For many years, the most intensely debated topic in the philosophy of action concerned the explanation of intentional actions in terms of the agent’s reasons for acting. As stated previously, Davidson and other action theorists defended the position that reason explanations are causal explanations — explanations that cite the agent’s desires, intentions, and means-end beliefs as causes of the action [see Goldman 1970]. These causalists about the explanation of action were reacting against a neo-Wittgensteinian outlook that claimed otherwise. In retrospect, the very terms in which the debate was conducted were flawed. First, for the most part, the non-causalist position relied chiefly on negative arguments that purported to show that, for conceptual reasons, motivating reasons could not be causes of action. Davidson did a great deal to rebut these arguments. It was difficult, moreover, to find a reasonably clear account of what sort of non-causal explanation the neo-Wittgensteinians had in mind. Charles Taylor, in his book
The Explanation of Action , wound up claiming that reason explanations are grounded in a kind of ‘non-causal bringing about,’ but neither Taylor nor anyone else ever explained how any bringing about of an event could fail to be causal. Second, the circumstances of the debate were not improved by the loose behavior of the ordinary concept of ‘a cause.’ When someone says that John has cause to be offended by Jane’s truculent behavior, then “cause” in this setting just means ‘reason,’ and the statement, “John was caused to seek revenge by his anger,” may means nothing more than, “John’s anger was among the reasons for which he sought revenge.” If so, then presumably no one denies that reasons are in some sense causes. In the pertinent literature, it has been common to fall back on the qualified claim that reasons are not ‘efficient’ or ‘Humean’ or ‘producing’ causes of action. Unfortunately, the import of these qualifications has been less than perspicuous.
George Wilson  and Carl Ginet  follow Anscombe in holding that reason explanations are distinctively grounded in an agent’s intentions in action. Both authors hold that ascriptions of intention in action have the force of propositions that say of a particular act of F ing that it was intended by its agent to G (by means of F ing), and they claim that such de re propositions constitute non-causal reason explanations of why the agent
F ed on the designated occasion. Wilson goes beyond Ginet in claiming that statements of intention in action have the meaning of
(9) The agent’s act of F ing was directed by him at [the objective] of Ging,
In this analyzed form, the teleological character of ascriptions of intention in action is made explicit. Given the goal-directed nature of action, one can provide a familiar kind of teleological explanation of the relevant behavior by mentioning a goal or purpose of the behavior for the agent at the time, and this is the information (9) conveys. Or, alternatively, when a speaker explains that
(10) The agent F ‘d because he wanted to G,
the agent’s desire to G is cited in the explanation, not as a cause of the F ing, but rather as indicating a desired goal or end at which the act of F ing came to be directed.
Most causalists will allow that reason explanations of action are teleological but contend that teleological explanations in terms of goals — purposive explanations in other words — are themselves analyzable as causal explanations in which the agent’s primary reason(s) for F ing are specified as guiding causes of the act of F ing. Therefore, just as there are causalist analyses of what it is to do something intentionally, so there are similar counterpart analyses of teleological explanations of goal directed and, more narrowly, intentional action. The causalist about teleological explanation maintains that the goal of the behavior for the agent just is a goal the agent had at the time, one that caused the behavior and, of course, one that caused it in the right way [for criticism, see Sehon 1998, 2005].
It has not been easy to see how these disagreements are to be adjudicated. The claim that purposive explanations do or do not reduce to suitable counterpart causal explanations is surprisingly elusive. It is not clear, in the first place, what it is for one form of explanation to reduce to another. Moreover, as indicated above, Davidson himself has insisted that it is not possible to give an explicit, reductive account of what ‘the right kind of causing’ is supposed to be and that none is needed. Naturally, he may simply be right about this, but others have felt that causalism about reason explanations is illicitly protected by endemic fuzziness in the concept of ‘causation of the right kind.’ Some causalists who otherwise agree with Davidson have accepted the demand for a more detailed and explicit account, and some of the proposed accounts get extremely complicated. Without better agreement about the concept of ‘cause’ itself, the prospects for a resolution of the debate do not appear cheerful. Finally, Abraham Roth  has pointed out that reasons explanations might both be irreducibly teleological and also cite primary reasons as efficient causes at the same time. It is arguable that similar explanations, having both causal and teleological force, figure already in specifically homeostatic (feedback) explanations of certain biological phenomena. When we explain that the organism V ed because it needed W , we may well be explaining both that the goal of the V ing was to satisfy the need for W and that it was the need for
W that triggered the V ing.
