Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=rcjp20 Canadian Journal of Philosophy ISSN: 0045-5091 (Print) 1911-0820 (Online) Journal homepage: https://www.tandfonline.com/loi/rcjp20 Agent causation as a solution to the problem of action Michael Brent To cite this article: Michael Brent (2017) Agent causation as a solution to the problem of action, Canadian Journal of Philosophy, 47:5, 656-673, DOI: 10.1080/00455091.2017.1285643 To link to this article: https://doi.org/10.1080/00455091.2017.1285643 Published online: 02 Feb 2017. Submit your article to this journal Article views: 532 View Crossmark data Citing articles: 2 View citing articles Canadian Journal of PhilosoPhy, 2017 Vol. 47, no. 5, 656–673 https://doi.org/10.1080/00455091.2017.1285643 Agent causation as a solution to the problem of action Michael Brent department of Philosophy, university of denver, denver, Co, usa ABSTRACT My primary aim is to defend a nonreductive solution to the problem of action. I argue that when you are performing an overt bodily action, you are playing an irreducible causal role in bringing about, sustaining, and controlling the movements of your body, a causal role best understood as an instance of agent causation. Thus, the solution that I defend employs a notion of agent causation, though emphatically not in defence of an account of free will, as most theories of agent causation are. Rather, I argue that the notion of agent causation introduced here best explains how it is that you are making your body move during an action, thereby providing a satisfactory solution to the problem of action. ARTICLE HISTORY received 19 february 2016; accepted 18 January 2017 KEYWORDS The problem of action; effort; agent; causal powers; agent causation 1. Introduction One way to understand the problem of action is to explain the difference between those bodily movements that you are making happen during an action and those that happen without your making them occur.1 For instance, falling down is something that you do when slipping unintentionally. In such unfortunate circumstances, as you are slipping and falling the movements of your body are passive insofar as you are not making them occur – they are precisely not movements that you are causing. By contrast, walking to the café because you want pastry is something that you do intentionally. In situations like this, as you are walking to your desired destination the movements of your body are active insofar as you are making them happen – they are movements that you are causing. Recent philosophical tradition assumes that the key difference between such bodily movements resides in their respective causal history: the bodily movements that you are making happen while acting are causally © 2017 Canadian Journal of Philosophy CONTACT Michael Brent michael.brent@du.edu CANADIAN JOURNAL OF PHILOSOPHY 657 initiated and sustained by antecedents of a particular type. Different versions of the traditional view specify different types of events as the necessary antecedents, but they all share a common assumption: namely, that the antecedents in question are mental events.2 Thus, typical solutions to the problem of action are reductive in at least two related ways: first, they explain the causation of your bodily movements in terms of the occurrence of the relevant mental events, and second, they assume that your action can be explained in terms of causal relations among events, rather than in terms of what you are doing. My primary aim here is to present a new solution to the problem of action. The solution that I offer rejects the reductive ambition inherent in traditional views. In their place, I argue that when you are performing an overt bodily action, you are playing an irreducible causal role in bringing about, sustaining, and controlling the movements of your body, a causal role that is best understood as an instance of agent causation. Thus, the solution that I propose employs a notion of agent causation, though emphatically not in defence of an account of free will, as most theories of agent causation are.3 Rather, I intend to show that the notion of agent causation introduced here best explains how it is that you are making your body move during an action, thereby providing a satisfactory solution to the problem of action. The outline of the paper is as follows. In Section 2, I sketch the problem of action, the typical solutions to that problem, and two serious objections that such solutions face, that of deviant causation and the absent agent. I argue that even if the problem of deviant causation was solved, so long as typical solutions claim that your bodily movements are caused by your mental events, they face a significant problem: if they accept that your bodily movements are caused by your mental events, then they must assume that you are identical with the relevant mental events. But this assumption, I claim, is implausible on metaphysical grounds, so we must conclude that it is not the case that your bodily movements are caused by your mental events. I suggest that the underlying source of this problem is the account of causation that typical solutions assume to be correct, where causation is a relation among discrete events, in conjunction with the assumption that the causally relevant events are your desires, beliefs, intentions, and other mental events. Because typical solutions assume that when you are performing an action your bodily movements are caused by your mental events, I claim that they inadequately explain how it is that you, a particular persisting physical object,4 are making your body move when acting. In Section 3, the irreducible causal role that you play when performing an action is introduced, which I explain in terms of exerting effort, and in Section 4, I provide an account of causation that supports the solution to the problem of action presented in Section 5. I end by describing that solution and noting a few of its salient features. 