Explanatory Compatibility and the Argument from Reason

VIII. Unlimited Explanatory Compatibility and the Noncausal View of Reasons
This is a point at which Anscombe, in her brief response to Lewis’s revised argument objects, claiming that Lewis did not examine the concept of “full explanation” that he was using. Anscombe had expounded a “question relative” conception of what a “full explanation” is; a full explanation gives a person everything they want to know about something. John Beversluis explicates this idea as follows, using the string quartets of Beethoven as his example:
Fully means “exhaustively” only from a particular point of view. Hence the psychologist who claims to have fully explicated the quartets from a psychological point of view is not open to the charge of self-contradiction if he announces his plans to attend a musicologist’s lecture on them. In music, as in psychology, the presence of non-rational causes does not preclude reasons. In fact, there is no limit to the number of explanations, both rational and non-rational, that can be given why Beethoven composed his string quartets…All of these “fully explicate: the composition of his string quartets. But they are not mutually exclusive. They are not even in competition.39 This is an explication of the idea of an unlimited explanatory compatibilism. It is further supported if one accepts, as Anscombe did when she wrote her original response to Lewis, the Wittgensteinian doctrine that reasons-explanations are not causal explanations at all. They are rather what sincere responses that are elicited from a person when he is asked what his reasons are. As Anscombe puts it:
It appears to me that if a man has reasons, and they are good reasons, and they genuinely are his reasons, for thinking something--then his thought is rational, whatever causal statements can be made about him.40
Keith Parsons adopted essentially the same position in response to my version of the argument from reason when he wrote:
My own (internalist) view is that if I can adduce reasons sufficient for the conclusion Q, then my belief that Q is rational. The causal history of the mental states of being aware of Q and the justifying grounds strike me was quite irrelevant. Whether those mental states are caused by other mental states, or caused by other physical staets, or just pop into existence uncaused, the grounds still justify the claim.41
But the claim that reasons-explanations are not causal explanations at all seems to me to be completely implausible. As Lewis puts it,
Even if grounds do exist, what have they got to do with the actual occurrence of belief as a psychological event? If it is an event it must be caused. It must in fact be simply one link in a causal chain which stretched back to the beginning and forward to the end of time. How could such a trifle as lack of logical grounds prevent the belief’s occurrence and how could the existence of grounds promote it?42
If you were to meet a person, call him Steve, who could argue with great cogency for every position he held, you might on that account be inclined to consider him a very rational person. But suppose that on all disputed questions Steve rolled dice to fix his positions permanently and then used his reasoning abilities only to generate the best-available arguments for those beliefs selected in the above-mentioned random method. I think that such a discovery would prompt you to withdraw from him the honorific title “rational.” Clearly the question of whether a person is rational cannot be answered in a manner that leaves entirely out of account the question of how his or her beliefs are produced and sustained.
As for the question of explanatory compatibility, the issues related to the question of whether one causal explanation can exclude one another or whether they can be compatible is rather complex. But in the case of the string quartets of Beethoven, surely the example is a flawed one, because what is being discussed here is different aspects of the composition. The urge to compose them requires a different explanation from the decisions Beethoven made about what melody to compose, how to put the harmony together, and so on. If Beethoven was obsessed with writing for string instruments, we still do not know why he chose quartets as opposed to, say, cello solos.
Second, it seems clear that there have to be some limits on explanatory compatibility. Consider how we explain how present came to appear under the Christmas tree. If we accept the explanation that, in spite of the tags on the presents that say Santa Claus, the presents were in fact put there by Mom and Dad, this would of course conflict with the explanation in terms of the activity of Santa Claus. An explanation of disease in terms of microorganisms is incompatible with an explanation in terms of a voodoo curse. In fact, naturalists are the first to say, “We have no need of that hypothesis” if a naturalistic explanation can be given where a supernatural explanation had previously been accepted.
Further, explanations, causal or noncausal, involve ontological commitments. That which plays an explanatory role is supposed to exist. So if we explain the existence of the presents under the Christmas tree in terms of Santa Claus I take it that means that Santa Claus exists in more than just a non-realist “Yes, Virginia,” sense.
Even the most non-reductivist forms of materialism maintain that there can be only one kind of causation in a physicalist world, and that is physical causation. It is not enough simply to point out that we can give different “full” explanations for the same event. Of course they can. But given the causal closure thesis of naturalism there cannot be causal explanations that require non-materialist ontological commitments. The question that is still open is whether the kinds of mental explanations required for rational inference are compatible with the limitations placed on causal explanations by naturalism. If not, then we are forced to choose between saying that there are no rational inferences and accepting naturalism. But naturalism is invariably presented as the logical conclusion of a rational argument. Therefore the choice will have to be to reject naturalism.
Lewis maintains that if we acquired the capability for rational inference in a naturalistic world it would have to have arisen either through the process of evolution or as a result of experience. However, he says that evolution will always select for improved responses to the environment, evolution could do this without actually providing us with inferential knowledge. In addition, while experience might cause us to expect one event to follow another, to logically deduce that we should expect one effect to follow another is not something that could be given in experience.
39 Beversluis, Search, 73-74.
40 Anscombe, Metaphysics, 229.
41 Parsons, “Further Reflections” 101.
42 Lewis, Miracles, p. 16.