chapter 4 Spinoza and the Mark of the Mental * Martin Lin A mind, according to Spinoza, is a state of a thinking substance. The essence of a thinking substance is thought. And what is thought? Spinoza is all but silent on this question. To some extent, this silence is appropriate. Spinoza holds that thought is an attribute of substance, which means that it is a fundamental way of conceiving a substance. Because thought is fundamental, it does not admit of metaphysical analysis; there is nothing more fundamental than thought in terms of which such an analysis could be given. As Spinoza puts the point in an early work, the Short Treatise, attributes "need no genus or anything through which they might be better understood or explained: for since they exist as attributes of a self-subsisting being, they too become known through themselves."1 In other words, it is impossible to give a real definition – specify the essence – of an attribute because they are understood through themselves. But even where real definition is impossible, there can be alternative forms of elucidation. That a concept represents something fundamental does not mean that it bears no inferential relations to other concepts. Thus we could be given a mark of the mental. Such a mark would consist of necessary and sufficient conditions that, although falling short of a real definition, nevertheless allow us to draw a line between the mental and the non-mental. The need for such a mark is suggested by Spinoza's dialectical situation. Spinoza makes controversial claims about thought. For example, his claim that thought is fundamental is denied by materialists such as * I would like to thank Michael Della Rocca, Don Garrett, and John Morrison for comments on a draft of this chapter. I am also grateful to audiences at the Department of Philosophy at the University of Manitoba, the Finnish-Hungarian Seminar for Early Modern Philosophy, and the South Central Seminar on Early Modern Philosophy for immensely helpful feedback on the ideas contained in this chapter. 1 KV I 7 | G I 46–47. 82 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 Hobbes. Furthermore, his claim that both thought and extension are attributes of a single substance is rejected by substance dualists like Descartes. Spinoza would claim that both Hobbes and Descartes are misidentifying which phenomena are mental. For example, Hobbes errs when he classifies certain kinds of motions of extension as thoughts and Descartes errs when he classifies certain substances as non-thinking. These disagreements are of a particularly radical sort. When Hobbes claims that thought is a mode of extension, Spinoza regards him as making a kind of conceptual error. When Spinoza says that a single substance is both extended and thinking, Descartes similarly regards Spinoza as making a conceptual error. Although not every philosophically important notion must be defined or otherwise elucidated in order to make progress, it is easier to proceed without such elucidation where there is general agreement about the nature of the subject matter. But the nature of the mental is an area where deep and pervasive disagreement obtains. Adjudicating these disagreements in the absence of a mark of the mental would be difficult, if not impossible. Of course, this dialectical situation does not entail that there is a mark of the mental. It only makes plain that it would be desirable to have one and, consequently, worth our while to look for one. Spinoza never explicitly provides us with a mark of the mental. He simply asserts that the essence of mind is thought and leaves it at that. Likewise he asserts that the essence of body is extension without further clarification. But this leaves open the possibility that such a mark can be recovered from consideration of what Spinoza does say about the mind and the attribute of thought. In what follows, I will consider several candidates for the mark of the mental, either drawn from tradition or suggested by Spinoza's own text. I will argue that although Spinoza's text is certainly suggestive of some of them, on closer examination, each of them is ultimately inconsistent with Spinoza's explicit commitments. Although this result is, in some respects, disappointing, I will further argue that Spinoza's metaphysics of mind and body entails that at most one of them can be characterized explicitly. I will conclude by discussing what this means for Spinoza's philosophy of mind. Characterizing the Mind The mental as the cause of intelligent action. The mental has sometimes been characterized as what explains intelligent action. Such a characterization Spinoza and the Mark of the Mental 83 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 can be extracted from Descartes' Discourse on Method.2 According to Descartes, certain effects provide us with reasons to postulate a mental state rather than a physical state as the cause. For example, if we observe a creature competently using language or appropriately responding to diverse novel situations with a high degree of flexibility, then we have reason to suppose that the cause of its action is mental rather than physical. This is because there is, Descartes appears to presuppose, an explanatory gap between mechanism and intelligent action. We cannot conceive of a machine that could have such flexibility. So, the cause must be nonmechanical, which, Descartes assumes, means that the cause must be mental. This characterization of the mental is unavailable to Spinoza because he denies mind–body interaction. Because intelligent action involves bodily motion, Spinoza cannot allow that it hasmental causes. Why does Spinoza deny mind–body interaction? The reason is that he believes that physical events must be understood through physical causes andmental events must be understood through mental causes. He holds this on the basis of two putative facts: (1) causes and effects must have something in common and (2) there is nothing in common between mind and body. If mind and body interacted, then physical events would be understood through mental events and mental events through physical events. Consequently, Spinoza denies interaction. Spinoza's denial of interaction pushes him to assert that there is no explanatory gap between mechanism and intelligent action. According to him, every intelligent physical action