Hume and the Metaphysics of Agency Joshua M. Wood Journal of the History of Philosophy, Volume 52, Number 1, January 2014, pp. 87-112 (Article) Published by The Johns Hopkins University Press For additional information about this article Access provided by Amherst College (29 Jan 2014 10:04 GMT) http://muse.jhu.edu/journals/hph/summary/v052/52.1.wood.html Hume and the Metaphysics of Agency J o s H u A M . W o o d * Was it not Matter of every Day's Experience, the moving of the Hand by a meer Volition, would be as strange a Thing as an Apparition. -Robert Bragge (1725)1 1 . i n t r o d u c t i o n my topic is hume's construal of the metaphysics of human agency. I take this to be distinct from, and ultimately to underlie, his discussions of free will and moral psychology. Therefore my concern in this paper, as I shall more often refer to it, is Hume's "construal of the basic structure of human agency." This construal includes two claims. The first holds that volition occurs independently of action. The second holds that, no matter how we look at it, the causal mechanism presumed to be operative in voluntary action remains incomprehensible. These two claims play a crucial role in a separate feature of Hume's treatment of human agency. This is his "analysis of human agency," or his assessment of what the basic structure of human agency means for our understanding of causation generally. of particular interest is his argument that, given the truth of the above two claims, we cannot draw the concept of causal power from a consideration of voluntary action. It is unfortunate that the details of Hume's construal and analysis of human agency are neglected in the secondary literature. Not only are his remarks about human agency philosophically interesting, but they are deeply engaged with perspectives on agency in the seventeenth and eighteenth centuries. It has been said that Hume's construal of human agency is "curious," "philosophically confused," and "defective."2 The suggestion is that Hume's construal of * Joshua M. Wood is Visiting Lecturer in Philosophy at Amherst College. Journal of the History of Philosophy, vol. 52, no. 1 (2014) 87–112 [87] 1 Bragge, A Brief Essay concerning the Soul of Man, 23. 2 Respectively: Connolly, "The Will as Impression," 299; Keutner, "The Will as Wish," 306; and stalley, "The Will in Hume's Treatise," 53. Moreover, Baldwin, in "objectivity, Causality, and Agency," 88 journal of the history of philosophy 52:1 January 2014 the basic structure of human agency is simply untenable. At least one commentator, R. F. stalley, takes this view to reveal a problem that "goes to the heart of his whole system," since, presumably, it is uniquely entailed by Hume's empiricism.3 In this paper I argue that Hume's construal of human agency is neither evidently implausible nor indicative of a flaw in his empiricism. I begin (section 2) by presenting Hume's growing concern to articulate his reasons for denying that reflection on voluntary action is the source of our understanding of causation generally. I appeal (section 3) to Hume's analysis of interactions among external objects in order to clarify and distinguish the two arguments that are most important for his analysis of human agency. These are his "separability" and "incomprehensibility" arguments. I then offer (section 4) a general explanation as to how Hume takes these arguments to corroborate his view that the concept of causal power is not derivable from human agency. Here my aim is to explain the philosophical burdens that emerge within the context of voluntary action and that are unevenly distributed between these two arguments. This will enable me to offer careful examinations of Hume's separability (section 5) and incomprehensibility (section 6) arguments. In these examinations I draw from views of human agency in the seventeenth and eighteenth century in order to demonstrate the philosophical merit and general acceptance of the construal of human agency advanced by Hume. 2 . t h e r e l e v a n t t e x t s The amount of space Hume devotes to his analysis of human agency changes considerably over time.4 In Book 1 of the Treatise (published in 1739) he rarely mentions human agency as a possible origin of the concept of causal power. This work is devoted almost exclusively to arguing that this concept cannot be drawn from a consideration of interactions among external objects. The Abstract (March of 1740) contains a few sentences on the potential relevance of human agency to our general understanding of causation. And the Appendix (october of the same year) offers a full paragraph. However, in the Enquiry (1748) we find a discussion that spans three and a half pages. Hume, it seems, takes an increasing interest in making explicit his reasons for rejecting human agency as a potential source of the concept of causal power.5 In the Treatise Hume takes for granted that what he has to say about interactions among external objects carries over to the issue of voluntary action. The latter involves inward experience in the form of impressions of reflection. And suggests that "the account [Hume] offers of agency is not tenable" (114); Hornsby, in "Agency and Alienation," that this account is "strange" (180); and Mumford and Anjum, in Getting Causes from Powers, that it is "implausible" (204). 3 stalley, "The Will in Hume's Treatise," 52. 4 A similar chronology is found in Russell, Freedom and Moral Sentiment, 25–28. The dates I provide here are the same as those provided in Norton and Norton's detailed account of the genesis of the Treatise, Abstract, and Appendix in A Treatise of Human Nature, Vol. 2: Editorial Material, 433–94. 5 several scholars have noted the difference between the Treatise and subsequent work by Hume on the topic of human agency in the Abstract, Appendix, and Enquiry. see Russell, Freedom and Moral Sentiment, 26–28; Blackburn, "Hume and Thick Connexions," 112n14; and Millican, "Against the 'New Hume,'" 249n24. 89hume's metaphys i cs o f ag en cy our experience of external objects is had outwardly in the form of impressions of sensation. Accordingly, Hume, in opening the Treatise's discussion of causation, sets the issue of human agency aside in the following way: "[T]ho' the ideas of cause and effect be deriv'd from the impressions of reflection as well as from those of sensation, yet for brevity's sake, I commonly mention only the latter as the origin of these ideas" (T 1.3.2.16; sBN 78).6 But, Hume adds, "I desire that whatever I say of them may also extend to the former" (T 1.3.2.16; sBN 78). After this point in the Treatise we encounter only a few oblique references to human agency in connection with causal power.7 When Hume touches on human agency in the Abstract, he reminds us of the parallel he takes to hold between his analysis of external objects and his analysis of human agency: We have confined ourselves in this whole reasoning to the relation of cause and effect, as discovered in the motions and operations of matter. But the same reasoning extends to the operations of the mind. (T A25; sBN 655) The relevant operations are, as Hume states, "the influence of the will in moving our body, or in governing our thought" (T A25; sBN 655). It is in the Abstract and Appendix that Hume begins to develop his analysis of human agency. However, it is not until the Enquiry that his analysis of human agency takes its most satisfactory form. Hume begins his treatment of causation in the Enquiry with a fairly concise argument for the claim that "external objects, as they appear to the senses, give us no idea of power or necessary connexion" (EHU 7.9; sBN 64). Then he enters into a lively and disproportionately long discussion of whether the concept of causal power is, as some of his contemporaries maintain, "an idea of reflection" stemming from a consideration of "the command which is exercised by will, both over the organs of the body and faculties of the soul" (EHU 7.9; sBN 64).8 What distinguishes his account in the Enquiry from his remarks in the Abstract and 6 Hume's works are cited in the body of the text in the following way. Citation of A Treatise of Human Nature (including the Appendix) is indicated by 'T ' and includes book, chapter, section, and paragraph numbers from the 2011 Norton and Norton edition followed by the corresponding page number, set off by 'sBN,' from the 1978 selby-Bigge edition revised by Nidditch. Hume's "An Abstract of a Book Lately Published" is cited in a similar fashion but the letter 'A' is appended to the paragraph number from the 2011 Norton and Norton edition of the Treatise. Citation of An Enquiry concerning Human Understanding is indicated by 'EHU ' and includes the section and paragraph numbers from the 2000 Beauchamp edition followed by the corresponding page number, set off by 'sBN,' from the 1975 selby-Bigge edition revised by Nidditch. 7 I take his references to human agency to be implicit in his occasional remarks about spirit or inner experience. He states, most notably, that an experience of causal power is not discoverable among "the objects, which are presented to our senses, [nor those] which we are internally conscious of in our own minds" (T 1.3.14.10; sBN 160; my emphasis). We also find the following claims: that "no impression, either of sensation or reflection, implies any force of efficacy" (T 1.3.14.10; sBN 160; my emphasis); that a "single instance [of power]" is discoverable "neither in body nor spirit, neither in superior nor inferior natures" (T 1.3.14.10; sBN 160; my emphasis); and "The uniting principle among our internal perceptions is as unintelligible as that among external objects" (T 1.3.14.29; sBN 169; my emphasis). 8 I wish to delay discussion of whether Hume's analysis of human agency is successful against thinkers who take it to be the case that voluntary action is the relevant origin of the concept of causal power. Locke and Berkeley are the two thinkers most often associated with this thesis. I submit that an adequate discussion of this issue is beyond the scope of the present paper. 90 journal of the history of philosophy 52:1 January 2014 Appendix is not simply its length. We find in the Enquiry something like a justification for that feature of Hume's construal of human agency that philosophers have recently come to regard as highly controversial. This is Hume's claim that volition and action are separable. 