658 M. BRENT 2. The problem of action, deviance, and absence With respect to the overt movements of your body, the problem of action is that of accounting for the difference between passivity and activity, that is, the difference between those movements that are merely happening and those that you are making happen during an action. The standard attempts at solving this problem suggest that the difference between such events resides in their particular causal ancestry: your overt bodily movement is something that you are making happen when it results from and is sustained by the correct type of causal antecedent. Although the details vary among them, typical solutions assume that the causal antecedent in question is some kind of mental event, such as a desire, belief, or intention.5 Thus, insofar as they explain the causation of such movement not in terms of anything that you are doing but just in terms of the causal roles occupied by the relevant mental events, the prevailing attempts at solving the problem of action are reductive. The standard solutions face well-known objections. One serious objection is that they cannot solve the problem of deviant causation. The problem is that of specifying the necessary and sufficient conditions under which your mental events are causing the corresponding movements of your body so that what is taking place is an action that you are performing, rather than something that is merely happening to your body.6 For example, imagine a scenario in which you want to rid yourself of the weight and danger of holding another person on a rope, you believe that by loosening your grip on the rope you might achieve this result and so you come to intend to do just that, but the occurrence of your belief, desire, and intention frighten you so much that they cause you to loosen your grip.7 In this case, the occurrence of these mental events causes you to loosen your grip and thereby bring about the intended result, but when your hands are loosening their grip on the rope this is not something that you are making happen – rather, like slipping and falling to the ground, such movement is happening in a way that you are not causing, as the causal consequence of other events. In order to solve the problem of deviant causation, proponents of typical solutions must specify how, exactly, your desires, beliefs, intentions, and other mental events are causally related to the corresponding movements of your body so that what takes place is an action that you are performing. Moreover, they must do so in a way that differentiates situations in which you are causing that movement to happen from situations in which the same type of movement happens in a manner that you are not causing. Numerous attempts have been made to specify the right kind of causal relation, but there is yet no response that is generally accepted as correct.8 For present purposes, the upshot of the problem is this: because typical solutions assume that causation is a relation between discrete events, the problem of deviant causation suggests that there is no way to differentiate between movements of your body that are merely happening and those movements that you CANADIAN JOURNAL OF PHILOSOPHY 659 are causing while performing an action. For according to typical solutions, in both situations the same kind of thing takes place: the movements of your body are occurring as the causal consequence of your mental events. In the case of deviant causation mentioned above, because the movement of your hands results from an intervening mental event of nervousness that you are not causing, you are not causing that movement to occur, either. But, notice that even in cases where deviant causation is absent, the relevant movements of your body result from a mental event that you are not causing, so that, here too, even in the absence of deviant causation you are not causing the movements of your body. Thus, from the perspective of the relevant causal interactions typical solutions assume that you occupy the same causal relation to your bodily movements while performing an action and while such movements are merely happening: in both the movements of your body are happening as a causal consequence of your mental events, so in neither case are you causing the movements of your body. As a result, without a specification of how your mental events are causing the corresponding movements of your body when you are performing an action, in contrast to when such movements are merely happening, typical solutions to the problem of action fail to explain the very difference they were intended to illuminate. To make matters worse for such solutions, even if the problem of deviant causation were solved, a deeper worry remains. So long as such solutions assume that your causal role is explained in terms of your mental events, a solution to the problem of deviant causation does not thereby provide an account of how it is that you are causing the relevant movements of your body while acting. Given that typical solutions assume that the causally relevant events are your mental events, and given that your mental events are not something that you are causing, an absence of deviant causation does not ensure that you are causing the movements of your body. A similar worry has been expressed as an additional and more significant objection to typical solutions, that of the absent agent.9 This objection runs as follows: Whenever you are performing an overt bodily action, you are making your body move. When you are making your body move, you are playing a causal role in initiating, sustaining, and controlling the movements of your body. Since the standard solutions to the problem of action depict such movement as caused by the occurrence of the relevant mental events, the objection is that such solutions fail to ensure that you are playing any causal role in producing your own bodily movements when acting. Thus, consider the following remarks by David Velleman and Jennifer Hornsby, respectively: In [standard solutions to the problem of action], reasons cause an intention, and an intention causes bodily movements, but nobody – that is, no person – does anything. Psychological and physiological events take place inside a person, but the person serves merely as the arena for these events: he takes no active part.10 660 M. BRENT The problem now would seem to be that agency cannot be portrayed in a picture containing only psychological states and occurrences and no agent making any difference to anything ... [U]nless there is an agent who causes whatever it is that her action does, questions about action-explanation do not even arise.11 According to Velleman, typical solutions to the problem of action depict your relation to the movements of your body as you are performing an action in a problematically passive way. You are the arena or location in which the relevant mental events take place, and you function like an inactive observer of those events, present only insofar as the mental events in question are attributed to you as their subject. According to Hornsby, the situation is worse. It is not merely that the standard solutions depict you as a passive bystander who merely bears witness to your own bodily movements when acting, but you are entirely absent from the picture. Since the movements of your body while acting are caused by the relevant mental events and not by anything that you are doing to make this happen, there is no sense in which you are making your body move, and so there is, in fact, no action in view here at all. If Hornsby is correct, at their best, typical solutions depict your bodily movements as a mere