has a purely physical explanation, understood in an objective metaphysical sense. Of course, in many cases we have not discovered these explanations. But this simply reflects the primitive state of our knowledge or perhaps indicates our cognitive limitations. The appearance of an explanatory gap is thus explained by our ignorance. As Spinoza puts it, "We know not yet what the body can do."3 The optimistic "yet" in this formula suggests that Spinoza believes that mechanistic science will eventually uncover such explanations. Although Spinoza is sometimes more cautious about the limits of human knowledge, it is nevertheless clear that he has no doubt that such explanations are possible, at least in principle. The mental as the exemplification of a distinctive causal structure. Perhaps Spinoza's denial of mind–body interaction suggests a different characterization of the mental in causal terms. Consider the claim that something 2 AT VI 56–60 | CSM I 139–141. 3 E3p3s. 84 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 is mental just in case it has causes and effects that are themselves mental. There is no doubt that Spinoza believes this, but as a characterization of the mental it would be viciously circular. If we are seeking to clarify the concept of the mental, then it will not help to be told that the mental is what has mental causes and effects. But causal relations might serve to distinguish the mental from the physical in a different way. The mental and the physical might be distinguished in terms of causal structural properties. Causal structure is what remains when we abstract the causal relations away from those things that they relate. The physical could then be, for example, the realm that exemplifies causal structure S whereas the mental would be the realm that exemplifies a different causal structure S*. A criterion based on different causal structure is suggested by certain interpretations of Descartes according to which the mind has genuine causal powers of its own whereas the body is causally inert and is, at most, only an occasional cause.4 Thus mind and body are distinguished by different causal structural properties. Although it succeeds in avoiding circularity, the causal structure characterization of the mental will not work for Spinoza because of his parallelism doctrine.5 The parallelism consists of three claims: (1) For every mode of extension there is a mode of thought that represents it; (2) for every mode of thought there is a mode of extension represented by it; (3) the order and connection of ideas is the same as the order and connection between things. "Order and connection" includes causal structure. The mental realm and the physical realm are thus identical with respect to causal structure and thus no characterization of the mental for Spinoza can appeal to causal structure. Simplicity as the mark of the mental. Plato, in his Phaedo, famously claims that the soul is simple.6 It does not have parts. This claim of simplicity is widely influential and is held by many subsequent philosophers, including Descartes, who argues in the Meditations for mind–body dualism on the basis of the claim that the mind is simple: The body has parts. The mind does not have parts. Therefore, the mind is distinct from the body.7 Spinoza, however, rejects the simplicity of the mind. Indeed, he denies its simplicity for reasons closely related to the ones we considered in 4 See, e.g., Garber, "HowGod CausesMotion" and "Descartes andOccasionalism," both of which are collected in Garber's Descartes Embodied. I'm grateful to Helen Hattab for bringing to my attention the connection between this putatively Cartesian criterion and the causal structure criterion. 5 E2p7, E2p7d, and E2p7s. 6 Phaedo 78b–79e. 7 AT VII 86/CSM II 98. Spinoza and the Mark of the Mental 85 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 connection with causal structure. For Spinoza, causal structure determines mereological structure. Consider the following text: Definition: When a number of bodies, whether of the same or of different size, are so constrained by other bodies that they lie upon one another, or if they so move, whether with the same degree or different degrees of speed, that they communicate their motions to each other in a certain fixed manner, we shall say that those bodies are united with one another and that they all together compose one body or Individual, which is distinguished from the others by this union of bodies. (Def. after 1p13s) According to this text, part–whole relations are determined by causal relations. It says that for any collection of bodies, these bodies are parts of a whole just in case (1) other bodies force them to move together or (2) if one of them moves, then its motions are communicated to the others according to a stable pattern. These causal relations, forcing and communicating, must have a parallel under the attribute of thought because the order and connection of ideas is the same as the order and connection of bodies. In virtue of these parallel causal relations, Spinoza concludes that: The idea that constitutes the formal being of the humanMind is not simple, but composed of a great many ideas. (2p15) Mereological structure cannot, therefore, serve to distinguish the mind from the body. Consciousness as the mark of the mental. Another popular candidate for the mark of the mental also originates with Descartes: consciousness. When Descartes tries to explain what the various modes of thought (belief, volition, imagination, sensation, etc.) have in common, he says that they are such that we are immediately conscious of them.8 Thus all thoughts are immediately conscious. Moreover, only thoughts are immediately conscious. Although we are aware of bodies, including our own, our consciousness of them is mediated through sensory thoughts. Does Spinoza have an account of consciousness and, if so, what is it and can it serve to distinguish the mind from the body? There is some controversy surrounding these questions. If, as some commentators believe, Spinoza has no theoretically serviceable notion of consciousness, then appealing to the notion in characterizing the mental will be of little 8 Principles I.9, AT VIII-A7, and Second Replies, AT VII 160. 