3 . h u m e ' s a n a l y s i s o f e x t e r n a l o b j e c t s It will be helpful for our understanding of Hume's analysis of human agency if we start with an overview of his analysis of interactions among external objects. It is primarily on the basis of his separability9 and incomprehensibility arguments that Hume denies that the concept of causal power can be drawn from any objects or objective relations presumed to exist in the world. Both arguments are designed to establish the conclusion that there is no necessary connection between two objects or events. What distinguishes these arguments is the way in which they reach this conclusion. Hume's separability argument relies on the claim that an object can be conceived independently of another object. Hume's incomprehensibility argument, by contrast, relies on the claim that the causal mechanism presumed to be operative in a given interaction is unintelligible or incomprehensible. Here I want to explain why Hume takes it to be the case that if either of these claims holds true for any given interaction between objects, then this interaction is incapable of serving as the origin of the concept of causal power. 3.1. The Separability Argument Hume's separability argument is intended to weaken the view that consideration of external objects could possibly yield the concept of causal power. And Hume intends to weaken this view by demonstrating that causal power is not even implicated in interactions among them. For, presumably, we cannot draw this concept from an object that does not actually possess causal power. The separability argument assumes that the a priori relation of inseparability in thought serves as a criterion of objective causal relations between items in the world. According to this view, if two objects are separable in thought, then it follows that there is no objective causal relation between them. Hume offers us an example of the collision of two billiard balls. When we see one billiard ball moving toward another, we typically expect that the motion of the first billiard ball will be communicated to the second. But in cases like this we can conceive a clear and consistent idea of one body's moving upon another, and of its rest immediately upon the contact; or of its returning back in the same line, in which it came; or of its annihilation; or circular or elliptical motion: And in short, of an infinite number of other changes, which we may suppose it to undergo. (T 1.3.9.10; sBN 111)10 9 What I refer to as Hume's 'separability argument' also goes by the name of the 'no necessary connection argument.' see Nadler, "The Medieval Roots of the occasionalist Roots of Hume." 10 Compare Hume's observation in the Enquiry: "[M]ay I not conceive, that a hundred different events might as well follow from that cause? May not both these balls remain at absolute rest? May not the first ball return in a straight line, or leap off from the second in any line or direction? All these suppositions are consistent and conceivable" (EHU 4.10; sBN 29–30). 91hume's metaphys i cs o f ag en cy According to the present assumption, if a necessary connection held objectively between the impulse of the first billiard ball and motion in the second, then we would not be able to conceive of alternative scenarios such as these. But since we can conceive these effects, we are committed to denying that causal power is metaphysically implicated in this interaction. If this holds for all interactions among external objects, as Hume thinks it does, then we cannot possibly draw the concept of causal power from a consideration of external objects. The assumption underlying Hume's separability argument is evident in the work of Nicolas Malebranche, who takes causal power to be operative only in those cases where two objects cannot be separated in thought. Malebranche writes in his Search after Truth (1674–75), "A true cause as I understand it is one such that the mind perceives a [logically] necessary connection between it and its effect."11 However, Malebranche is not alone in assuming as much. John sergeant, in his Method to Science (1696), says of causal relations that they involve "Natures being connected Naturally and, so Connected that it is Impossible it should be otherwise."12 But he also takes what holds metaphysically of such relations to be mirrored in certain inferences conducted by the understanding: [A] Cause and a Reason do onely differ in this, that the word [Cause] speaks the thing as it is in Nature, and [Reason] the same thing as 'tis in our understanding; and Proper Causes and Effects in Nature are necessarily connected to one another, and, consequently, do Infer one another naturally.13 Hume takes it to be the case that inseparability in thought, as a criterion of the reality of causal power, fails to discover any causal relations existing among external objects. This result would not have concerned Malebranche, since he himself reached this conclusion. Malebranche claims, for example, that "when a ball that is moved collides with and moves another, it communicates to it nothing of its own, for it does not itself have the force it communicates to it."14 By contrast, that causation is not metaphysically implicated in interactions among external objects would have been an alarming consequence for a philosopher like sergeant. 3.2. The Incomprehensibility Argument Hume's incomprehensibility argument poses a slightly different challenge. It does not aim to deny the existence of an objective causal relation by conceiving one object or event independently of another. Rather it is designed to establish the impossibility that empirical investigation or metaphysical insight discovers a relation capable of licensing an a priori inference. This is the conclusion, as Hume expresses it, that "the inference we draw from cause to effect, is not deriv'd . . . from such a penetration into their essences as may discover the dependance of 11 Malebranche, Search, 450. With respect to this interpolation, see Nadler ("The Medieval Roots of the occasionalist Roots of Hume," 454), who maintains that "Malebranche categorically identifies a causally necessary relation with a logically necessary one." I share this reading of Malebranche. However, for an opposing view of Malebranche see Kail, "Hume, Malebranche and 'Rationalism.'" 12 sergeant, Method to Science, 277. 13 sergeant, Method to Science, 276; second and third brackets in original. 14 Malebranche, Search, 448. 92 journal of the history of philosophy 52:1 January 2014 the one upon the other" (T 1.3.6.1; sBN 86). Hume offers the example of fire in the Enquiry: "We know, that, in fact, heat is a constant attendant of flame; but what is the connexion between them, we have no room so much as to conjecture or imagine" (EHU 7.8; sBN 64). Though the separability argument may be fundamental to Hume's analysis of external objects, the incomprehensibility arguments speaks directly to those who assume that they are acquainted with the causal power operative in a given interaction or who at least take acquaintance of this sort to be possible. Hence we find Hume claiming that experience "never gives us any insight into the internal structure or operating principle of objects" (T 1.3.14.29; sBN 169); and that "we can never penetrate so far into the essence and construction of bodies, as to perceive the principle, on which their mutual influence depends" (T 2.3.1.4; sBN 400). so I take the central claim of the incomprehensibility argument to be summed up by Hume's denial that we can "conceive any connexion betwixt [two objects], or comprehend distinctly that power or efficacy, by which they are united" (T 1.3.14.13; sBN 161). Conceiving as much, Hume states, would "amount to a demonstration, and wou'd imply the absolute impossibility for the one object not to follow, or be conceiv'd not to follow upon the other" (T 1.3.14.13; sBN 161–62). Note that if a purportedly objective relationship is incomprehensible, then it follows that there is nothing discoverable in the objects themselves that might serve to ground an a priori connection between them. And if neither empirical investigation nor metaphysical insight reveals a connection that is capable of licensing a deductive inference, as Hume thinks is the case for all interactions among external objects, then these methods of inquiry cannot possibly trace the concept of causal power to a consideration of objects. If I am right about the distinction between Hume's separability and incomprehensibility arguments, then he can employ these arguments independently of one another. I think this explains one of Hume's criticisms of Malebranche in the Enquiry. Malebranche holds that our concept of causal power stems from a consideration of the divine will. This claim is based on his view that the requisite a priori connection holds only with respect to the relation between God's will and an effect. As Malebranche writes, "[T]here is such a connection between His will and the motion of all bodies, that it is impossible to conceive that He wills a body to be moved and that this body not be moved."15 Yet Hume offers the following criticism: We are ignorant, it is true, of the manner in which bodies operate on each other: Their force or energy is entirely incomprehensible: But are we not equally ignorant of the manner or force by which a mind, even the supreme mind, operates either on itself or on body? Whence, I beseech you, do we acquire any idea of it? (EHU 7.25; sBN 72)16 15 Malebranche, Search, 448; also: "[W]e see only His volitions to have an absolutely necessary and indispensable connection with natural effects" (684). 