effect of prior events, rather than as an action the bodily movements of which you are making happen. In light of this objection, defenders of typical solutions have attempted to explain your causal role in terms of the occurrence of a special mental event. Velleman, for example, claims that your causal role just is the proper functioning of a desire to act in accordance with reason.12 Similarly, according to Michael Bratman, your causal role is played by a special kind of intention, which he describes as a temporally extended higher-order policy that specifies which motives you should treat as reasons when deliberating about what to do. Crucially, your causal role in the production of your own action consists in the proper functioning of this intention.13 Velleman and Bratman provide good examples of typical solutions because they are explicitly offering a reductive account of your causal role: you are causing your own action in virtue of the proper functioning of a special desire or an intention that causes that action to take place. For both, a complete explanation of your action need not mention you at all, except by way of the fact that your body is moving in a particular manner as the causal consequence of the occurrence of mental events to which you are subject. Thus, both retain a commitment to the core claim in typical solutions to the problem of action, namely, that the relevant causal antecedent is a mental event. Unfortunately, addressing the problem of the absent agent by adding a special desire or intention, or any other kind of mental event, does not change the underlying fact that such mental events alone are causing the movements of your body while acting. Unless proponents of typical solutions claim that you are identical with the causally relevant mental events, given the conception of causation that they assume to be correct, it follows that you are not playing any causal role when initiating, sustaining, and controlling the movements of CANADIAN JOURNAL OF PHILOSOPHY 661 your body during an action, and so the problem of the absent agent remains unaddressed. That is to say, if causation is a relation among discrete events, and if your mental events are causing the relevant movements of your body during an action, then, in order to ensure that you are playing a causal role when moving your body during an action, proponents of typical solutions must claim that you are identical with the causally relevant mental events. However, it is implausible on metaphysical grounds that you are identical with your mental events, so it follows that your mental events are not causing the relevant movements of your body during an action. Thus, typical solutions to the problem of action are in trouble. I suggest that the source of this problem is the fact that typical solutions assume that causation is a relation between discrete events. Velleman, for instance, explicitly assumes that causation is a relation among events. As a result of this assumption, he thinks that the only way to account for your causal role when moving your body during an action is to assume that your role is occupied by your mental events, so that your causal role in producing your bodily movements during an action just is a relation between your mental events and the corresponding movements of your body.14 As I argue below (Section 5), because typical solutions share this assumption, they fundamentally misconstrue how it is that you are making your body move when acting, for they cannot incorporate the fact that particular persisting physical objects, rather than events, are capable of causing an effect. As a result, such solutions fail to recognize the fact that, as a particular persisting physical object, you are doing something when making your body move during an action. I will claim that you are making your body move by manifesting a causal power that you possess, which I will describe in terms of exerting effort. By highlighting the function that exerting effort plays during the performance of overt bodily actions, I will argue that your causal role in producing your bodily movements when acting cannot be reduced to a causal relation between your mental events and the corresponding movements of your body, and I will show how recognizing this irreducible causal role provides a nonreductive solution to the problem of action. 3. Effort introduced In this section, by describing the role that exerting effort plays during the performance of an overt bodily action, I motivate the claim that when you are moving your body while acting, your causal role cannot be accounted for in terms of a causal relation between your mental events and the corresponding movements of your body. Although often overlooked in discussions of action-theoretic issues, effort is a familiar and widespread feature of daily life.15 Perhaps the most striking examples of effort involve bodily actions that demand physical strain and endurance, such as giving birth to a child, finishing a marathon, or lifting and holding a heavy object in the air. When you are lifting and holding 662 M. BRENT a heavy object in the air, for instance, you are exerting effort in the process of moving the relevant limbs and contracting the muscles that you are using while doing so. Successfully doing so involves exerting effort in at least three ways. First, assuming that you begin lifting the heavy object while it rests on the ground, lifting it off the ground requires that you exert effort, however minimally. At the outset of any such action, effort is exerted when contracting and straining the relevant muscles as you begin to move the object. As with the movement of any object located near the surface of the earth, lifting a heavy object requires that you overcome the causal effects of those physical forces that are impinging upon all objects at all times, and you are doing so, in part, by exerting effort. Second, while you are in the midst of lifting the heavy object off the ground, your ongoing exertion of effort is sustaining that movement for its duration, sometimes while overcoming muscle fatigue or pain. Third, through your ongoing exertion of effort you are controlling the ways in which the relevant capacities of your body are remaining in motion, for instance increasing or decreasing the pace of the bodily movements that you are performing, or varying the intensity or degree of effort that you are exerting in the process. Put in slightly more general terms, by exerting effort you are initiating, sustaining, and controlling the activity of the relevant bodily capacities as you are lifting the heavy object, thereby setting in motion the relevant parts of your body, sustaining those bodily movements over time, and controlling the way in which they are occurring until the action has come to an end. As