86 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 use and we need not consider the matter further.9 There are commentators, however, who believe that Spinoza does have a theory of consciousness.10 In order to assess this claim and determine whether, if true, it could provide Spinoza with a mark of the mental, we have to look more closely at the issue. The most promising interpretations focus on the following two texts: In proportion as a body is more capable [aptius] than others of doing many things at once, or being acted upon in many ways at once, so its mind is more capable than others of perceiving many things at once. And in proportion as the actions of a body depend more on itself alone, and as other bodies concur with it less in acting, so its mind is more capable of understanding distinctly. (E2p13s) Because human bodies are capable [apta] of a great many things, there is no doubt but that they can be of such a nature that they are related to minds which have a great knowledge of themselves and of God. . . .Hewho, like an infant or child, has a body capable of very few things and very heavily dependent on external causes, has a mind which considered solely in itself is conscious [conscia] of almost nothing of itself, or of God, or of things. On the other hand, he who has a body capable of a great many things, has a mind which considered only in itself is very much conscious of itself, and of God, and of things. (E5p39s) The first text says that the mind perceives many things in proportion to the body's ability to do many things simultaneously or to be acted on in many ways at once. The connection between perception and a passive capacity to be acted on is clear enough. Compare a raven to a writing desk. Sound waves propagating through the air don't make any appreciable difference to the state of the writing desk, but the waves do introduce vibrations in the eardrums of the raven and subsequently change the state of its auditory nerves and the state of its brain. The raven's greater capacity to be acted on is directly related to its capacity to perceive many things. But what is the basis of the connection between the ability to do many things and to perceive many things? At minimum, a body has to have the ability to be altered by environmental inputs while maintaining the pattern of motion and rest that defines it. This requires, for Spinoza, internal actions that respond to environmental inputs in a pattern-preserving way. Thus the 9 See Bennett, A Study of Spinoza's Ethics, pp. 184–191; Della Rocca, Representation and the Mind-Body Problem, p. 9; Matson, "Spinoza's Theory of Mind," pp. 568–578; and Miller, "The Status of Consciousness in Spinoza's Concept of Mind," pp. 203–222. 10 See Garrett, "Representation and Consciousness in Spinoza's Naturalistic Theory of Imagination," pp. 4–25; Nadler, "Spinoza and Consciousness," p. 575. Spinoza and the Mark of the Mental 87 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 kinds of passive capacities that result in perception rather than destruction are directly correlated with active powers. The second text says that the more bodies are capable of, the more their associated mind is conscious of itself, God, and the world. What explains the correlation between capabilities and consciousness? Don Garrett has interpreted these texts as identifying consciousness with an idea's causal power. This identification elegantly explains the correlation between power and consciousness. Steven Nadler develops a similar interpretation. But instead of identifying consciousness with causal power, he identifies it with the categorical basis of the power of an idea, which, according to Nadler, is its structural complexity. If either of these two interpretations is correct, then consciousness cannot, for Spinoza, serve to distinguish the mental from the physical. Spinoza is clear in these texts that the power of an idea is proportional to the power of the body to which it corresponds, and it is strongly suggested by his claim that the order and connection of ideas is the same as the order and connection of bodies. The only difference between the powers of a body and the powers of its idea would be that the body has the power to produce physical effects and its idea has the power to produce mental effects. But this cannot provide us with a non-circular characterization of the mental. Thus if Garrett is correct and consciousness is grounded by causal power, consciousness cannot be, for Spinoza, the mark of the mental. We have already seen, moreover, that the mechanical structure of the mind is isomorphic to that of the body. Thus if Nadler is correct and consciousness is grounded by the categorical basis of causal power, which he takes to be mereological structure, then consciousness cannot be, for Spinoza, the mark of the mental. Intentionality as the mark of the mental. It is sometimes said, most famously by Brentano, that intentionality is the mark of the mental. And indeed, there is much that suggests that this is Spinoza's view.11 It is certainly the case that, for him, every idea represents something. The question remains, however, whether only ideas represent. Of course, if intentionality is to provide the mark of the mental, we must distinguish between the distinctive form of intentionality characteristic of the mental from other forms of intentionality. After all, on the face of it, paintings, 11 That representation is the essence of thought is defended by Michael Della Rocca in his Spinoza, pp. 89–90. 