’s standard of legitimate belief. Most importantly, it raises the question of how we can believe statements in epistemology, like, “our senses are generally reliable” or “you shouldn’t believe what you can’t prove.” Probably there are interesting ways of understanding “proof” in which such statements are provable, but I would be curious to know what specifically Luke has in mind here (if he does have a well-developed idea in mind). Moore’s approach to these problems was to say that admit that only some of our common-sense beliefs are provalbe, but that there are things we can know without proving. For now, I’m cautiously skeptical of the possibility that any such approach could work.
A better response to Plantinga is just to point out that belief in the Christian God isn’t very much at all like most of the common-sense beliefs commonly cited as threated by Descartes & Hume-style skepticism (like belief in the reliability of our senses), but is an awful lot like beliefs most Christians wouldn’t accept without evidence–namely, the beliefs of other religions. That kind of response is very hard to reject without special pleading on behalf of Christianity, and doesn’t involve commitment to any potentially troublesome epistemic principles.