this example aims to show, when you are performing a bodily action such as lifting and holding a heavy object in the air, the effort that you are exerting while moving the relevant limbs and straining against the weight of that object is not a mental state, event, or process, or in any sense mental.16 Exerting effort is not like volition, willing, or trying to perform an action, as such notions are often understood.17 Brian O'Shaughnessy, for instance, claims that trying is a mental action the performance of which causes the relevant movements of your body. He thinks that every bodily action that you succeed in performing is identical with the simultaneous occurrence of two events: the mental action of trying to perform that bodily action, along with the corresponding movements of your body, where the former event causes the latter event to take place.18 The notion of effort introduced here is importantly different. As the above example highlights, the effort that you are exerting when moving your body and overcoming the weight of the heavy object is distinctly causal, and in the case of such overt bodily actions it is distinctly physical, borne out by various parts of your body during your performance of the action in question. In addition, although your exertion of effort is causally independent of the occurrence of your mental events, causal independence does not entail that your mental events play no explanatory role with respect to what you are doing.19 Crucially, then, when you are exerting effort while moving your body you are causing an action to occur as an effect of what you are doing. Equally as important, the exertion CANADIAN JOURNAL OF PHILOSOPHY 663 of effort is attributed to you, the agent performing the action in question, as something that you are doing, rather than to any of your mental events. I return to these points below (Section 5), after a brief interlude in which I describe a metaphysical framework that supports the alternative solution to the problem of action defended here. 4. Manifesting causal powers – an interlude In this section, I outline the main features of a metaphysical framework that supports the alternative solution to the problem of action introduced below. The framework itself is not one that I shall defend, as it has been defended at length elsewhere.20 Rather, the goal is to apply the framework to the case of agents and the actions that they perform and thereby provide a new solution to the problem of action, as well as further expose the limitations within typical solutions. The framework stands in contrast with a common way of thinking of the metaphysics of causation within philosophy of action, if not more generally. That common conception of causation assumes that causation is a relation between discrete events. The occurrence of one event, the cause, is followed by the occurrence of another event, the effect, and the relation between the events is asymmetrical, nonreflexive, transitive, and presupposes a general regularity or law of nature relating events of that type.21 In contrast, the alternative framework does not share the assumption that causation is a relation between discrete events, nor that the relation is asymmetrical, nonreflexive, transitive, and presupposes a general regularity or law of nature relating events of that type. Rather, the guiding idea is that causation is the manifesting of causal power by particular persisting objects, rather than a relation between discrete events that presupposes a general regularity or law of nature relating events of that type. Thus, the alternative framework illuminates the sense in which causation is a singular process wherein particular objects are manifesting specific causal powers and producing effects unique to the conditions at hand. Within this framework, events are relevant only insofar as they contain objects manifesting causal powers. Here, speaking of relations between discrete events is just shorthand for speaking of the specific objects that are manifesting causal powers and thereby causing the effects in question, so that statements about types of events, general regularities, or laws of nature are made true by particular objects manifesting causal powers. More precisely, the framework assumes the following: (a) There are causal powers. (b) Some causal powers are irreducible and intrinsic properties of objects. (c) An object can have a causal power even when that power is not manifesting. (d) Having a causal power enables an object to make something happen. 664 M. BRENT (e) When an object is manifesting a causal power it is causing an effect, a process that depends on the causal power and the condition in which it is manifesting. (f ) The manifesting of causal power can be distinct from any effect thereby produced. Several points are worth emphasizing. The manifesting of causal power is not a matter of what would happen if particular conditions were to obtain. Rather, by manifesting its causal powers an object is causing an effect in the actual circumstances at hand. That is, it is the individual persisting object that, by manifesting the relevant causal powers, is producing the effect in question.22 The causing of the effect is a continuous process that depends on the causal powers involved and the conditions in which they are manifesting. To clarify this framework, consider how it would account for a classic example of causation. Suppose that a cue ball is moving across a billiard table and collides with a nearby eight ball, which was until that instant at rest, and the eight ball accelerates towards the corner pocket and drops in while the cue ball slows to a stop. When the moving cue ball comes into contact with the stationary eight ball, this initiates the simultaneous reciprocal manifesting of the relevant causal powers possessed by each ball. The reciprocal manifesting is the change in momentum of each ball upon impact. This ongoing manifesting of causal power, however brief, is causing an effect, the eight ball dropping into the corner pocket as the cue ball rolls to a stop. The process by which each ball undergoes a change of momentum is the continuous and reciprocal manifesting of causal powers possessed by each, and this ongoing manifesting of causal power is causing the relevant effect, the resulting change in momentum and position of each ball.23 Thus, we have a cause, an effect, and a causing: the cause is the moving cue ball coming into contact with the stationary eight ball, the effect produced is the change in momentum and position of each ball, and this effect is brought about as the result of a causing, namely, the continuous and reciprocal manifesting of causal powers possessed by the cue ball and the eight ball as they are interacting, however briefly. Contrast this with the account provided by the