88 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 books, speech acts, and other physical things also represent. Given this, philosophers who think that intentionality is the mark of the mental typically insist that there is some difference in the way mental and nonmental entities represent. For example, the mental might represent intrinsically while physical things represent only derivatively by being used as a proxy for intrinsic intentionality. There are, indeed, two kinds of intentionality for Spinoza. The first kind pertains to the relationship that obtains between ideas and the bodies to which they are parallel and the second kind is causal/informational. The first kind of intentionality is intrinsic because it is a basic feature of ideas that depends on no external conditions. The second kind is derivative in that it depends on the causes of the intentional state and on the primitive intentionality of the first kind. In what follows, I will first argue that there is little reason to deny that the causal/informational kind of intentionality can be a property of physical things and so cannot be the mark of the mental. I will then argue that "intentional" relations between ideas and the bodies to which they are parallel lack all of the features that have led philosophers to associate intentionality with the mental, thus making it an unattractive candidate for the mark of the mental. Spinoza describes the causal/informational kind of intentionality in 2p16 and 2p16c where he gives his account of sense perception. He begins by asserting that a state of the body is determined both by the nature of the body and by the natures of any external bodies affecting it. Next, he appeals to the principle, stated in 1a4, that the idea of an effect involves and depends on the idea of its cause. Thus the idea of a state of the body involves and depends on the ideas of the natures of any external bodies affecting it. From this, he infers that "the Mind perceives the nature of a great many bodies in addition to the nature of its own body."12 What 2p16 shows is that, for Spinoza, a causal/informational link is sufficient for a mental representation. What is more, for Spinoza, the human being is deeply imbedded in a complex web of causation so that none of its parts and their processes are independent of causal inputs from the external world. For this reason, Spinoza concludes that all of our ideas of the external world as well as our ideas of our own bodies and minds have a causal/informational basis. Nothing in this account prevents physical states from representing or perceiving. Physical states involve the natures of their causes and 12 E2p16c1. Spinoza and the Mark of the Mental 89 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 thus contain information about them. Given the principles articulated previously, physical states are perceptions of the natures of their physical causes. Thus, this kind of intentionality cannot be the mark of the mental. Now it may be objected that that causal/informational links only determine what content an idea has, but not that it has content. That an idea has content is solely determined by its status as a mode of thought. Thus bodies, if they were to have content, would have whatever content their causal/informational links would determine.13 But as modes of extension and not modes of thought, they do not have content at all. This may in fact be Spinoza's view, but, although it makes intentionality necessary and sufficient for thought, it does not appear to make intentionality the mark of the mental so much as make the mental the mark of intentionality. This is because it would distinguish genuine intentional states from merely information-bearing states by requiring the genuine intentional states to be mental. Once we have analyzed intentional states as informational states that are additionally mental, we have deprived ourselves of intentionality as a possible mark of the mental. The very notion of the mental would lie too close to the surface of the notion of the intentional to provide us with anything but a viciously circular characterization. The second kind of intentionality for Spinoza is one that relates every idea to the body parallel to it in the order and connection of things. This kind of intentionality cannot be the result of causal relations because no causal relations obtain between an idea and the body parallel to it. Spinoza gives no other account of what in virtue of which these representational relations obtain, and so gives the impression that he regards them as basic or fundamental. As such, they indicate a form of intentionality that is a promising candidate for a mark of the mental: something is mental just in case it represents some body by means of basic or intrinsic intentionality. But why can't bodies represent intrinsically? Spinoza doesn't have much reason to deny that they can. To see this, consider the case of ideas of ideas. Every idea, according to Spinoza, is represented by an idea. But, Spinoza says, the idea that represents an idea is not a distinct idea, but rather it is the idea itself. In other words, every idea is self-representing. Spinoza says that the idea that represents a given idea is the form of that idea. The formal reality of an idea can be considered its own objective reality. If ideas are 13 I owe this objection to John Morrison. 90 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 allowed to represent themselves, why can't bodies? Why can't the formal reality of each body contain itself objectively? Why can't a table or a rock stand for itself? To see why this questionmight be considered a difficult one for Spinoza, let us consider the older conception of representation that was most prominent in Spinoza's day. On the model prevalent among the scholastic Aristotelians, the soul is able to represent by virtue of receiving the form without the matter of the objects being represented. When this happens, the represented thing is said to exist objectively in the soul. Things without souls cannot represent in this way because they are incapable of receiving form without matter. But if something represents itself, there is no need to receive the form without the matter. The form already exists in the thing, together with its matter. So why can't extended things represent themselves? Of course, Spinoza can answer that it is of the nature of thought to have an object, and not in the nature of extension. But, in what follows, I will argue that such an answer is unsatisfying because a closer examination of intrinsic intentionality as Spinoza conceives it reveals that it has none of the characteristics that have led philosophers to associate it with mentality. Let us consider them in turn. • The intentional object of the idea may not exist. It is commonly believed that I can think about, for example, Pegasus even if there is no such thing as Pegasus. The intentional objects of thought need not exist outside the mind. But the ability to be directed at something nonexistent seems like a very special sort of ability and one not possessed by something merely physical. Spinoza, however, denies that the intentional object may not exist. The idea of x exists only so long as x exists. He writes: From this it follows