16 The present criticism expresses a concern that runs throughout Hume's texts. In the Treatise Hume poses the following problem for drawing the concept of causal power from a consideration of God's will: "'[T]is . . . impossible to discover or even imagine any such active principle in the deity" (T 1.3.14.10; sBN 160). In the Abstract Hume revisits the same problem: "What idea have we of energy or 93hume's metaphys i cs o f ag en cy This criticism does not take the form of conceiving a divine volition occurring independently of some effect. Rather Hume directs our attention to the incomprehensibility of the causal power Malebranche takes to be implicated in the operation of God's will. If this relationship is incomprehensible, then how could it serve to render causation as such intelligible? This is also Hume's attempt to turn a particular line of argument, one that Malebranche himself advances, against the foundation of occasionalism. one reason Malebranche denies the existence of objective causal relations among material objects is because they are "incomprehensible."17 As he explains, There are many reasons preventing me from attributing to secondary or natural causes a force, a power, an efficacy to produce anything. But the principal one is that this opinion does not even seem conceivable to me. Whatever effort I make in order to understand it, I cannot find in me any idea representing to me what might be the force or the power [some philosophers] attribute to creatures.18 Malebranche tells a different story about the divine will. He reports that "whatever effort of mind I make, I can find force, efficacy, or power only in the will of the infinitely perfect Being."19 However, the suggestion from Hume is that Malebranche is unable tell us any more about the causal power he takes to be implicated in divine volition than other philosophers are able to tell us about the causal power they take to be implicated in interactions among external objects. And this seems to be true. We find Malebranche making claims about divine volition that fail to explain the nature of the relationship between God's will and events in the world. We are told, of course, that the "motor force" implicated in interactions among external objects "is nothing other than the will of God."20 But about the power in question Malebranche can tell us little more than that: "His power is His will, and to communicate His power is to communicate the efficacy of His will."21 The incomprehensibility argument that Hume brings against Malebranche is designed to highlight the assumption that is implicit in any attempt to derive the concept of causal power from a consideration of the divine will. The relevant assumption is that the power of God's will is sufficiently comprehensible to serve as the origin of our understanding of causation generally. But this assumption is false. Hume concludes his criticism of Malebranche by pointing out that, with respect to both interactions among external objects and the implementation of God's will, "We surely comprehend as little the operations of one as of the other" (EHU 7.25; sBN 73). Given the terms of Hume's incomprehensibility argument, it follows that a consideration of the divine will cannot possibly serve as the origin of the concept of causal power. power even in the supreme Being?" (T A26; sBN 656). And, finally, in a footnote in the Appendix Hume speaks of an "imperfection that attends our ideas of the deity," namely, an inability to "form a distinct idea of the force and energy of the supreme being" (T 1.3.14.12n30; sBN 633n1). 17 Malebranche, Search, 669. 18 Malebranche, Search, 658. 19 Malebranche, Search, 658. 20 Malebranche, Search, 448. 21 Malebranche, Search, 450. 94 journal of the history of philosophy 52:1 January 2014 4 . h u m e ' s a n a l y s i s o f h u m a n a g e n c y Having distinguished Hume's separability and incomprehensibility arguments above, we are now in a better position to appreciate the contours of his analysis of human agency. It is on the basis of this analysis that Hume writes, We may . . . conclude . . . without any temerity, though with assurance; that our idea of power is not copied from any sentiment or consciousness of power within ourselves, when we give rise to animal motion, or apply our limbs to their proper use and office. (EHU 7.15; sBN 67) Hume believes the same result holds for voluntary thought. on the way to this conclusion Hume identifies two basic components of human agency. These are volition and action. Apart from their disparate origins in sensation and reflection, Hume, generally speaking, does not take there to be a significant difference between the experience of interactions among external objects and the experience of voluntary action in ourselves. He lists "motives, volitions and actions" alongside properties of external objects such as "figure and motion" as candidates for constant conjunction (T 2.3.1.17; sBN 406–7). This means that, according to Hume, volition and action enter into purportedly causal relationships in the same way as interactions among external objects. The essential ingredients in both cases, at least insofar as Hume's account of causal judgment is concerned, are constant conjunction and the customary association that develops on the basis of repeated experience. Hence Hume's analysis of human agency, turning away from a consideration of objects in the world, brings the same arguments to bear on the relationship between volition and action in us. The success of Hume's separability argument in the case of human agency depends on the plausibility of either experiencing or conceiving volition apart from action. And the success of his incomprehensibility argument rests on the impossibility of either discovering or distinctly conceiving the causal relation presumed to hold between volition and action. Note that Hume, in constructing his incomprehensibility argument, has done well to put his opponent in the position of needing to prove that we can distinctly conceive how the will works. Hume clearly has the upper hand here. But the separability argument does not have the same advantage built into it. In this case, Hume has put himself in the position of needing to prove that it is possible to conceive volition occurring independently of action. Therefore implicit in Hume's separability argument is the burden of lending some measure of plausibility to this controversial feature of his construal of human agency. Here I want to focus on the status of this explanatory burden within the development of Hume's analysis of human agency. When Hume begins his analysis of human agency in the Abstract he does not provide an example in which the separability of volition and action is plainly possible. Rather he asserts, "When we consider our will or volition a priori, abstracting from experience, we are never able to infer any effect from it" (T A26; sBN 656). This claim presupposes that it is possible to conceive, or meaningfully "consider," an instance of volition apart from a corresponding action. Hume, generally speaking, takes this to be possible for "All those objects, of which we call the one cause and the other effect," since he holds that these objects, "consider'd in themselves, 95hume's metaphys i cs o f ag en cy are . . . distinct and separate from each other" (T 2.3.1.16; sBN 405). Hume, as we have seen, has an explanation as to why we should take it to be true that separability in thought holds for interactions among external objects. What Hume needs is an explanation as to why we should take this to hold in the case of human agency. In the Abstract we only find the assumption that volition and action are separable in this way. When Hume writes about the separability of volition and action in the Appendix he does not bring this assumption to light. He claims that, in the case of human agency, "The effect is there distinguishable and separable from the cause" (T 1.3.14.12; sBN 632). And, rather than investigate this key assumption, Hume introduces in the Appendix a description that is congenial to the presumed separability of volition and action. Hume distinguishes between "the will being consider'd here as a cause" and its "effects," namely, "[t]he motions of our body, and the thoughts and sentiments of our mind" (T 1.3.14.12; sBN 632). This explicit characterization of voluntary action as a relation between the distinct events of willing and acting recurs several times in the course of the Enquiry. Hume states of voluntary action generally that "[a]n act of volition produces motion in our limbs, or raises a new idea in our imagination" (EHU 7.9; sBN 64). He writes of bodily movements in particular that "[t]he motion of our body follows upon the command of our will" (EHU 7.10; sBN 65); and, in the case of thought, that "[w]e only feel the event, namely, the existence of an idea, consequent to the command of the will" (EHU 7.17; sBN 68). However, this is not all we find in the Enquiry. one of the most interesting passages in this text provides an example in which Hume thinks we can speak meaningfully of volition in the absence of action. This is Hume's example of volition in the case of abrupt paralysis: A man, suddenly struck with a palsy in the leg or arm, or who had newly lost those members, frequently endeavours, at first, to move them, and employ them in their usual offices. Here he is as much conscious of power to command such limbs, as a man in perfect health is conscious of power to actuate any member which remains in its natural state and condition. (EHU 7.13; sBN 66) Hume does not offer this example for the explicit purpose of buttressing the central claim of his separability argument, but I think it captures his attitude toward the separability of volition and action. As I hope to show, this passage does not provide merely incidental support for Hume's construal of human agency. Rather this passage implicitly demonstrates the plausibility that Hume takes to hold for the claim that volition and action are separable.22 5 . t h e s e p a r a b i l i t y o f v o l i t i o n a n d a c t i o n Hume's separability argument has met with two criticisms. stalley suggests that the paralysis example is "clearly fictitious" and that Hume's motive in construct22 My reading of this passage is stronger than the reading given by Pitson in Hume's Philosophy of the Self. He writes, "This . . . case, incidentally, might be used to justify the claim that there are such things as volition, as distinct from bodily movements, though Hume himself appears simply to take the existence of volitions for granted" (133–34). 96 journal of the history of philosophy 52:1 January 2014 ing this example is "theoretical rather than empirical." 