commonly held view of causation as an asymmetrical, nonreflexive, and transitive relation among discrete events that presupposes a general regularity or law of nature. The event of the moving cue ball's colliding with the stationary eight ball is followed by the event of the eight ball's accelerating in a particular direction and the cue ball's slowing down while changing direction. Crucially, since this notion of causation presupposes a general regularity or law of nature relating events of this type, the regularity or law of nature is what renders this particular sequence of discrete events an instance of causation. It is only insofar as these events are instances of a general regularity or law of nature that the relation between them is genuinely causal: the momentum of the particular cue ball and eight ball play no role in CANADIAN JOURNAL OF PHILOSOPHY 665 making this relation an instance of causation. That is, the individual objects are not producing these effects: they are causing no result of any kind.24 The point of this contrast is to emphasize an important advantage that the framework of causal powers has over the common conception of the metaphysics of causation. The framework illuminates the sense in which by manifesting causal powers particular persisting objects are causing the effects in question, and that when an object is manifesting causal powers that object is causing the effect in question. In such cases, the events themselves are relevant only insofar as they contain objects manifesting causal powers. Speaking of relations between discrete events is merely shorthand for speaking of the specific objects that are manifesting causal powers and thereby causing the effects in question.25 Of course, many further qualifications would be required to fully defend this framework. Here, the point is to highlight the alternative conception of causation that this framework supports, where causation is a continuous process in which the simultaneous manifesting of reciprocal causal powers possessed by distinct objects produces an effect, where the effect is the outcome of the process in which the manifesting causal powers are interacting. In the case of the cue ball striking the eight ball, the ongoing manifesting of each object's reciprocal causal power is a process resulting in the change in momentum and position of each billiard ball. Here, we have a cause, an effect, and a causing, the continuous and reciprocal manifesting of causal powers possessed by the respective objects. In the next section, I apply this conception of causation to the case of agents and the actions that they perform, and show how it provides an alternative solution to the problem of action. 5. A nonreductive solution to the problem of action Thus far, I have argued that even if the problem of deviant causation was solved, typical reductive solutions nevertheless fail to provide a satisfactory response to the problem of the absent agent, for they do not properly account for your causal role when you are initiating, sustaining, and controlling the movements of your body during an action. In addition, I claimed that the source of this failure is the account of causation that typical solutions assume to be correct, where causation is a relation among discrete events. Because such solutions assume that your role in producing your bodily movements during an action is a causal relation between events, they fail to explain how it is that you are making your body move when acting. In place of such solutions, I suggest that you are making your body move during an action by doing something. In particular, you are making your body move by exerting effort. When you are exerting effort, you are manifesting a causal power that you possess and which is essential to each action that you perform. Your exertion of effort is causally efficacious in at least three related ways. When you begin performing any action from a fixed position, setting your body in motion requires that you exert effort so as 666 M. BRENT to overcome the effects of those physical forces that are affecting your body at all times, thereby making the relevant parts of your body move throughout the space nearby. Once in motion, your ongoing exerting of effort sustains that movement until the action is complete, sometimes while persevering through pain or exhaustion. Moreover, by varying the degree to which you are exerting effort you are controlling the ways that your body is moving, changing its direction and pace as needed. For instance, consider how you might lift and hold a heavy object in the air for several minutes, without lowering your hands and arms or the object. Maintaining that position for several minutes requires that you maintain the degree to which you are exerting effort in the process of contracting your muscles while keeping the heavy object fixed in place. If you continue doing so for some time, as your muscles become weary you must counteract the looming physical exhaustion and remain steady. Crucially, you do not achieve this result by desiring, believing, intending, or in any sense thinking about how to maintain the position of your hands and arms or the heavy object. No doubt, your bodily movements might accord with the content of the relevant desires, beliefs, intentions, and other mental states, and it might be motivationally effective for you to desire, believe, intend, or otherwise think about keeping your hands, arms, and the heavy object in place. However, you do not physically endure in doing so through the causal efficacy of your desires, beliefs, intentions, or other mental events.26 Rather, it is by continuously exerting effort that you are maintaining the position of your body as you persist in holding the heavy object off the ground. That is, you succeed in keeping that object in place by consistently maintaining, and if necessary increasing, the degree of effort that you are exerting while holding the heavy object in the air. In general, when you are exerting effort as you are moving your body your action is an effect of what you are doing, and your exertion of effort is attributed to you, the agent that is acting, rather than to your mental events. Thus, your exertion of effort while moving your body is an instance of agent causation.27 How might the alternative conception of causation outlined above illuminate this notion of agent causation? As a physical object, you possess a number of properties and parts, stand in various relations to other objects, undergo change without annihilation, and persist through time while occupying space. Your exerting effort is the manifesting of a causal power that you possess as an individual persisting object, and the causal power that you are manifesting when exerting effort is not a cognitive capacity of any kind.28 When