that so long as singular things do not exist, except insofar as they are comprehended in God's attributes, their objective being, or ideas, do not exist except insofar as God's infinite idea exists. And when singular things are said to exist, not only insofar as they are comprehended in God's attributes, but insofar also as they are said to have duration, their ideas also involve the existence through which they are said to have duration. (E2p8c) If an idea existed without the body it represents existing, this would be a violation of the parallelism doctrine that requires a body for every idea. To be sure, Spinoza says that the mind is not entirely destroyed when the Spinoza and the Mark of the Mental 91 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 body dies and something eternal remains. But the eternal part of the mind represents the eternal part of the body: its formal essence. So this does not break the link between intentionality and the existence of the represented object. It is true that Spinoza says that often we regard things that do not exist as present.14 But his account of this is in terms of informational states. When we are affected by an external cause, this puts our body into a state that contains information about that external cause and thus we perceive it. We will continue to be in that state until we are affected by another external cause that puts us into a state incompatible with the first state. So, for example, if light is reflected off the surface of an apple and it subsequently irradiates the retina of my eye resulting in a certain brain state that contains information about the apple, I will continue to represent the apple until my brain is no longer in a state that contains information about it, even if the apple itself no longer exists. The apple may be destroyed after I perceive it, but if this event has no causal connection to my brain, I will continue to be in a brain state that represents the apple by containing information about it. But as we have seen, this kind of representation cannot be a mark of the mental because there is little reason to suppose that physical states cannot represent in this way. • The idea can point to an object distinct from itself. It is sometimes thought that only the mental has the power to point intrinsically. That is to say, only the mind can have the intrinsic power to be about something else. Put like this, the claim might appear vague and uninformative. But regardless of how we might more precisely formulate it, it will not help Spinoza explain the difference between the mental and the non-mental. For Spinoza, in the case of intrinsic intentionality, the object must be identical to the idea of it. To the extent to which the mind can be about something external, it must be about it in the informational sense described earlier and, we have seen, there is no reason to deny that the body too has this power. • The intentional has satisfaction conditions. It is sometimes thought that only the mental can have satisfaction conditions intrinsically. There are different kinds of satisfaction conditions corresponding to different kinds of attitudes toward the intentional object. Beliefs have truth conditions. Desires have fulfillment conditions. 14 2p17c, 2p17cd, 2p17s, 2p44s. 92 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 For Spinoza, belief is associated with intellect and desire is associated with the will. Now Spinoza claims, rather strikingly, that the will and the intellect are one and the same thing. By this he means that every mental representation is at once like a belief and like a desire. This puts him at odds with philosophers such as Descartes who claim that the mind contains two very different kinds of modes: perceptions and volitions. On the Cartesian view, a perception is a representation. When a perception is the subject of a certain kind of volition (call it affirmation), it becomes a judgment or a belief. When a perception is the subject of a different kind of volition (call it wanting), it becomes a desire. The key here is that beliefs and desires are the result of two mental modes, one that represents and another that provides an attitude toward that representation. By claiming that will and intellect are one and the same thing, Spinoza is denying that beliefs and desires are composites of two kinds of mental modes, one representational and the other volitional. Furthermore, Spinoza also denies that there are any dedicated representational states associated with desire. To see this, we need to look more closely at Spinoza's theory of desire and affirmation. Spinoza's account of the conatus or striving for self-preservation that he says animates all of nature and that accounts for both affirmation in judgment and desire. Spinoza says: Each thing, insofar as it is in itself (quantum in se est), strives (conatur) to persevere in its being. (E3p6) This is a perfectly general phenomena that is true of every mode of extension and thought no matter how simple or complex. As manifested by human beings, this striving is will, appetite, and desire. Spinoza writes: When this striving is related only to theMind, it is calledWill; but when it is related to the Mind and Body together, it is called Appetite. This Appetite, therefore, is nothing but the very essence of man, from whose nature there necessarily follow those things that promote his preservation. And so man is determined to do those things. Between appetite and desire there is no difference, except that desire is generally related to men insofar as they are conscious of their appetites. So desire can be defined as appetite together with consciousness of the appetite. (E3p7) The conatus also explains the behavior of all things. By their very nature (quantum in se est), they perform those actions of which they are capable that help preserve their being or existence. Thus, according to Spinoza, Spinoza and the Mark of the Mental 93 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 every action performed by a human being is directed toward selfpreservation. What is true of human beings is also true of their parts. The simpler ideas that constitute the mind also strive for self-preservation. Each idea is disposed to produce actions that conduce to the preservation of the mind. The representational content of the idea enters into the