In a recent article, Brian McLaughlin (2012) agrees that reason explanations are teleological, explaining an action in terms of a purpose, goal or aim for which it was performed. He also agrees that these purposive explanations are not species of causal explanation. However, he rejects the view that these same explanations are grounded on claims about the agent’s intentions in acting, and he thereby sets aside the issues, sketched above, about purpose, intention, and their role in rationalizations. McLaughlin takes the following position: if (i) an agent F -ed for the purpose of G -ing, then, (ii) in F -ing, the agent was thereby trying to G. To assert (i) is to offer an explanation of the action (the F -ing) in terms of the agent’s trying to G . Moreover, if (i) is true then the act of F -ing is identical with or is a proper part of the agent’s attempt to G . Thus, statement (ii) offers what purports to be, in effect, a mere redescription of the act of F -ing. Assuming Hume’s maxim that if an event E causes an event E ′, then E and E ′ must be wholly distinct, McLaughlin maintains that purposive explanations of actions are constitutive and not causal in character.
Michael Thompson has defended a position that makes a rather radical break from the familiar post-Davidson views on the explanation of action. He rejects as misconceived the debates between causalist and non-causalist accounts of explaining action. He does not deny that actions are sometimes explained by appeal to wants, intentions, and attempts, but he thinks that the nature of these explanations is radically misunderstood in standard theorizing. He thinks that desires, intentions, and attempts are not ‘propositional attitudes,’ as they are usually understood, and the ‘sophisticated’ explanations that appeal to them are secondary to and conceptually parasitic upon what he calls ‘naïve action explanations.’ The naïve explanations are given in statements in which one action is explained by mentioning another, e.g., “I am breaking an egg because I’m making an omelet.” It is a part of the force of these explanations that the explanandum (the egg breaking) is present as part of a broader, unfolding action or activity (the explanans: the omelet making). Similarly, “I am breaking a egg because I’m trying to make an omelet,” the explanans (the trying) is itself an action, under a certain description, that incorporates the breaking of the egg. Kindred forms such as ‘ A is F -ing because he wants to G’ and ‘A is F -ing because he intends to G’ are held to give explanations that fall in ‘the same categorical space’ as the naïve action explanations. Thompson’s overall position is novel, complex, and highly nuanced. It is sometimes elusive, and it is certainly not easy to summarize briefly. Nevertheless, it is a recent approach that has rapidly been drawing growing interest and support.
One of the principal arguments that was used to show that reason explanations of action could not be causal was the following. If the agent’s explaining reasons R were among the causes of his action A , then there must be some universal causal law which nomologically links the psychological factors in R (together with other relevant conditions) to the A -type action that they rationalize. However, it was argued, there simply are no such psychological laws; there are no strict laws and co-ordinate conditions that ensure that a suitable action will be the invariant product of the combined presence of pertinent pro-attitudes, beliefs, and other psychological states. Therefore, reasons can’t be causes. In “Actions, Reasons, and, Causes,” Davidson first pointed out that the thesis that there are no reason-to-action laws is crucially ambiguous between a stronger and a weaker reading, and he observes that it is the stronger version that is required for the non-causalist conclusion. The weaker reading says that there are no reason-to-action laws in which the antecedent is formulated in terms of the ‘belief/desire/intention’ vocabulary of commonsense psychology and the consequent is stated in terms of goal directed and intentional action. Davidson accepted that the thesis, on this reading, is correct, and he has continued to accept it ever since. The stronger reading says that there are no reason-to-action laws in any guise, including laws in which the psychological states and events are re-described in narrowly physical terms and the actions are re-described as bare movement. Davidson affirms that there are laws of this second variety, whether we have discovered them or not.