you are exerting effort your doing so occurs simultaneously with the manifesting of reciprocal causal powers that together produce an effect. In the case of overt bodily action, the reciprocal causal powers are the relevant bodily capacities the manifesting of which consists in the bodily movements at issue, and the effect thereby produced is the action that you are performing. Through your exertion of effort in conjunction with the concurrent movements of your body, you are causing the action in question to occur as an effect of what you are doing. So CANADIAN JOURNAL OF PHILOSOPHY 667 long as the relevant conditions remain unchanged, your ongoing exertion of effort together with the movement of your body is a continuous manifesting of causal powers that are causing the resulting action. Hence, we have a cause, an effect, and a causing. Insofar as your causal powers are properties that you possess as a physical object, you are the cause; the effect is the action that results from your exertion of effort together with the bodily movements in question; and together, your exertion of effort and the movements of your body are causing the action that results from this process. Given this conception of causation, the sense in which you, the agent, are playing an irreducible causal role during your performance of an action just is the sense in which any physical object is playing an irreducible causal role in bringing about the effects that it produces: by manifesting the relevant causal powers that you possess as such an object, you are causing the effect in question. Once we have recognized the irreducible causal role that you are playing when making your body move during an action, a new solution to the problem of action readily presents itself. I suggest that the fundamental difference between the bodily movements that you are making happen during an action and those movements that are merely happening is that the former are occurring in conjunction with your exertion of effort, whereas the latter are not. Although the bodily movements you are making happen during an action and those that are merely happening might seem to be instances of the same type, they are not. The causal contribution of your exertion of effort differentiates those movements that you are making happen while acting from those that are merely happening, marking the movements as categorically distinct. There are a number of features of this solution that are worth highlighting. To begin, the solution presented here rules out the sort of deviant causation in which the relevant events are distinct, where another event intervenes in the sequence that causes the correct bodily action, though in a deviant manner. By contrast, on the framework of causal powers the required distinction between events is gone. For on this framework, your exerting effort occurs simultaneously with the movements of your body in such a way that precludes the interference of another event in the process causing the relevant bodily action. Here, mistakes in performance are possible, but errors of that kind are not instances of deviant causation, as in such conditions the requisite action fails to occur. Thus, although the solution to the problem of action presented here does not assume that exerting effort necessarily succeeds in causing the requisite action, it does rule out cases of deviant causation in which an intervening event interferes in the process causing the relevant bodily action to take place.29 In addition, when you are exerting effort while moving your body during an action, your doing so is not caused by your performance of a prior action. That is, there is no other action that you perform as a means of causing your exertion of effort while moving your body during an action, and so your doing so is causally basic.30 Though your doing so is causally basic, it does not follow 668 M. BRENT that it is uncaused. The alternative solution to the problem of action presented here is compatible with the claim that nothing causes your exertion of effort while you are moving your body during an action, and with the claim that your doing so is causally determined by prior events, conditions, or circumstances. Furthermore, your exertion of effort while moving your body during an action is not itself an action. Your action is the completed effect of the process by which you are causing its occurrence. For instance, in cases of relatively simple actions like raising your arm, your exertion of effort occurs at the same time as the movement in question, as the simultaneous manifesting of reciprocal causal powers that are causing that action. In such cases you are initiating, sustaining, and controlling the movement of your arm by exerting effort, however briefly, and once your arm has risen and you are no longer in the midst of raising it, you have successfully performed a completed action. Thus, your exertion of effort is a feature of the process, however brief, by which you are causing the action in question, but it is not itself an action. 6. Conclusion If what has been said here is correct, we now have a new solution to the problem of action, one in which the notion of agent causation plays an ineliminable role. As we have seen, the problem of action is that of accounting for the difference between those movements of your body that are merely happening and those that you are making happen while acting, and the typical reductive solutions explain the causation of your bodily movement in terms of the occurrence of the relevant mental events, rather than in terms of what you are doing. I have argued that, even if proponents of such solutions solved the problem of deviant causation, they nevertheless fail to provide a satisfactory response to the problem of the absent agent, for they do not properly account for how it is that you are initiating, sustaining, and controlling the movements of your body during an action. So long as such solutions assume that your bodily movement is caused by the relevant mental events, it follows that you are not doing anything when making your body move, you are not causing the action that you perform, and so there is, arguably, no action in view here at all. In addition, I have claimed that the source of this failure is the account of causation that typical solutions assume to be correct, where causation is a relation among discrete events. Because such solutions assume that your bodily movement is caused by the relevant mental events, they fail to explain how it is that you, a particular persisting physical object, are making your body move when acting. In place of such reductive solutions, I argued that, once we have equipped ourselves with a plausible alternative conception of causation, a new solution easily presents itself. According to that solution, the