causal story because the actions that every idea is disposed to produce are those that conduce to self-preservation on the condition that the content of the idea is accurate. In this sense, every idea contains an affirmation of its content and thus every idea is belief-like. What is more, because every idea strives for self-preservation, every idea manifests desire. Note that the cause of an action is a single idea with a single intrinsic content, which is always a state of the body. There is no intrinsic representation of the future state aimed at by the actions produced by that idea. Thus there are only intrinsic truth conditions associated with the representational content of any idea and never any intrinsic satisfaction conditions such as we would associate with desire. Moreover, the truth conditions associated with any idea are always trivially fulfilled.15 This is because, in virtue of the parallelism, an idea exists just in case its object exists. Truth conditions that are always trivially fulfilled are satisfaction conditions only in a very uninteresting sense. It is hard to see what the point of postulating satisfaction conditions that are always automatically satisfied could possibly be.16 Thus intrinsic intentionality, as Spinoza conceives it, has none of the characteristics that have led philosophers to associate it with the mental. For this reason, it seems unsuitable as a mark of the mental. We have a distinctive kind of epistemic access to the mental. A view sometimes attributed to Descartes is that the difference between the mental and the non-mental is the kind of epistemic access we have to the mental.17 This distinctive access is sometimes characterized in terms of introspection and it is sometimes said that we have superior epistemic access to our own mental states. Our knowledge of the mental is immediate, infallible, etc. Could Spinoza distinguish the mental by means of different epistemic access? I do not think that Spinoza posits an epistemic asymmetry between mind and body, but I must also concede that there is some textual evidence 15 See Bennett, Learning from Six Philosophers, pp. 189–190. 16 For further discussion of Spinoza's account of judgment, see Della Rocca, "The Power of an Idea," pp. 200–231; Lin, "Spinoza's Account of Akrasia," pp. 401–404. 17 Ryle, The Concept of Mind, pp. 3–5; Rorty, Philosophy and the Mirror of Nature, pp. 54–60. 94 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 that suggests one. I will first review this evidence and then explain why it should not be read as asserting an epistemic asymmetry. If Spinoza believes there is an epistemic asymmetry between mind and body, it is not the usual one according to which knowledge of the mind is more direct than knowledge of the body. Rather, the textual evidence sometimes appears to suggest that our knowledge of our minds is mediated by knowledge of the body. Consider, for example, the following text: However, we also cannot deny that ideas differ among themselves, as the objects themselves do, and that one is more excellent than the other, and contains more reality, just as the object of the one is more excellent than the object of the other and contains more reality. And so to determine what is the difference between the human Mind and the others, and how it surpasses them, it is necessary for us, as we have said, to know the nature of its object, i.e., of the human Body.18 Here Spinoza says that the excellence of ideas is proportional to the excellence of the bodies that they represent. For this reason, in order to know the excellence of the human mind, we must know the object of the mind, viz., the body. This can be read by the proponent of epistemic asymmetry as suggesting a difference in epistemic priority. First know the body and then, on the basis of that knowledge, know the mind. That this is Spinoza's intended meaning is further suggested later in the Ethicswhen he writes: "The mind does not know itself, except insofar as it perceives the ideas of the affections of the body."19 The proponent of asymmetry could also discern intimations of such a doctrine in Spinoza's early work the Treatise on the Emendation of the Intellect, where he writes, "there is no idea of an idea unless there is first an idea." That is, there are no second-order mental representations, mental representations of mental representations, without first-order mental representations, which are in some sense prior to them. First-order mental representations are, for Spinoza, always representations of bodies. Moreover, we have no non-representational mental states. Thus follows Spinoza's conclusion that there are no mental representations of our minds without mental representations of our body, which are, in some sense, prior to them. In other words, knowledge of the body is prior to knowledge of the mind. Despite this suggestive textual evidence, it is far from clear that Spinoza really does think that knowledge of the body is prior to knowledge of the 18 E2p13s. 19 E2p23. Spinoza and the Mark of the Mental 95 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 mind. First of all, only the early unfinished and unpublished Treatise on the Emendation of the Intellect contains any explicit mention of priority. And even there, the topic under discussion is not the epistemic priority of the body per se, but rather the acquisition of method and so it is permissible to doubt how much weight ought to be given to Spinoza's statement in the present context. Both texts from the Ethics cited previously make no explicit claims about epistemic priority. 