23 The implication is that Hume's paralysis example is implausible and at best theoretically convenient. so I take stalley to express the criticism that is most often brought against Hume's construal of human agency. This is the straightforward denial that Hume can speak meaningfully of an instance of willing in isolation from a corresponding act.24 Furthermore, Thomas Keutner suggests that wishing "is the model for [Hume's] account of willing."25 The implication, in this case, is that the success of Hume's separability argument depends on a fundamental misunderstanding of the will. something has clearly gone wrong within Hume's construal of human agency if he holds that willing the movement of an arm is indistinguishable from wishing that a certain arm movement would occur. I respond to stalley's criticism and others like it by drawing attention to the polemical context of Hume's paralysis example as well as the historical precedent for examples of this kind. I believe this background will enable us to see more clearly the plausibility that Hume and others attribute to such cases. I respond to Keutner by offering what I think is a more persuasive reading of the passage that is essential for his criticism. 5.1. Hume's Criticism of Colliber and Mayne one reason to think that Hume's paralysis example is more than theoretically convenient is that this example bears directly on a peculiar position advanced in the eighteenth century. It was maintained by at least two of Hume's contemporaries that we can attribute causal power to the will on introspective grounds alone. The internal evidence of the will's power, according to this view, is available to us prior to acting and even without our ever having undertaken action. As it seems to me, Hume's foremost concern in presenting the paralysis example is to argue against this particular version of the claim that introspection serves as a basis for attributing causal power to the will. The paralytic in this example, as Hume writes, "is as much conscious of power to command such limbs, as a man in perfect health is conscious of power to actuate any member which remains in its natural state and condition" (EHU 7.13; sBN 66). Lest we take ourselves to be mistaken in judging volition to be indistinguishable in these cases, Hume posits that "consciousness never deceives" (EHU 7.13; sBN 66). I do not take Hume to deny that there is some experience that might be referred to, perhaps misleadingly, as a "consciousness of power." What I 23 stalley, "The Will in Hume's Treatise," 48. 24 There are at least two versions of this particular criticism in the literature on Hume. Those who offer this criticism along Rylean lines deny either that we have any experience of willing or that we have an experience of willing such as Hume describes which might then be separated from action: Aune, Reason and Action, 50; Bricke, "Hume's Volitions," 86; stalley, "The Will in Hume's Treatise," 48–51; Bricke, Mind and Morality, 53; and Mumford and Anjum, Getting Causes from Powers, 204. Those who offer this criticism along Anscombean lines deny that human agency can be meaningfully conceived in terms of the distinct events of willing and acting: Anscombe and Geach, Three Philosophers, 107; Connolly, "The Will as Impression," 276–77; stalley, "The Will in Hume's Treatise," 48–52; Baldwin, "objectivity, Causality, and Agency," 114; and Mumford and Anjum, Getting Causes from Powers, 204–7. It will take considerable work to mitigate the force of these arguments. My concern in this paper is simply to establish that there is some merit to Hume's claim that volition and action are separable. 25 Keutner, "The Will as Wish," 307. 97hume's metaphys i cs o f ag en cy take Hume to deny is that this experience confirms that the will is metaphysically endowed with causal power. If this experience did constitute a direct "consciousness of power" in the will, then, presumably, it would arise only in cases in which the will is causally effective. But this "consciousness of power," which fails to discriminate between cases of effective and ineffective operations of the will, does not reliably track causal influence. "Consequently," according to Hume, "neither in the one case nor in the other, are we ever conscious of any power" (EHU 7.13; sBN 66). The result of Hume's paralysis example is that this "consciousness of power," which does not constitute a legitimate acquaintance with causal power in the will, cannot possibly serve as a basis for the metaphysical claim that the will is endowed with causal power. That introspection is helpful in this matter was suggested by samuel Colliber, who writes in his An Impartial Enquiry (1718), I think I may appeal to any Considering Man whether he be not, in All ordinary Cases, sensible of an Ability of darting his Thoughts upon Any Particular object evn' Antecedently to any deliberation.26 Colliber takes the will to be inherently endowed with causal power, and he takes this to be something of which "we are Conscious."27 The same position is put forth in somewhat stronger terms by Charles Mayne in his Two Dissertations (1728). Mayne holds that "the Mind, before ever it exerts its Will or Power of Chusing, knows and is Conscious to it self, that it hath a Power of Choice and Preference."28 He acknowledges that this claim-"to know I have a Power of acting, before ever I have acted, or had any Tryal or Experience of it"-is "very strange and wonderful."29 However, he does not offer much in its defense.30 The account from Mayne readily lends itself to the particulars of Hume's paralysis example. Mayne claims,"'Tis utterly impossible . . . that self-consciousness should be deceived or imposed on."31 Hume grants that this is true. Mayne also holds, remarkably, that "to lose a Power, without being sensible of the Loss . . . manifestly implies, that there never was any Consciousness or inward sense and Knowledge, either of the Power or the act."32 Hume, I believe, grants the truth of this claim as well. so, in order to defeat Mayne's position, all Hume needs to show 26 Colliber, An Impartial Enquiry, 43. 27 Colliber, An Impartial Enquiry, 43. 28 Mayne, Two Dissertations, 156–57. 29 Mayne, Two Dissertations, 208. 30 Mayne's defense amounts to this: "That the Mind, before ever it exerts its Will or Power of chusing, is conscious, and knows within itself, that it hath a Power of Choice and Preference [is] a necessary Condition of its Willing at all: Insomuch that, the very first time I had occasion to exert my Will, or make use of my Elective Power, I could not possibly exercise it, or do any voluntary Act, without knowing and being conscious to my self [before-hand] that I have such a Faculty or Power in my self" (Two Dissertations, 208; former brackets are my own). Mayne assumes that when we act voluntarily we exercise causal power. He then argues that we must know that we possess causal power on independent grounds because otherwise we could not come to exercise this power in voluntary action. However, Mayne does not consider the possibility that voluntary action is compatible with ignorance of this power or perhaps compatible with the absence of causal power in the will. 31 Mayne, Two Dissertations, 177. 32 Mayne, Two Dissertations, 201–2. 98 journal of the history of philosophy 52:1 January 2014 is that it is possible to be insensible to the loss of the will's capacity for influence. And this is precisely what Hume intends his paralysis example to demonstrate. We learn that it is possible to have a "consciousness of power" even in a case in which volition is not accompanied by the intended movement. In light of Hume's counterexample, the inner experience to which Mayne appeals is unable to confirm the existence of causal power in the will.33 of course, neither Colliber nor Mayne advance the philosophically ambitious claim that our concept of causal power is drawn from a consideration of the will. Nevertheless their singular defense of the basic claim that the will is endowed with causal power might suggest that it is possible to draw this concept from human agency. And, to remove this possibility, Hume argues for the intermediate conclusion that we lack purely introspective grounds for attributing causal power to the will. Yet, we might ask, is there any reason to think that Hume was familiar with the writings of Colliber and Mayne? I am not certain that he was. However, I find it is interesting that Edmund Law's 1731 edition of William King's Origin of Evil, a work with which Hume was likely familiar, cites both of these thinkers, suggests that they hold similar views on this specific topic, and provides excerpts from each of them in which they explicitly claim that causal power is directly introspectible in the will.34 5.2. Historical Precedent for Hume's Paralysis Example Another reason to think that Hume's paralysis example is more than a convenient fiction is the historical precedent on which it capitalizes. There is more than one way in which Hume's contention that volition and action are separable can be 33 Craig, in "The Idea of Necessary Connexion," offers what is, in my opinion, a puzzling reading of Hume's paralysis example. Craig argues that the relevant concern of this example is an "epistemological one" (220). And to get this result Craig takes it upon himself to deny all of the following: (i) that Hume is concerned with the "formation of the idea of power" on the basis of a consideration of human agency; (ii) that Hume intends to address the "immediate contents of consciousness," specifically as this concerns a direct consciousness of the will; (iii) that our reading of this passage should heed Hume's "professed intentions"; and (iv) that Hume "realize[s] what he is up to" (220). Perhaps a full appreciation of Hume's paralysis example requires us to spell out an epistemological concern with, as Craig puts it, "how we know or come to believe truths about causes" (217). However, I do not think this point hinges on denying all of the above. Moreover, the polemical context that I have provided for Hume's paralysis example would seem to make such a sweeping denial unadvisable. 