key difference between those movements of your body that are merely happening and those that you are making happen while acting is the fact that when you are moving CANADIAN JOURNAL OF PHILOSOPHY 669 your body during an action, you are making your body move by doing something. In particular, I suggest that you are making your body move by exerting effort. As the simultaneous manifesting of reciprocal causal powers that you possess, when you are exerting effort while moving your body you are causing the action that results from this process, and you are doing so in a way that is absent from situations in which similar bodily movements are merely happening. Thus, the notion of agent causation is crucial to solving the problem of action while explaining how it is that you are making your body move when causing those actions that you perform. Notes 1. For an early and influential statement of the problem, see Frankfurt (1978). In what follows, the topic will be intentional bodily actions that involve overt bodily movements. 2. The term 'event' will be interpreted broadly to include, for instance, mental states, properties, and processes. 3. Historically, this has been the case among defenders of agent causation, but it is not a necessary feature of the view. See, for example, Alvarez and Hyman (1998), Markosian (1999), Mayr (2011), Nelkin (2011), and Franklin (2016). 4. In claiming that you are identical with a particular persisting physical object the idea is that you are a spatiotemporally continuous living human body rather than an event, state, property, process, or other type of entity. The question of whether your mental states, events, properties, processes, etc., are non-physical is not at issue. Here, what matters is that you are identical with the particular spatiotemporally continuous living human body whose movements you are causing when acting. 5. See Bishop (1989), Brand (1984), Bratman (1987), Davidson (1963), Enç (2003), Goldman (1970), and Mele (1992), among many others. 6. See, for instance, Chisholm (1964) and Peacocke (1979). 7. Davidson (1973) raised a very similar example. 8. For the claim that no solution is currently deemed correct, see Aguilar (2012), O'Brien (2012), and Paul (2011). For recent attempted solutions, see Arpaly and Schroeder (2015), Shepherd (2014), and Schlosser (2007). Each is reductive in the sense at issue here and subject to the same objections raised in the main text. 9. See Alvarez and Hyman (1998), Hornsby (2004), Melden (1961), and Pereboom (2014). 10. Velleman (1992, 461, original emphasis). 11. Hornsby (2004, 8 and 13, emphasis added). 12. Velleman (1992, 479). 13. Bratman (2001). 14. See Velleman (1992, 467, n. 16), where he claims that 'an agent, as a persisting entity, is the wrong sort of thing to cause particular events' and that 'the causation of events by the right sorts of things – that is, by other events – may in some cases amount to, or deserve to be described as, their being caused by the agent himself.' See also Velleman (1992, 476), where he says of the relevant mental event that it 'will be what plays the functional role of the agent and is therefore functionally identical to him [or her]' (italics added), where functional roles are causal roles. 670 M. BRENT As I argue in Section 4, causation need not be assumed to be a relation among discrete events, so we need not assume that causation by an agent must be reduced to causation by an agent's mental events. 15. Philosophers who discuss notions of effort that differ from that introduced here include Bradford (2015), Holton (2009), Kane (1996), and Shepherd (2016). Otherwise, it is largely absent from explicit consideration. 16. In fact, a parallel account can be given of the causal role of your exertion of effort when performing mental actions. In such cases, the effort exerted will be distinctly mental, borne out by the relevant cognitive capacities that are used when performing such an action. 17. For volitionalist theories of action see Hornsby (1980), McCann (1974), and O'Shaughnessy (1973). 18. See, for example, O'Shaughnessy (1973, 374). 19. For an account of action that is consistent with this claim, see Sehon (2005, 2016). I briefly discuss such causal independence again in Section 5. 20. For defense of similar frameworks, see Bird (2007), Ellis (2001), Harré and Madden (1975), Heil (2012), Martin (2008), Molnar (2003), and Mumford and Anjum (2011). 21. This notion of causation traces back at least to Hume (1739/1975). Lewis (1973) and Davidson (1967) more recently defended a similar notion. For useful criticism, see Chakravartty (2005), and the texts cited in the previous note. 22. For an argument that particular objects (or substances) cause the relevant effect, see Lowe (2013), Mayr (2011), and Steward (2012). For the claim that only causal powers are relevant, see Buckareff (2011) and Mumford and Anjum (2011). 23. See Huemer and Kovitz (2003) for discussion of a related example. 24. For discussion of a similar point, see Ellis (2001, chap. 1 and 3). 25. See Mumford and Anjum (2011, chap. 1) who defend a similar claim about the role of events in causation. 26. Again, for an account of action that is consistent with the claim that your mental events are causally independent of your exerting effort and the actions that you perform, see Sehon (2005, 2016). 27. A popular account of acting for a reason (e.g. Davidson [1963]) holds that the reason for which you act causes that action to take place. If that were the case, the notion of agent causation introduced here might be taken to rule out the possibility that you can act for reasons. For such a worry, see Rice (2011) and Schlosser (2008). However, there are other plausible accounts of reasons for action, and what it is to act for a reason, that do not assume that reasons for action are mental events or that the reason for which you act causes that action to take place. For the former see Alvarez (2010, 2016), Dancy (2000), and Setiya (2014), and for the latter see Barry (2007), Chan (1995), and Korsgaard (2008, chap. 7). 28. Recall note 17 and the relevant text to which it is appended. In the case of bodily actions exerting effort is not a mental event or mental action, and it is unlike volition, willing, or trying, as such notions are often understood. A parallel account can be given of the causal role of your exertion of effort when performing mental actions, where the effort exerted will be distinctly mental, borne out by the cognitive capacities that are used when performing such an action. 