1p13s says only that "And so to determine what is the difference between the human Mind and the others, and how it surpasses them, it is necessary for us, as we have said, to know the nature of its object, i.e., of the human Body." This can be read as merely stating some kind of entailment: necessarily, if we determine the difference between the human body and others, then we know the human body. Likewise for 2p23, which could also be read as merely asserting an entailment: necessarily, the mind knows itself if and only if it perceives affections of the body. But an entailment relation does not by itself make for priority. After all, every proposition entails itself and none is prior to itself. Indeed, it is difficult to see how Spinoza could assert any kind of priority. The reason for this derives from his views on the relationship between ideas of ideas, i.e., second-order ideas and first-order ideas. First-order ideas have bodies as their objects. Such ideas constitute our knowledge of body. Second-order ideas have ideas as their objects. Such ideas constitute our knowledge of mind. Spinoza says that our second-order ideas have the same relationship to our first-order ideas as our first-order ideas have to bodies. What kind of relationship is this? First of all, it is not explanatory. Bodies do not explain our ideas of bodies. If the relationship between second-order ideas and bodies is the same as the relationship between first-order ideas and bodies, then firstorder ideas do not explain our second-order ideas. Second, first-order ideas and bodies are one and the same thing conceived under two different attributes. We must infer from this that second-order ideas and first-order ideas are one and the same thing conceived of differently (although under the same attribute). And indeed Spinoza explicitly affirms this conclusion when he writes: "the idea of the idea, is nothing but the form of the idea insofar as this is considered as a mode of thinking without relation to the object."20 In other words, second-order ideas are identical to the ideas that they represent. First-order ideas thus represent 20 E2p21s. 96 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 themselves and there is but a distinction of reason between them and the second-order ideas that represent them. Materialism, Idealism, and Monism None of the candidates for the mark of the mental that we considered have succeeded. Is this because we have been considering the wrong candidates, or is there a deeper reason to be found in Spinoza's metaphysics of mind and body? In this section, I will argue that there is a deeper reason: any explicit characterization or mark of one attribute entails for Spinoza that the other attributes must lack such a mark on pain of entailing forms of metaphysical dualism that Spinoza seeks to avoid. The precise nature of Spinoza's metaphysics of mind and body is a contentious issue with nearly every imaginable interpretation finding adherents. A large number of commentators have thought that Spinoza is a substance dualist.21 On this view, each attribute is itself a substance and Spinoza is a monist only in the sense that mental and physical substance compose to form a third substance and there is only one such comprehensive substance. (Here as elsewhere I am ignoring the complications introduced by Spinoza's obscure doctrine of the unknown attributes.) Still others allege that he is a materialist.22 There are those who claim that he is an idealist or at least that his system pushes him in that direction.23 Another popular interpretation is that he is a dual aspect theorist or a property dualist.24 What are we to make of Spinoza's capacity to attract a nearly exhaustive array of mutually exclusive interpretations? It is almost enough to make one suspect that Spinoza's philosophy of mind must be nothing more than an incoherent farrago of fragmentary doctrines out of which almost any metaphysics of mind can be assembled. This is, I believe, not the case, but nevertheless a truly successful interpretation of Spinoza's philosophy would explain how it manages to attract such diverse interpretations. 21 Gueroult, Spinoza I, 232; Donagan, "Spinoza's Dualism," pp. 115–129. 22 Hampshire, "A Kind of Materialism," pp. 5–23; Negri, The Savage Anomaly, p. 65 and 155; Montag, Bodies, Masses, Power, p. 57. 23 Hegel, Lectures on the History of Philosophy, p. 260; Martineau, A Study of Spinoza, p. 189; Murray, "The Idealism of Spinoza," p. 474. 24 Bennett, A Study of Spinoza's Ethics, p. 41; Della Rocca, Representation and the Mind-Body Problem, chapter 9. Spinoza and the Mark of the Mental 97 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 Of all of these interpretations, I believe, the anti-dualist interpretations are closest to the mark.25 But Spinoza was neither a materialist nor an idealist, at least not in the sense that one doctrine is supposed to exclude the other. He is a metaphysical monist and a conceptual dualist.26 For Spinoza, whether or not something is mental or physical is a matter of how it is conceived. Moreover, anything can be accurately and adequately conceived as mental or as physical. Under the mental way of conceiving, the whole story of the world can be told truthfully and without leaving anything out. Likewise, under the physical way of conceiving, the whole story of the world can be told without leaving anything out. Each attribute, in other words, is a different way of thinking about the same thing and its history. This explains why Spinoza's metaphysics of mind has been interpreted in such multifarious ways. When the materialist gives her account of the world, Spinoza is in a position to agree with all her particular claims. (But not her universal generalizations like "There are no ideas.") Likewise with the idealist. Someone who observes Spinoza agreeing with both the materialist and the idealist might well conclude that, for him, both the physical substance and the mental world are equally real. Hence substance dualism. Alternatively, if emphasis is placed on the accuracy of perceiving the world as both extended and thinking, then one is likely to conclude that Spinoza is a property dualist. Spinoza does think that extension and thinking are equally real, but not because he is a metaphysical dualist. Rather, they are equally real because they are the very same things or features conceived of differently. For such a conceptual dualism to succeed, it must be the case that our concepts of the attributes are individuated in such a way that they imply no metaphysical difference in the world. How is this possible? They cannot be individuated by their contents because they have the same contents. It is thus natural to think that they must then be individuated by how those contents are presented. How are we to think of modes of presentation in this context? It is common for philosophers after Frege to think of modes of presentation descriptively. For example, the content of the name "Hesperus" might be presented under the description "the brightest star 25 I develop and defend this interpretation in my "Spinoza on the Metaphysics of Thought and Extension," in the Cambridge Companion to Spinoza, forthcoming. 