34 The full title of Mayne's work is Two Dissertations concerning Sense, and the Imagination with an Essay on Consciousness. Mayne's discussion of the inherent and introspectible power of the will is restricted to his Essay on Consciousness. Hence Law, in his edition of King's Origin of Evil, refers to Mayne in explanatory note 65 as "the Author of the Essay on Consciousness" (164). Here Law provides an excerpt from Mayne in which the relevant thesis is stated twice. (The passage is from Two Dissertations, 208.) Law himself introduces this excerpt from Mayne by claiming that we have no need of "an Experiment to assure us that we really have such a Power [in the will]," since, as he explains, "we are sufficiently conscious of it before any such trial" (164). Immediately after this excerpt Law, in lieu of quoting Mayne directly, reports that "The Author proceeds to shew, that this Fore-consciousness of a power of willing or choosing does most clearly demonstrate that the Mind in all its Volitions begins the Motion, or acteth from itself" (165). (This claim is lifted with slight abbreviation from Two Dissertations, 209.) Furthermore, in explanatory note 82, Law, referring to samuel Colliber as "S. C.," provides an excerpt from Colliber's Impartial Enquiry in which the relevant thesis is stated once. (The passage is from Impartial Enquiry, 42–43.) Finally, explanatory note 82 includes a footnote in which Law cites Colliber's text, "Impartial Enquiry, &c. p. 42, 43," and then adds, "see also an Essay on Consciousness, p. 205, &c" (213). 99hume's metaphys i cs o f ag en cy traced to extant views about human agency in the seventeenth and eighteenth centuries. However, I will limit myself to a certain kind of precedent, namely, examples involving paralysis or injury that are similar to Hume's own example. To begin, descartes writes in his Description of the Human Body (1664), We can . . . observe that when some part of our body is harmed, for example when a nerve is irritated, the result is that the part in question ceases to obey our will as it normally does.35 What is interesting about this observation is the conclusion descartes draws from it. descartes holds that "without the requisite disposition of the organs" an action cannot be produced "no matter how much we may will this to happen."36 The Ethics (1675) of Arnold Geulincx contains an example that, in several respects, is remarkably close to the one Hume uses in the Enquiry: suppose . . . someone has retired to bed in the evening in the best of health. during the night, as he sleeps, a catarrh affects a nerve of his arm, which is thereby rendered paralysed. When he wakes up in the morning, not knowing what has happened, he immediately sets about getting dressed, and wants, as usual to pick up his shirt; but . . . his hand . . . lies limply on the bed. . . . This paralytic quite clearly feels, and is conscious that, when he wanted to pick up his shirt he was doing the same as at other times when he would indeed pick up his shirt.37 As Geulincx notes elsewhere, the point is that the person in this example devotes himself to [an act] insofar as is, for his part, sufficient for motion to be made, and devotes all that he was wont to devote to it at other times, when upon his willing it motion was granted to his hand.38 Locke states in a letter to Philippus van Limborch (1708), I readily recognize ineffective volition, as when a paralytic wills to move his palsied hand; I grant that that volition is ineffective and without result, but not that it is 'incomplete.' For the act of willing is in this case just as complete as it was formerly when the hand complied with the volition.39 And Andrew Baxter remarks in his Enquiry into the Nature of the Human Soul (1733), [I]f the muscle, or muscles, designed to be the instruments in moving any joint, be cut transversly, or any other way disabled from their function, the will may command with all imaginable intenseness, yet will no motion of the joint ensue.40 What Baxter takes this to demonstrate is that "all on the part of the will [may be exerted] as at other times" when a healthy limb or joint responds normally.41 Each of these examples is intended to offer a case in which an instance of willing is unaccompanied by an act. For they each specify an instance in which volition in the event of paralysis or injury is either more apparent than in ordinary cases 35 descartes, The Philosophical Writings of Descartes, 315. 36 descartes, The Philosophical Writings of Descartes, 315. 37 Geulincx, Ethics, 229 Annotation 13. 38 Geulincx, Ethics, 231 Annotation 16. 39 Locke, Correspondence, VII.404. This letter was published in 1708 as part of a collection entitled Some Familiar Letters between Mr Locke and his Friends. 40 Baxter, Enquiry into the Nature of the Human Soul, 69. 41 Baxter, Enquiry into the Nature of the Human Soul, 69. 100 journal of the history of philosophy 52:1 January 2014 of voluntary action or just as apparent as in ordinary cases. Nevertheless we might wonder whether these examples stem from a tacit Cartesian assumption about how the mind relates to the body.42 If this assumption prevents someone from seeing the implausibility of volition occurring in the absence of an act, then the influence of this assumption might explain why various thinkers, including Hume, take such cases seriously. so it is worth noting that similar examples are to be found among thinkers who are either writing prior to descartes or take themselves to be influenced by Aristotle. For example, in his Physiologia (1567), Jean Fernel, a respected physician of the sixteenth century, writes [W]hen paralysis takes over the limbs, the nerves are deprived then of spirit and faculty, so that not even the most effective voluntas [or will] can bring about movement.43 And Kenelm digby, an Aristotelian natural philosopher and biologist, states in his Two Treatises (1644), [W]hen we are in health, our armes, and legges, and all our limbes, obey our will, reaching what we command them, and carrying us whither we desire . . . but if our sinewes be [altered]; well we may wish and strive, but all in vaine: for we shall not be able to make them performe their due functions.44 It seems to me that examples of this kind can be taken to have philosophical significance independently of whether a thinker subscribes to a Cartesian view of the relationship between mind and body. I do not want to suggest that all claims about the separability of volition and action in this period are carefully thought out. There are several instances in which the separability of volition and action is either assumed or merely asserted.45 It is important to emphasize that Hume, unlike the members of this group, does not avail himself of the bare assertion that volition is possible in the event of paralysis. Rather what we find in Hume is an example that is carefully designed to illustrate 42 Hornsby, in "Agency and Alienation," suggests that Hume's "strange claims" about human agency might be explained by the fact that "Hume follows descartes in separating mind from brain" (177). 43 Fernel, Physiologia, 493; quoted with slight alteration. 44 digby, Two Treatises, 392–93. Admittedly, this gloss on digby is somewhat controversial, since, prior to writing the Two Treatises, he developed a personal relationship with descartes and was familiar with the Discourse on Method (1637). 45 For example, the assumption of separability can be found in William Wollaston, The Religion of Nature Delineated, 185; and Joseph Butler, The Analogy of Religion, 32. Malebranche is an interesting case. If Malebranche has an argument for the separability of volition and action, then it is not one that resembles Hume's paralysis example. However, my view is contrary to the thesis, advanced by some commentators, that Malebranche plays a significant role in the development of Hume's thought about the separability of volition and action. For example, McCracken, who takes Malebranche to be the relevant inspiration for Hume's paralysis example, states in Malebranche and British Philosophy that "[b]oth thinkers remark that a paralytic may will that his arm rise but that the effect is not thereby produced" (260). This view is also found in Kail, Projection and Realism in Hume's Philosophy, 60; and Kail, "Hume, Malebranche and 'Rationalism,'" 321. But Malebranche, so far as I can tell, never appeals to paralysis in an attempt to establish the separability of volition and action. Another commentator, Jolley, explains Malebranche's position in "Berkeley and Malebranche on Causality" as follows: "[I]t is not logically necessary that my arm should go up when I will to raise it; it is conceivable that I should be suddenly afflicted with paralysis" (229). As much as an example like this is both compatible with and supportive of the claim that volition and action are separable, I think it is misleading to suggest that Malebranche himself draws on paralysis for the purposes of justifying this claim. 101hume's metaphys i cs o f ag en cy a case in which volition is uncoupled from action. Hume's example concerns an abrupt onset of paralysis. And he asks us to think about what someone ignorant of this change would experience in the initial attempt to move her limb. This example is meant to tease out the intuition that we can speak meaningfully of someone willing to move a paralyzed limb in just the same way as when, a moment earlier, she successfully moved it.46 It does not seem implausible to claim that someone in such circumstances could have an experience of volition. I submit, in contrast to the view advanced by many commentators, that we lack sufficient reason to think that the separability of volition and action advocated by Hume is either obviously problematic or uniquely entailed by his empiricism. There is at least some merit to the claim itself. And Hume, as it seems to me, is not driven strictly by prior theoretical concerns to endorse this claim. Indeed, as we have seen, this claim is found in the work of several thinkers who do not share the tenets of Hume's empiricism. Furthermore, it is because of the care with which Hume constructs his paralysis example that I believe he intends this to do the implicit work of justifying his construal of human agency in terms of the distinct events of willing and acting.47 5.3. Separability and the "Secret Wish" Near the beginning of Hume's analysis of human agency in the Enquiry we find the following claim: Were we empowered, by a secret wish, to remove mountains, or controul the planets in their orbit; this extensive authority would not be more extraordinary, nor more beyond our comprehension. (EHU 7.11; sBN 65) This passage serves as the basis of Keutner's contention that, according to Hume, "volition is nothing but a wish."48 He then attributes to Hume a failure to see the "epistemic difference between willing and wishing."49 Presumably, it is this misunderstanding of the basic structure of human agency that leads Hume to claim that volition and action are separable. Hume, on this reading, mistakenly concludes from the fact that we can clearly conceive a wish in isolation from action that volition itself is separable from action. However, I find Keutner's interpretation of 46 Hume's paralysis example is considerably more helpful in establishing this intuition than his earlier offhand remark in the Treatise : "A person, that has lost a leg or an arm by amputation, endeavours for a long time afterwards to serve himself with them" (T 1.3.9.18; sBN 117). 