29. Note that although the framework of causal powers eliminates the possibility of this kind of deviant causation, it does not thereby solve the problem of deviant causation. Instead, through rejecting the framework in which causation is a relation among discrete events, it rejects the conditions that give rise to this version of the problem. I thank an anonymous referee for calling my attention to this point. CANADIAN JOURNAL OF PHILOSOPHY 671 30. For recent defense of a notion of basic activity that exploits a similar thought, see Hornsby (2013). Acknowledgements For very helpful discussion of and feedback on earlier versions of this paper, I'm grateful to Avery Archer, Akeel Bilgrami, Jeffrey M. Brown, Michael Brownstein, Andrei A. Buckareff, Ruth Groff, John Heil, Brian H. Kim, Alex Madva, Myrto Mylopoulos, Marco J. Nathan, Lillian O'Brien, Naomi Reshotko, Carol Rovane, Markus Schlosser, Joshua Shepherd, Daniel Telech, Markos Valaris, Anubav Vasudevan, Ben Wolfson, the anonymous referees for this journal, and the audience at The First-Person Perspective in Agency Workshop at University College, Dublin. Notes on contributor Michael Brent is an Assistant Professor of Philosophy at the University of Denver. His current research focuses on metaphysical issues that arise at the intersection of philosophy of action and mind, including the notions of agent causation, effort, self-control, strength of will, and mental action. He is co-organizing an international conference on mental action and the metaphysics of mind, an area of research that he believes ripe with potential. References Aguilar, J. H. 2012. "Basic Causal Deviance, Action Repertoires, and Reliability." Philosophical 22 (1): 1–19. Alvarez, M. 2010. Kinds of Reasons. New York: OUP. Alvarez, M. 2016. "Reasons for Action, Acting for Reasons, and Rationality." Synthese. doi: 10.1007/s11229-015-1005-9. Alvarez, M., and J. Hyman. 1998. "Agents and their Actions." Philosophy 73 (2): 219–245. Arpaly, N., and T. Schroeder. 2015. "A Causal Theory of Acting for Reasons." American Philosophical Quarterly 54 (2): 103–114. Barry, M. 2007. "Realism, Rational Action, and the Humean Theory of Motivation." Ethical Theory and Moral Practice 10 (3): 231–242. Bird, A. 2007. Nature's Metaphysics. New York: OUP. Bishop, J. 1989. Natural Agency: An Essay on the Causal Theory of Action. New York: CUP. Bradford, G. 2015. Achievement. New York: OUP. Brand, M. 1984. Intending and Acting: Toward a Naturalized Action Theory. Cambridge: The MIT Press. Bratman, M. E. 1987. Intentions, Plans and Practical Reason. Cambridge: Harvard University Press. Bratman, M. E. 2001. "Two Problems About Human Agency." Proceedings of the Aristotelian Society 101 (1): 309–326. Buckareff, A. A. 2011. "How Does Agent-Causal Power Work?" The Modern Schoolman 88 (1): 105–121. Chakravartty, A. 2005. "Causal Realism: Events and Processes." Erkenntnis 63 (1): 7–31. Chan, D. K. 1995. "Non-intentional Actions." American Philosophical Quarterly 32 (2): 139–151. 672 M. BRENT Chisholm, R. 1964. "The Descriptive Element in the Concept of Action." The Journal of Philosophy 61 (20): 613–625. Dancy, J. 2000. Practical Reality. New York: OUP. Davidson, D. 1963. "Actions, Reasons, and Causes." The Journal of Philosophy 60 (23): 685–700. Davidson, D. 1967. "Causal Relations." The Journal of Philosophy 64 (21): 691–703. Davidson, D. 1973. "Freedom to Act." In Essays on Freedom of Action, edited by Ted Honderich. 137–156. London: Routledge & Kegan Paul. Enç, B. 2003. How We Act: Causes, Reasons, and Intentions. New York: OUP. Ellis, B. 2001. Scientific Essentialism. New York: CUP. Frankfurt, H. G. 1978. "The Problem of Action." American Philosophical Quarterly 15 (2): 157–162. Franklin, C. E. 2016. "If Anyone Should Be an Agent-Causalist, then Everyone Should Be an Agent-Causalist." Mind 125 (500): 1101–1131. Goldman, A. 1970. A Theory of Human Action. Englewood Cliffs: Prentice Hall. Harré, R., and E. H. Madden. 1975. Causal Powers: A Theory of Natural Necessity. Oxford: Blackwell. Heil, J. 2012. The Universe As We Find It. Oxford: Clarendon. Holton, R. 2009. Willing, Wanting, Waiting. New York: OUP. Hornsby, J. 1980. Actions London: Routledge & Kegan Paul. Hornsby, J. 2004. "Agency and Actions." In Agency and Action, edited by John Hyman and Helen Steward. 1–24. Cambridge: CUP. Hornsby, J. 2013. "Basic Activity." Aristotelian Society Supplementary Volume 87 (1): 1–18. Huemer, M., and B. Kovitz. 2003. "Causation as Simultaneous and Continuous." The Philosophical Quarterly 53 (213): 557–565. Hume, D. 1739/1975. A Treatise of Human Nature. Edited by L.A. Selby-Bigge. Oxford: Clarendon. Kane, R. 1996. The Significance of Free Will. New York: OUP. Korsgaard, C. M. 2008. The Constitution of Agency. New York: OUP. Lewis, D. 1973. "Causation." The Journal of Philosophy 70 (17): 556–567. Lowe, E. J. 2013. "Substance Causation, Powers, and Human Agency." In Mental Causation and Ontology, edited by S. Gibb, E. J. Lowe and R. D. Ingthorsson. 153–172. New York: OUP. Markosian, N. 1999. "A Compatibilist Version of The Theory of Agent Causation." Pacific Philosophical Quarterly 80 (3): 257–277. Martin, C. B. 2008. The Mind in Nature. Oxford: Clarendon. Mayr, E. 2011. Understanding Human Agency. New York: OUP. McCann, H. 1974. "Volition and Basic Action." The Philosophical Review 83 (4): 451–473. Melden, A. I. 1961. Free Action. London: Routledge and Kegan Paul. Mele, A. 1992. Springs of Action. Oxford: OUP. Molnar, G. 2003. Powers: A Study in Metaphysics. Edited by S. Mumford. New York: OUP. Mumford, S., and R. L. Anjum. 2011. Getting Causes from Powers. New York: OUP. Nelkin, D. K. 2011. Making Sense of Freedom and Responsibility. New York: OUP. O'Brien, L. 2012. "Deviance and Causalism." Pacific Philosophical Quarterly 93 (2): 175–196. O'Shaughnessy, B. 1973. "Trying (as the Mental 'Pineal Gland')." The Journal of Philosophy 70 (13): 365–386. Peacocke, C. 1979. "Deviant Causal Chains." Midwest Studies in Philosophy 4 (1): 123–155. Paul, S. K. 2011. "Deviant Formal Causation." Journal of Ethics & Social Philosophy 5 (3): 1–23. Pereboom, D. 2014. "The Disappearing Agent Objection to Event-causal Libertarianism." Philosophical Studies 169 (1): 59–69. CANADIAN JOURNAL OF PHILOSOPHY 673 Rice, R. L. H. 2011. "Agent Causation and Acting for Reasons." American Philosophical Quarterly 48 (4): 333–346. Schlosser, M. E. 2007. "Basic Deviance Reconsidered." Analysis 67 (3): 186–194. Schlosser, M. E. 2008. "Agent-causation and Agential Control." Philosophical Explorations 11 (1): 3–21. Sehon, S. R. 2005. Teleological Realism: Mind, Agency, and Explanation. Cambridge: The MIT Press. Sehon, S. R. 2016. Free Will and Action Explanation. New York: OUP. Shepherd, J. 2014. "The Contours of Control." Philosophical Studies 170 (3): 395–411. Shepherd, J. 2016. "Conscious Action/zombie Action." Noûs 50 (2): 419–444. Setiya, K. 2014. "What is a Reason to Act?" Philosophical Studies 167 (2): 221–235. Steward, H. 2012. A Metaphysics for Freedom. New York: OUP. Velleman, J. D. 1992. "What Happens When Someone Acts?" Mind 101 (403): 461–481.