The elements that go into the causal theory must be intelligible independent of their role in constituting our action. The account of the mental states, the efficient causal relation, and the bodily movements must not make explicit or tacit reference to self-conscious action. Otherwise, the causal theory invokes
version of the causal theory goes the other way, but explaining why turns on metaphysical issues about cause and essence that are irrelevant to my interests in this paper.
62. The mental states are the proximate efficient cause of the movements, not just an efficient cause of them. An account of relevancy must pick out the proximate efficient cause from the chain of efficient causes through time and from the totality of efficient causes and background and enabling conditions at a time. For this paper, the details of that account do not matter. Likewise, my criticism does not depend on any particular metaphysics of causation.
what it means to explain, thereby violating its explanatory burdens. Violations might happen at any of the three points of the explanation. Although I think that in the end violations happen at all of them in a true account of our action, I shall focus my criticism on violations in the account of the mental states. In order to clearly present the kind of criticism I shall pursue, though, I in this section present the problem of deviant causation for the causal theory. While causal theorists acknowledge this problem and discuss it, I think that they do not always appreciate the kind of explanatory challenges that it presents. Getting clearer on it reveals a general explanatory issue with the causal theory.
Davidson himself presents this problem with the following case:
A climber might want to rid himself of the weight and danger of holding another man on a rope, and he might know that by loosening hold on the rope he could rid himself of the weight and danger. The belief and want might so unnerve him as to cause him to loosen his hold, and yet ... he [does not] do it intentionally. ... [S]ince there may be wayward causal chains, we cannot say that if attitudes that would rationalize x cause an agent to do x, then he does x intentionally.
(Davidson [1973] 79) A desire and a belief here combine to efficiently cause bodily movements in such a way as to satisfy that desire. Yet the climber does not act. As we might put it, what happens with him that leads to his partner’s death happens ‘in spite of himself’. The causal theorist thus must distinguish the cases when a belief- desire pair efficiently causing bodily movements constitutes an action from cases when it does not. Otherwise, the account incorrectly counts certain events as actions. At least, one way to understand the problem of deviant causation is as a difficulty about extensional adequacy. Davidson seems to take it this way. He thinks that the problem is that
the action on the one hand, and the belief-desire pair which give the reason on the other, must be related in two very different ways to yield [an action] explanation. First, there must be a logical relation. Beliefs and desires have a content, and these contents must be such as to imply that there is something valuable or desirable about the action. ... Second, the reasons an agent
has for acting must, if they are to explain the action, be the reasons on which he acted; the reasons must have played a causal role in the occurrence of the action. These two conditions on reason explanations are both necessary, but they are not sufficient, since some causal relations between belief-desire pairs and actions do not give [action] explanations.
(Davidson [1982] 173) Causal theorists tend to take up the challenge in the last sentence of this passage, adding to the additive account in ways meant to improve extensional adequacy. They try to specify the kind of causal relationship or the set of mental states in such a way as to rule out deviant cases. Of course, these routes of response are not mutually exclusive. A response that unifies both of them is likely the best course.
I shall not take up these responses, though, because my interest is in a different way to understand the issue behind the problem of deviant causation. After all, extensional adequacy is easy to achieve. Just say that the mental states must efficiently cause the bodily movements “in the right way” and you have extensional adequacy (Davidson [1974] 232). Similarly, just say that the mental states must efficiently cause the bodily movements ‘in the way needed in order for there to be an intentional action’ and you have extensional adequacy. Neither of these accounts are informative, though, and they thereby do not count as an explanation. More to the problem for the causal theorists, neither of them can be part of a metaphysical reduction of our action. The second overtly refers to intentional action. The former is at best a placeholder for the account of efficient causation. Without that account, it tacitly refers to intentional action since ‘in the right way’ just means ‘in the way needed in order for there to be an intentional action’.
The problem of deviant causation is thus not merely about extensional adequacy. Causal theorists need an extensionally and explanatorily adequate account of our action. I shall argue that they cannot offer it because they cannot meet the explanatory requirements of the account. I will not focus on
the problem of deviant causation, though, nor will I consider responses to it. It is an instance of a more general explanatory challenge for causal theorists. Not only do they need to account for the efficient causal relationship, but they need to account for the mental states as well. They must not invoke intentional action in their accounts of both the efficient causal relation and the mental states. I shall argue that they cannot meet the extensional and explanatory goals with respect to the account of mental states. Any set of mental states that is extensionally adequate appeals to the idea of intentional action in one way or another. Any set that does not is extensionally inadequate.