Many have felt that this position only lands Davidson ( qua causalist) in deeper trouble. It is not simply that we suppose that states of having certain pro-attitudes and of having corresponding means-end beliefs are among the causes of our actions. We suppose further that the agent did what he did because the having of the pro-attitude and belief were states with (respectively) a conative and a cognitive nature, and even more importantly, they are psychological states with certain propositional contents. The specific character of the causation of the action depended crucially on the fact that these psychological states had ‘the direction of fit’ and the propositional contents that they did. The agent F ‘ed at a given time, we think, because, at that time, he had a desire that represented F ing, and not some other act, as worthwhile or otherwise attractive to him.
Fred Dretske  gave a famous example in this connection. When the soprano’s singing of the aria shatters the glass, it will have been facts about the acoustic properties of the singing that were relevant to the breaking. The breaking does not depend upon the fact that she was singing lyrics and that those lyrics expressed such-and-such a content. We therefore expect that it will be the acoustic properties, and not the ‘content’ properties that figure in the pertinent explanatory laws. In the case of action, by contrast, we believe that the contents of the agent’s attitudes are causally relevant to behavior. The contents of the agent’s desires and beliefs not only help justify the action that is performed but, according to causalists at least, they play a causal role in determining the actions the agent was motivated to attempt. It has been difficult to see how Davidson, rejecting laws of mental content as he does, is in any position to accommodate the intuitive counterfactual dependence of action on the content of the agent’s motivating reasons. His theory seems to offer no explication whatsoever of the fundamental role of mental content in reason explanations. Nevertheless, it should be admitted that no one really has a very good theory of how mental content plays its role. An enormous amount of research has been conducted to explicate what it is for propositional attitudes, realized as states of the nervous system, to express propositional contents at all. Without some better consensus on this enormous topic, we are not likely to get far on the question of mental causation, and solid progress on the attribution of content may still leave it murky how the contents of attitudes can be among the causal factors that produce behavior.
In a fairly early phase of the debate over the causal status of reasons for action, Norman Malcolm  and Charles Taylor  defended the thesis that ordinary reason explanations stand in potential rivalry with the explanations of human and animal behavior the neural sciences can be expected to provide. More recently, Jaegwon Kim  has revived this issue in a more general way, seeing the two modes of explanation as joint instances of a Principle of Explanatory Exclusion. That Principle tells us that, if there exist two ‘complete’ and ‘independent’ explanations of the same event or phenomenon, then one or the other of these alternative explanations must be wrong. Influenced by Davidson, many philosophers reject more than just reason-to-action laws. They believe, more generally, that there are no laws that connect the reason-giving attitudes with any material states, events, and processes, under purely physical descriptions. As a consequence, commonsense psychology is not strictly reducible to the neural sciences, and this means that reason explanations of action and corresponding neural explanations are, in the intended sense, ‘independent’ of one another. But, detailed causal explanations of behavior in terms of neural factors should also be, again in the intended sense, ‘complete.’ Hence, Explanatory Exclusion affirms that either the reason explanations or the prospective neural explanations must be abandoned as incorrect. Since we are not likely to renege upon our best, most worked-out scientific accounts, it is the ultimate viability of the reason explanations from commonsense ‘vernacular’ psychology that appear to be threatened. The issues here are complicated and controversial — particularly issues about the proper understanding of ‘theoretical reduction.’ However, if Explanatory Exclusion applies to reason explanations of action, construed as causal, we have a very general incentive for searching for a workable philosophical account of reason explanations that construes them as non-causal. Just as certain function explanations in biology may not reduce to, but also certainly do not compete with, related causal explanations in molecular biology, so also non-causal reason explanations could be expected to co-exist with neural analyses of the causes of behavior.