For Oxford Handbook On Free Will, 2 nd ed., R. Kane (ed.) Draft Jan. 25, 2010] This essay will canvass recent philosophical discussion of accounts of human (free) agency that deploy a notion of agent causation. Historically, many accounts have only hinted at the nature of agent causation by way of contrast with the causality exhibited by impersonal physical systems. Likewise, the numerous criticisms of agent causal theories have tended to be highly general, often amounting to no more that the bare assertion that the idea of agent causation is obscure or mysterious. But in the past decade, detailed accounts of agent causation have been offered (chiefly by Randolph Clarke and Timothy O'Connor), and they have occasioned more specific objections in turn.1 These recent accounts and objections to them will be my primary focus in what follows. But first I will identify two distinct motivations that have been advanced for adopting an agent causal approach to human agency and the ontological and metaphysical commitments common to any version of this approach.
I Motivations for an Agent Causal Account
From the Intractable Difficulties with Giving a Causal Theory of ActionMany action theorists have sought informative necessary and sufficient conditions for a behavior's being an intentional action-something the agent did purposely, not accidentally or reflexively. A common strategy starts from the assumption that psychological states such as desires, beliefs, and perhaps intentions are important and 2 salient antecedent causes of action. This strategy was championed by Donald Davidson (1963) and has been the dominant approach ever since. Nevertheless, soon afterDavidson's essay, a number of authors (Chisholm 1966, Taylor 1966, and Davidson 1980 himself) noticed a serious obstacle to attempts to provide a plausible causal theory. It is easy to conjure up scenarios where one's motivational reasons cause one to perform an action suited to the reasons despite one's not having acted intentionally. Here is Davidson's example: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 his hold on the rope he could rid himself of the weight and danger. This belief and want might so unnerve him as to cause him to loosen his hold, and yet it might be the case that he never chose to loosen his hold, nor did he do it intentionally. (1980, 79) Here, the climber has a reason for loosening his hold on the rope, and the reason causes him to do so, but in such a way that it is evident that he did not intentionally so act. The way the reason causes the action was of the wrong sort for the action to have been intentional. The challenge for the causal theorist, then, is to say in general terms what the right way consists in. What kinds of causal process between motivating reasons and behavior must occur for the action to be intentional, according to the causal theorist?Some philosophers have held that there can be no good answer to this question, so that the "prob...