47 The success of Hume's separability argument in its most comprehensive form depends on the possibility of conceiving volition existing apart from both bodily motion and thought. However, the latter is a possibility for which Hume does not explicitly argue. Malebranche had described mental agency in the Search after Truth in a way that is favorable to this task: "We know through inner sensation that we will to think about something, that we make an effort to do so, and that at the moment of our desire and effort, the idea of that thing is presented to our mind" (671). As we have seen, a similar description is found in the Enquiry: "We only feel the event, namely, the existence of an idea, consequent to the command of the will" (EHU 7.17; sBN 68). Though Hume offers no suggestion as to how we might conceive volition apart from thought, this need not pose a significant problem for the comprehensiveness of his separability argument. Hume can appeal to the fact that we sometimes will to think of a word or the image of an object and yet fail to produce it; see schmidt, David Hume, 204n8. 48 Keutner, "The Will as Wish," 307. 49 Keutner, "The Will as Wish," 308. 102 journal of the history of philosophy 52:1 January 2014 this passage to be highly doubtful. Hume neither models his concept of volition on wishing nor is there, lurking in this passage, an implicit failure to distinguish between wishing and willing. Hume's remark about wishing is an unmistakable allusion to Joseph Glanvill. In his Vanity of Dogmatizing (1661), Glanvill writes that the causal relation involved in human agency "will be as hard to apprehend, as that an empty wish should remove Mountains."50 Hume was evidently taken with this analogy. And Hume, like his predecessor, is using this analogy to make a similar point about the incomprehensibility of the causal mechanism presumed to be operative in voluntary action. The relation between our will and ordinary voluntary acts is just as obscure to us as the relation between our will and events on which it clearly has no bearing. However, to fill out our reading of this passage we must take note of Hume's additional suggestion that there is no a priori connection between volition and action. Hume observes that if it was the case that our will did move mountains or "controul the planets in their orbit," then this would not be "extraordinary." The reason, according to Hume, is that there is nothing about the will as such that entails its operation be restricted to our limbs and thoughts. Hume, then, would agree with the sentiment of another predecessor, Jeremiah seed, who writes the following in his Discourses (1745): [T]he soul has no more a Power, independently of it's [sic] Maker, to move it's [sic] Limbs by a mere Thought; than it has a Power to move the sun, Moon, and stars by merely willing it: And He, who has made the former consequent upon our Volition, might have made the latter so too by his Almighty Power.51 Hume may not be alluding to this passage when he speaks of the possibility of influencing the "planets in their orbit." But the remark from seed is helpful for the following reason. Hume would accept the suggestion that it just so happens that volition is ordinarily accompanied by the motion of our limbs and the alteration of our thoughts. And Hume does not need to conflate wishing and willing to reach this conclusion. seed, who takes it that God has established the familiar relationship between our will and certain events, expresses the same view when he suggests that there is nothing about the will itself that prevents God from widening its scope of influence. According to Hume, if things were otherwise and we happened to discover in the course of life that our will "controulled the planets in their orbit," then our attitude toward the basic structure of human agency would not be appreciably different. so far as Hume and seed are concerned, it is a merely contingent fact about the will that its operation is not conjoined with celestial events of this kind. 50 Glanvill, The Vanity of Dogmatizing, 22. Popkin considers whether Glanvill's work may have had an impact on Hume in "Joseph Glanvill: Precursor of david Hume." He observes, "There are only a few scraps of evidence of any direct influence" (303). However, Popkin neglects to list the present passage among them. 51 seed, Discourses, 150–51. 103hume's metaphys i cs o f ag en cy 6 . t h e i n c o m p r e h e n s i b i l i t y o f v o l u n t a r y a c t i o n There are nine instances of Hume's incomprehensibility argument in the Appendix and Enquiry.52 I believe Hume makes extensive use of this argument because he takes it to be effective as well as fairly uncontroversial. But commentators have identified what seem to be two problematic claims in Hume's incomprehensibility argument. Edward Craig takes this argument to employ a "gratuitously strong condition" for the possibility of discovering power in voluntary action.53 If Craig's reading of this argument is correct, then, as I explain below, Hume is forced to embrace a conclusion about human agency he should want to avoid. Michael Ayers, objecting to a distinct premise, takes this argument to depend on "what might be called an extreme Lockean scepticism."54 If Ayers is right, then Hume's claim about the incomprehensibility of voluntary action can be traced to an unduly skeptical view of what can be known about human agency. However, the former objection depends on a misunderstanding of Hume's argument. And the latter objection, as I hope to show, stems from a neglect of the historical context of Hume's denial that we can comprehend the mechanics of voluntary action. Here too consideration of the relevant philosophical background will help us to appreciate the plausibility of Hume's incomprehensibility claim as well as its independence from the tenets of empiricism. 6.1. Human Agency and its Obscurity Hume holds that if causal power were discoverable in voluntary action in such a way that might serve as an origin of this concept, then it would be possible, as he sometimes puts it, to "perceive" or be "fully acquainted with" the causal connection involved (EHU 7.12; sBN 65). Here Hume's concern is with the possibility of foreseeing an effect on the basis of our acquaintance with "any apparent energy or power in the cause, which . . . renders the one an infallible consequence of the other" (EHU 7.10; sBN 64–65).55 But Hume argues that the causal relation presumed to be operative in voluntary action is incomprehensible. According to Hume, [T]he means, by which [voluntary action] is effected; the energy, by which the will performs so extraordinary an operation; of this we are so far from being immediately conscious, that it must for ever escape our most diligent enquiry. (EHu 7.10; sBN 64–65) 52 This may be why some commentators present Hume's analysis of human agency exclusively in terms of this argument. see Kemp smith, The Philosophy of David Hume, 436–38; Ayer, Hume, 63–64; Buckle, Hume's Enlightenment Tract, 195–97; Allison, Custom and Reason in Hume, 184–85; and Bell, "Hume on Causation," 158–60. 53 Craig, "The Idea of Necessary Connexion," 217. 54 Ayers, "Natures and Laws from descartes to Hume," 107. 55 As strawson notes in The Secret Connexion, if "the knowledge of the power by which the mind operates" is to serve as an origin of the concept of causal power, then it "would have to involve a grasp of how it is that the causes produce the effects they do of a sort that would make a priori certain inferences about such matters possible" (194). 104 journal of the history of philosophy 52:1 January 2014 Therefore we cannot hope to derive the concept of causal power from empirical or metaphysical considerations of voluntary action. Hume brings this argument to bear on three distinct features of human agency. The first concerns our general understanding of the relation between the will and voluntary action. Iterations of this type of argument refer to "natures" and "essences." In the case of bodily motion, Hume writes that if by consciousness we perceived any power or energy in the will, we must know this power; we must know its connexion with the effect; we must know the secret union of soul and body, and the nature of both these substances; by which the one is able to operate, in so many instances, upon the other. (EHU 7.11; sBN 65) However, we do not know how the mind and body causally relate to one another. The same holds for how the will relates to thought: "[d]o we pretend to be acquainted with the nature of the human soul and the nature of an idea, or the aptitude of the one to produce the other?" (EHU 7.17; sBN 68).56 The second type of incomprehensibility argument descends to a consideration of the will's scope of influence. For example, we cannot explain why we can move our "tongue and fingers" but not our "heart and liver" (EHU 7.12; sBN 65). According to Hume, if we were "fully acquainted with the power or force, by which [the will] operates," then we "should also know, why its influence reaches precisely to such boundaries, and no farther" (EHU 7.12; sBN 65). We are