26 The idea that the distinction between the attributes is merely a distinctio rationis goes back to at least Wolfson, but it is decidedly more popular among non-specialists than specialists. See, e.g., Heil, Philosophy of Mind, p. 185. 98 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 in the evening sky" and the content of the name "Phosphorus" under the description "the brightest star in the morning sky." But the individuation of modes of presentation by associated description entails metaphysical difference. That Venus has two such modes of presentation requires that it also has two distinct properties: it must have the property of being the brightest star in the morning sky and it must have the property of being the brightest star in the evening sky. Otherwise it would not satisfy both descriptions.27 For this reason, mental concepts and physical concepts cannot be individuated by descriptive modes of presentation for Spinoza. If they were, the objects to which they apply would need to have different properties by virtue of which they satisfied the distinct modes of presentation, and this would undermine Spinoza's monism.28 What Spinoza needs instead are modes of presentation that are not individuated descriptively. This helps us to understand why we have not been able to identify a mark of the mental that is compatible with Spinoza's system. All of the attributes are on par. They must be treated symmetrically. Thus the mental is substantively characterized just in case the physical is substantively characterized. Any substantive characterization of the mental that can serve to distinguish it from the physical would entail that substance satisfies two descriptions: the mark of the mental and the mark of the physical. This in turn would entail a metaphysical distinction between properties. We have so far neglected the attribute of extension. I have claimed that Spinoza must not substantively characterize it on pain of dualism. Is this borne out by Spinoza's philosophy? The term extension suggests Euclidean three-dimensional space. If the attribute of extension were Euclidean space, then a substantive characterization of it would be available in terms of something like the axioms and definitions of Euclid's' Elements. But there are many reasons that suggest such an interpretation would be incorrect. For example, in his correspondence, Spinoza denies that his conception of extension is the same as Descartes' and he asserts that it must have a dynamic aspect.29 Clearly this does not describe Euclidean three-dimensional space. What, then, is extension? Spinoza is appropriately silent. 27 See Smart, "Sensations and Brain Processes," p. 148. Smart attributes this point to Max Black. 28 Although we both think that the difference between the attributes is merely conceptual, I reject Noa Shein's interpretation in her "The False Dichotomy Between Objective and Subjective Interpretations of Spinoza's Attributes," pp. 529–531, for this reason. 29 Ep. 83; see also 1p16, 1p16d. Spinoza and the Mark of the Mental 99 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 What leads Spinoza to postulate a conceptual dualism between mind and body in the first place? Why not rest content with some kind of more straightforward monism, for example, materialism or idealism? It is impossible to say with certainty, as Spinoza never addresses the question. He more or less simply asserts his dualism and then explores some of its consequences. Perhaps this starting point can be accounted for by the fact that Spinoza wanted to explain why various forms of dualism have dominated Western philosophy, beginning with ancients like Plato and running through the history of the Latin West in the form of Christian Aristotelians (who were indeed dualist even if not Cartesian dualists).30 His explanation is that we are equipped with two sets of concepts that bear no a priori connections to one another. Because they lack such connections, philosophers have taken them to apply to very different kinds of objects or to express very different kinds of properties. In reality, according to Spinoza, they are nothing but the products of conceptual redundancy. Spinoza tries to offer an explanation of this conceptual redundancy, but his answer is far from satisfactory. In order to remain tolerably close to Spinoza's own formulation of his reasons, we must now drop the pretense that thought and extension are the only two attributes. I have been speaking of Spinoza's conceptual "dualism," but, strictly speaking, he is no dualist. Rather he is a conceptual pluralist of a rather extreme variety. He believes that there are infinitely many attributes but, for some reason, thought and extension are the only two known by us. The underlying justification for this claim seems to be the thought expressed in E1p9: the more reality something has, the more attributes it has. God is the most real being possible. Therefore, God has infinitely many attributes. But the conclusion does not follow from the premises. The most we ought to conclude is that God has every possible attribute. It does not appear that this line of reasoning could tell us how many possible attributes there are. This does not mean that I think Spinoza's position is completely unmotivated. The observation that metaphysical dualism is widespread is certainly correct and just as certainly calls out for explanation. Inferring metaphysical difference from merely conceptual difference is a very promising explanation of this putative error. 30 See Rozemond, Descartes' Dualism, pp. 38–41. 100 martin lin 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D:7 Conclusion In this chapter, I have argued that Spinoza provides us with no mark of the mental and, indeed, all of the most promising candidates for the mark of the mental are not even compatible with the explicitly stated commitments of Spinoza's philosophy. I have further argued that these incompatibilities are entailed by Spinoza's monism. Both extension and thought cannot be substantively characterized on pain of metaphysical dualism. Spinoza and the Mark of the Mental 101 3 B 697 B7 D7B C 8 C7 3 3 3 7 3D :DD C 53 B 697 B9 5 B7 D7B C :DD C 6 B9 . 3676 8B :DD C 53 B 697 B9 5 B7 , CD 2 7BC D 1:7 9 0 B3B / 3D C 75D D D: