Difficulties with Davidson's account of action (I): On explaining something in terms of the very causes by which it is defined
(by guest blogger Joshua Rust)
It is not uncommon to find philosophers defining otherwise problematic entities in terms of their causes. A plausible reading of Davidson, for example, sees him as defining action as a body movement which is caused by certain beliefs and desires. If the body movement is not caused by these attitudes, it does not count as an action. This is Davidson's answer to Wittgenstein's puzzle—when I raise my arm what is left over when I subtract the fact that my arm has gone up? (Philosophical Investigations, I-621) If the arm-raising is a genuine action, its causes are what remain following the subtraction.
Defining something in terms of its causes is not, of course, limited to philosophical discourse. Motion sickness is, perhaps, a certain queasy feeling that is caused in the right way. If one has the same feeling, but is on otherwise stable ground, that feeling does not count as motion sickness.
Here is my worry: if we define something in terms of its causes, it seems as though we are precluded from then explaining that thing by appeal to those same causes. This is manifestly clear in the case of motion sickness. If explanations are answers to why-questions, I may not cite motion in answer to the question, "Why am I experiencing motion sickness?" Why not? Because a condition of something's being an explanation is that it is genuinely informative. James Woodward, for example, says that a scientific explanation aims to "draw attention to further considerations the relevance of which is not apparent from [the why-question's] original characterisation of the explanandum under investigation" (Woodward 1979, 61; see also Mumford 1998, 139-41, and Braithwaite 1953, 320).
Davidson opens "Actions, Reasons, and Causes" with the following claim: "What is the relation between a reason and an action when the reason explains the action by giving the agent's reason for doing what he did? We may call such explanations rationalizations, and say that the reason rationalizes the action" (Davidson 1963, 685). But given Woodward's non-triviality requirement placed on a causal explanation, if actions are defined in terms of their causes (primary reasons = beliefs and desires), is Davidson then correct to say that a reason causally explains or rationalizes an action? That is, if (action = body movement caused by reason), we may not answer "Why (body movement caused by reason)?" by citing a reason. Reasons are not causal explanations of actions. This seems like a serious flaw with Davidson's account of action.
One possibility is that I've misconstrued Davidson's account of action; he does not define actions in terms of their causes. What is his solution to Wittgenstein's puzzle? Or what are the grounds by which he rejects this puzzle? Another possibility is that Davidson has something different in mind by explanation than does Woodward. But Davidson goes on to say "that rationalization is a species of ordinary causal explanation" (Davidson 1963, 685). As far as I can tell, actions aren't rationalized or causally explained by primary reasons—if anything, only a body movement is so explained. In the next post I will exploit this flaw to offer a non-standard reading of Davidson's account of action.
While this post is nominally about Davidson's account of action, I'm principally interested in leveraging the issue for metaphilosophical purposes. Any author which defines x in terms of its causes may not, if I am correct, then go on to claim that he or she has causally explained x by appeal to those same causes. Searle, for example, defines an institutional fact as a brute fact which has had some function intentionally imposed on it. He cannot, if I am right here, thereby go on to claim that institutional facts are causally explained by the said intentional imposition of function.