equally ignorant of the will's scope of influence in the case of mental operations. Hume notes that "our authority over our sentiments and passions is much weaker than that over our ideas," and that "these limits are not known by reason, or any acquaintance with the nature of cause and effect" (EHU 7.18; sBN 68).57 A related mystery is that the will's scope of influence over both bodily motion and mental operation is variable. He remarks that "[a] man in health possesses more of [voluntary control], than one languishing with sickness" and that "[w]e are more master of our thoughts in the morning than in the evening: Fasting, than after a full meal" (EHU 7.19; sBN 68). Hume asks, "Is there not here, either in a spiritual or material substance, or both, some secret mechanism or structure of parts, upon which the effect depends, and which, being entirely unknown to us, renders the power or energy of the will equally unknown and incomprehensible?" (EHU 7.19; sBN 68–69). The third type of incomprehensibility argument is narrower still. It focuses on our ignorance of how the will works even in those instances in which we take its influence to be clear. With respect to voluntary action in the form of thought, Hume observes, We only feel the event, namely, the existence of an idea, consequent to the command of the will: But the manner, in which this operation is performed; the power, by which it is produced; is entirely beyond our comprehension. (EHU 7.17; sBN 68) 56 Hume brought up the same argument in the Appendix: "so far from perceiving the connexion betwixt an act of volition, and a motion of the body; 'tis allow'd that no effect is more inexplicable from the powers and essence of thought and matter. Nor is the empire of the will over our mind more intelligible" (T 1.3.14.12; sBN 632). 57 Here Hume expands on a remark in the Appendix: "We have command over our mind to a certain degree, but beyond that lose all empire over it: And 'tis evidently impossible to fix any precise bounds to our authority, where we consult not experience" (T 1.3.14.12; sBN 632). 105hume's metaphys i cs o f ag en cy And, finally, with regard to our ignorance of how willing to walk relates to the many anatomical changes that ensue when we do walk, Hume asks, Can there be a more certain proof, that the power, by which this whole operation is performed, so far from being directly and fully known by an inward sentiment or consciousness, is, to the last degree, mysterious and unintelligible? (EHU 7.14; sBN 66) When we will to walk we do not simply step forward. Rather we bring about countless minute bodily effects that we neither intend nor realize are taking place, but that together constitute walking. Hume's emphasis on these puzzling aspects of voluntary action is intended to establish a conclusion that is relevant to philosophers. This is the conclusion that neither empirical investigation nor metaphysical insight is capable of "instructing us in the secret connexion," which, in the case of human agency, "binds [volition and action] together, and renders them inseparable" (EHU 7.13; sBN 66). But Hume also intends his incomprehensibility argument to establish a conclusion that is relevant to a broader audience. Here he has in mind the "generality of mankind" who, according to Hume, "suppose [in ordinary instances of causation] that . . . they perceive the very force or energy of the cause, by which it is connected with its effect, and is for ever infallible in its operation" (EHU 7.21; sBN 69). Insofar as this view is held with respect to voluntary action, Hume's incomprehensibility argument makes it readily apparent that it can be little more than an unreflective supposition. Therefore ordinary convictions about human agency are equally incapable of supporting the claim that the concept of causal power is derived from a consideration of voluntary action. 6.2. Intelligibility and the Discovery of Power Hume's incomprehensibility argument relies on an assumption about the conditions of discovering power in voluntary action. There are several passages in which Hume spells out what he takes to be known when we "know a power" or "know its connexion with the effect" in such a way that could possibly constitute an origin of the concept of causal power (EHU 7.11; sBN 65). Hume claims, for example, that we "must know the secret union of soul and body, and the nature of both these substances" (EHU 7.11; sBN 65); "why [the will's] influence reaches precisely to such boundaries, and no farther" (EHU 7.12; sBN 65); and "that very circumstance in the cause, by which it is enabled to produce the effect" (EHU 7.17; sBN 67–68). Therefore it may seem as if Hume makes greater demands on our knowledge than is necessary for the discovery of an impression of power. This has led to Craig's suggestion that Hume "impos[es] a gratuitously strong condition" on the discovery of an impression of power in voluntary action.58 one reason to reject Hume's stated condition, as Craig argues, is that it seems possible to discover an "impression of power" in everyday instances of voluntary action without thereby resolving the metaphysical "puzzle" of agency.59 Hence Craig claims that it is not clear why discovering an impression of power "would necessarily bring all these 58 Craig, "The Idea of Necessary Connexion," 217. 59 Craig, "The Idea of Necessary Connexion," 216. 106 journal of the history of philosophy 52:1 January 2014 [epistemic] benefits with it."60 By an 'impression of power' Craig appears to mean either the familiar experience of exertion or ordinary attributions of causal power to ourselves. Neither is epistemically taxing. The experience of exertion arises without our being acquainted with the metaphysics of agency. And we evidently have grounds for attributing causal power to ourselves independently of whether we have discovered an intelligible connection that inherently binds volition and action. Therefore the problem to which Craig draws attention seems to be this. The condition stipulated within the incomprehensibility argument forces Hume to the undesirable conclusion that we, for lack of understanding the metaphysics of agency, either cannot experience exertion or have no grounds for attributing causal power to ourselves. What I take to be important about this criticism is that it brings out the potential conflict between Hume's construal of human agency and our ordinary view of voluntary action. However, a consequence of this sort arises for Hume only if it is true that his incomprehensibility argument is designed to test for the possibility of discovering an impression of power in either of the above senses. But we would be mistaken to frame his incomprehensibility argument in this way. Hume's incomprehensibility argument is specifically designed to assess the possibility that our understanding of causation as a whole is drawn from a narrow consideration of voluntary action. The strength of his stated condition is appropriate to this task. It permits Hume to argue against the potential relevance of the experience of exertion, which he refers to as "nisus or strong endeavour," on the following basis: This sentiment of an endeavour to overcome resistance has no known connexion with any event: What follows it, we know by experience; but could not know it a priori. (EHU 7.15n13; sBN 67n1) That the experience of exertion fails to ground an a priori inference does not commit Hume to the absurd view that we do not have this experience. But, given the terms of his argument, it does entail that our experience of exertion cannot possibly serve as the origin of the concept of causal power. Moreover, Hume's extensive use of the incomprehensibility argument is not intended to demonstrate that we lack grounds for attributing causal power to ourselves. The constant conjunction between volition and action is, at least according to Hume, sufficient to ground such attributions.61 Whatever may hold for empirical and metaphysical considerations of human agency, if Hume's incomprehensibility argument has some consequence for everyday attributions of causal power to ourselves then I believe it is the following. The success of Hume's incomprehensibility argument entails that it is not possible to trace our general understanding of causation to 60 Craig, "The Idea of Necessary Connexion," 216. 61 In "Natures and Laws from descartes to Hume," Ayers writes the following of Hume's position: "our belief that our thoughts are having an effect on the world, our subjective sense of our own agency, is as much a result of custom and habit as any other causal belief" (107). I think Ayers is right about what Hume's view must be with respect to the development of causal beliefs about voluntary action. But I am less confident about whether Hume is committed to explaining every feature of "our subjective sense of our own agency" in terms of the influence of custom. This complex issue will have to be addressed more fully elsewhere. 107hume's metaphys i cs o f ag en cy voluntary action even despite the ordinary conviction, which Hume readily allows, that "we ourselves . . . are possessed of power" (EHU 7.9; sBN 64). 6.3. Historical Precedents for Hume's Appeal to Incomprehensibility If my presentation of the incomprehensibility argument is correct, then Hume incorporates an epistemic condition that is less problematic than it may seem. But the incomprehensibility argument still relies on what appears to be a remarkably skeptical view of our understanding of voluntary action. What I want to argue here is that, contrary to Ayers's suggestion that this claim stems from "an extreme Lockean scepticism," Hume's appeal to the incomprehensibility of voluntary action does not belie an unduly skeptical view. Ayers's mention of "Lockean scepticism" presumably refers to Locke's claim that we cannot know the inherent nature, or real essence, of things. Locke writes in his Essay (1689): "[H]ow little 'tis of Being, and the things that are, that we are capable to know."62 And Locke takes it to be the case, for example, that we do "not know the real Essence of a Peble, or a Fly, or of our own selves."63 Given Locke's broad epistemic curtailment, perhaps it should not surprise us to find several passages in which he himself claims that the inherent nature of voluntary action is incomprehensible. He remarks that, though the effects of the will are evident, "the manner [of its operation] hardly comes within our comprehension."64 Elsewhere Locke writes, [T]he operation of our Minds upon our Bodies is ... unconceivable. How any thought should produce a motion in Body is as remote from the nature of our Ideas, as how any Body should produce any Thought in the Mind. That it is so, if Experience did not convince us, the Consideration of the Things themselves would never be able, in the least, to discover to us.65 I want to separate Locke's reservations about our knowledge of real essences in general from his specific claim that the metaphysics of human agency is incomprehensible. For, whatever grounds Locke may have for the former, I do not think the latter contention, much less Hume's purportedly "extreme" version of it, is skeptical in nature. This claim was commonplace among thinkers in the seventeenth and eighteenth centuries. More importantly, however, is the fact that many instances of this claim are endorsed independently of skepticism about our understanding of human agency. Apart from Locke, this claim was advanced vehemently by two of Hume's predecessors: Glanvill and Malebranche.66 But the view that the nature of voluntary 62 Locke, Essay, Book IV, Chapter iii, section 29. 63 Locke, Essay, II.xxiii.35. 64 Locke, Essay, II.xxiii.28. 65 Locke, Essay, IV.iii.28; also: "[T]he communication of Motion by Thought, which we attribute to spirit, is as evident, as that by impulse, which we ascribe to Body. Constant Experience makes us sensible of both of these, though our narrow understandings can comprehend neither. For when the Mind would look beyond those original Ideas we have from sensation or Reflection, and penetrate into their Causes, and manner of production, we find still it discovers nothing but its own short-sightedness" (Essay, II.xxiii.28). 66 see Glanvill, The Vanity of Dogmatizing, 21 and 24–26; Malebranche, Search, 449–50 and 669–71. 108 journal of the history of philosophy 52:1 January 2014 action is incomprehensible held true for numerous other thinkers in this period. spinoza writes in his Ethics (1671) that "no one knows how, or by what means, the Mind moves the body."67 This thought also worked its way into some unpublished notes Newton made on Query 31 of the Opticks: "We find in orselves a power of moving our bodies by or thoughts (but the laws of this power we do not know)."68 (Alan Gabbey estimates that these notes were penned in 1705.) Hutcheson writes, in his Inquiry into the Origin of our Ideas of Beauty and Virtue (1726), of the "mystery" that "the Act of Volition should move Flesh and Bones."69 And Joseph Butler writes, in his Analogy of Religion (1740), that "we are greatly in the dark, upon what the Exercise of our living Powers depends."70 one of the more colorful expressions of this claim is from François Fénelon who, in his Demonstration (1713), remarks that an agent "is an absolute stranger to what he has done in all the inward springs of his Machine."71 There are many other instances in which it is claimed, as a matter of course, that the causal relation operative in voluntary action is incomprehensible. It is particularly interesting that this claim was advanced by several thinkers who take the will to be obviously endowed with causal power. Richard Bentley claims, in his Eight Boyle Lectures (1692), that "we cannot conceive the matter of the soul's Action and Passion; nor what Hold it can lay on the Body, when it voluntarily moves it: yet we are as certain, that it doth so, as of any . . . Infallible demonstratio[n]."72 King claims, in his Origin of Evil (1702), that the will is endowed with causal power despite our ignorance of "the Modus" by which it operates."73 We are ignorant, as King writes, of how the Members of the Body can be moved by a Thought of the Mind, and at the direction of the Will. Yet no body denys these things, because he knows not the manner in which they are perform'd.74 Finally, Jean-Pierre Crousaz, in his Art of Thinking (1724), attributes causal power to the will while denying that, in cases of voluntary action, he is in "any way sensible, how or in what manner I my self produce this Motion, or am the Cause of it."75 Hume's incomprehensibility argument is able to capitalize on this particular view of human agency. For Hume does not want to draw the conclusion that we have no basis for claiming that the will is causally effective. Volition, as Hume recognizes, is accompanied by action frequently enough to justify a significantly 67 spinoza, Collected Works, 495. 68 Gabbey supplies this quote from Newton in "Force and Inertia in seventeenth-Century dynamics," 13. 69 Hutcheson, An Inquiry into the Original of our Ideas of Beauty and Virtue, 272. Hutcheson also writes the following in the 1744 edition of his Metaphysicae Synopsis, "[A]lthough we are quite aware that we are doing something in changing our thoughts and desires and appetites, yet all the rest of our human efficacy is uncertain, even in the movement and control of our own bodies" (LMN 91). 70 Butler, The Analogy of Religion, 22. 71 Fénelon, Demonstration, 118. 72 Bentley, Eight Boyle Lectures on Atheism, second Lecture, 31–32. 73 King, Origin of Evil, 190. 74 King, Origin of Evil, 190. 75 Crousaz, A New Treatise of the Art of Thinking, I.142. 109hume's metaphys i cs o f ag en cy attenuated version of the claim that the will is a cause. This explains how, at least on Hume's account of the formation of causal beliefs, it is possible to develop the ordinary conviction that our will is causally effective in voluntary action. But Hume does want to draw the intermediate conclusion that our basis for this conviction stems from neither empirical investigation of the will nor metaphysical insight into its operation. If Hume is right about this, then the conclusion his incomprehensibility argument is ultimately designed to establish follows necessarily. We cannot hope to draw the concept of causal power from an acquaintance with the causal mechanism presumed to be operative in voluntary action. For this mechanism is thoroughly incomprehensible. What I believe we find by surveying the discussion of human agency in the seventeenth and eighteenth centuries is that few thinkers in this period claimed to comprehend the inherent nature of voluntary action. This suggests that the view advanced by Hume and others is not skeptical in nature. Rather it is a view which is not only compatible with the existence of certain ordinarily beliefs about voluntary action, but which accurately reflects the impenetrability of the metaphysics of human agency. 7 . c o n c l u s i o n Hume most likely did not take his claim about the separability of volition and action to be particularly novel. Even less remarkable, from Hume's perspective, would have been his claim that the causal mechanism presumed to be operative in voluntary action is incomprehensible. This, I think, should caution us against a certain reading of Hume's construal of the basic structure of human agency. For example, John Connolly attributes to Hume a "revolutionary view"76 and "a new concept [of will]."77 stalley claims that Hume's view "differs radically from [the views] offered by most of his predecessors and contemporaries."78 As it seems to me, this reading of Hume is historically inaccurate. If there is novelty in Hume's account, I submit that it lies in his explanation of how we develop certain causal beliefs about voluntary action. For it is here that the principles of empiricism begin to shape Hume's treatment of human agency. These principles do not themselves influence his construal of the basic structure of human agency. Furthermore, Hume's claims about separability and incomprehensibility are not as problematic as some scholars take them to be. His claim about separability, as I have argued, neither belies an obvious misunderstanding of the will nor is a claim that is uniquely entailed by his empiricism. Connolly traces the separability claim to Hume's "epistemology and theory of meaning,"79 and stalley to what he refers to as the "constraints of Hume's system."80 The suggestion seems to be that only Hume, given his empiricism, could have been theoretically driven to endorse a claim of this kind. But Hume's claim about the separability of volition and action is not strictly imposed on him by his empiricism. This claim, when regarded on its 76 Connolly, "The Will as Impression," 296. 77 Connolly, "The Will as Impression," 301. 78 stalley, "The Will in Hume's Treatise," 42. 79 Connolly, "The Will as Impression," 294. 80 stalley, "The Will in Hume's Treatise," 49. 110 journal of the history of philosophy 52:1 January 2014 own, appears to have at least some philosophical merit. If this is the case, then this explains how it is that numerous thinkers during this period came to endorse the separability claim independently of adopting the principles of empiricism. A related criticism might be brought against Hume's claim about the incomprehensibility of voluntary action. For this claim might be taken to stem from an unwarranted skepticism about our understanding of human agency. However, once this claim is regarded in the appropriate light, that is, as a claim directed solely at our understanding of the inherent nature of human agency, then it becomes apparent that it holds uncontroversially. And, far from being an outgrowth of skepticism, the incomprehensibility claim was endorsed by thinkers of every stripe. Hume, as it seems to me, integrates into his treatment of human agency two claims about the metaphysics of voluntary action that are both defensible and widely accepted at the time of his writing.81 b i b l i o g r a p h y a n d a b b r e v i a t i o n s Allison, Henry. Custom and Reason in Hume: A Kantian Reading of the First Book of the Treatise. New York: oxford university Press, 2008. [Custom and Reason in Hume] Anscombe, G. E. M., and P. T. Geach. Three Philosophers. Ithaca, NY: Cornell university Press, 1961. Aune, Bruce. Reason and Action. dordrecht: d. Reidel Publishing Company, 1977. Ayer, A. J. Hume: A Very Short Introduction. 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