Can the Berkeleyan Idealist Resist Spinozist Panpsychism? forthcoming in Logical Analysis and History of Philosophy (penultimate draft; please cite published version) Graham Clay, University of Notre Dame Michael Rauschenbach, Washington University in St. Louis School of Medicine Abstract We argue that prevailing definitions of Berkeley's idealism fail to rule out a nearby Spinozist rival view that we call 'mind-body identity panpsychism.' Since Berkeley certainly does not agree with Spinoza on this issue, we call for more care in defining Berkeley's view. After we propose our own definition of Berkeley's idealism, we survey two Berkeleyan strategies to block the mind-body identity panpsychist and establish his idealism. We argue that Berkeley should follow Leibniz and further develop his account of the mind's unity. Unity-not activity-is the best way for Berkeley to establish his view at the expense of his panpsychist competitors. 1. Introduction In teaching, when we need a paradigmatic idealist, we point to Berkeley. Whether Leibniz and Kant are idealists is complicated-or so we tell our students-but Berkeley, he is an idealist. This confidence flows from a broad consensus that Berkeley is an idealist.1 Given the breadth of this consensus, one might naturally assume that there is a definition of his idealism that enjoys the status of a standard and also distinguishes his position from nearby competitors. In this paper, we argue that the prevailing definitions of Berkeley's idealism fail to explicitly rule out a nearby rival view endorsed by Spinoza that we call 'mind-body identity panpsychism.' Since Berkeley certainly does not agree with Spinoza about mind-body identity panpsychism, we call for more care in defining Berkeley's view. Next, we argue that this problem is a symptom of broader definitional issues surrounding idealism and panpsychism. We then propose a more discriminating definition of Berkeley's idealism. Finally, we survey two Berkeleyan lines of thought which might help Berkeley block the mind-body identity panpsychist and establish his idealism. We argue, with reference both to challenges presented by Spinoza and to problems with contemporary formulations of the view, that Berkeley should follow Leibniz and further develop his account of the unity of the mind. Berkeley must differentiate between minds and bodies to separate himself from his panpsychist competitors. The alternative differentiator, the mind's activity, is important to Berkeley but it is not up to the task. 1 An anonymous reviewer points out that despite Berkeley's status as the idealist par excellence in philosophy today, Berkeley himself never uses the term 'idealism,' which is most likely an invention by later German philosophers and historians of philosophy in the mid to late 1700s. Indeed, Wolff may be its inventor (see Guyer & Horstmann 2018). Graham Clay & Michael Rauschenbach 2. Incomplete Definitions Since the definitions of Berkeley's idealism one finds in the literature converge significantly, there seems to be something of a standard or, at least, several nearby standards. However, these definitions all fail to distinguish Berkeley's position from a nearby rival view. Consider the following definitions: A. Ordinary objects are only collections of ideas, which are mind-dependent. (Flage 2018, Sec. 4) B. Reality consists exclusively of minds and their ideas. (Downing 2013, Introduction) C. Sensible objects and their sensible properties are nothing more than mind-dependent entities. (Rickless 2013, 1) D. The only kinds of things there are in the world are minds and ideas. (Rickless 2013, 9) E. All that exists is either mind or is dependent on mind. (Hausman & Hausman 1995, 64) The first and third of these definitions reflect Berkeley's own strategy of expressing his view negatively as the rejection of all positions, from physicalism to dualism, that affirm the existence of bodies (or their constituent qualities) independent of minds. Yet, both definitions are compatible with mind-body identity panpsychism. This is the rival view that every body is identical to some mind and every mind is identical to some body. As versions of Berkeley's famous slogan-esse est percipi (aut percipere), to be is to be perceived (or to perceive)-the other three definitions do no better. As stated, they all are compatible with mind-body identity panpsychism. We treat the kind of dependence referenced by these definitions as dependence with respect to existence: necessarily, for all x and all y, x depends on y if, and only if, necessarily, if x exists, then y exists. Necessarily, for all x and some mind y, x is mind-dependent if, and only if, necessarily, if x exists, then y exists. Clearly, this definition of dependence does not entail asymmetry between the dependent thing and what it depends on, a feature that must be kept in mind in what follows despite its perhaps counterintuitive ring in English. It is thus a more general definition of dependence than the asymmetrical one that Berkeley often seems to have in mind. On our definition, for instance, for all minds x, if x exists, then x is mind-dependent, because necessarily, for all minds x, if x exists, then some mind (that very x) exists. If Berkeley's idealism is to be distinguished from mind-body identity panpsychism, asymmetry must be explicitly stated as part of its definition, not assumed as part of what it means for one thing to depend on another, a point we return to at length later in the paper. This definition of dependence (what we call "dependence with respect to existence") also differs from Spinoza's definition of dependence. Given his importance as Berkeley's interlocutor in this paper, it is crucial to clarify how our definition interacts with Spinoza's. Two features of Spinoza's views deserve comment. First, Spinoza's notion of dependence is attribute-specific, meaning that Can the Berkeleyan Idealist Resist Spinozist Panpsychism? Spinozist dependence relations hold only between, for example, extended things, either Substance or modes, and other extended things, and they never hold between modes of different attributes, such as between thinking and extended modes.2 Spinoza makes this clear in EIIp6, writing that "The modes of each attribute have God as their cause insofar as he is considered under the attribute of which they are modes, and not insofar as he is considered under any other attribute," although his argument there ultimately appeals to EIp10, which asserts the independence of each attribute from every other. Second, there is substantial overlap between the various types of dependence Spinoza discusses, including being caused by, being conceived through, inhering in, and others, although Spinoza's interpreters disagree about the extent of overlap.3 Under our definition of dependence, mind-body identity panpsychism, whose defenders include Spinoza, entails that every body depends on some mind and every mind depends on some body. If ordinary objects are only collections of ideas, which are mind-dependent (A), then mind-body identity panpsychism could be true as well, given that ordinary objects would be dependent on minds if they were identical to minds, which are just collections of ideas of varying complexity for Spinoza (EIIp15). If sensible objects and their sensible properties are nothing more than mind-dependent entities (C), then mind-body identity panpsychism could be true as well, given that sensible objects would be dependent on minds if they were identical to minds and their properties would be dependent on minds if they were identical to properties of minds. If all that exists is either mind or is dependent on mind (E), then mind-body identity panpsychism could be true as well, given that all that exists could be a mind or dependent on one if all bodies were identical to minds. And so it goes for the rest of the definitions. None of the definitions of Berkeley's idealism is inconsistent with mindbody identity panpsychism.4 2 And while modes of a given attribute depend on Substance, considered under the attribute of which they are modes, Substance never depends on its modes. 3 See Newlands 2018, 57-59, for a partial catalog of the myriad terms Spinoza uses to discuss types of metaphysical dependence. Samuel Newlands (2018, 57-89) offers an extended argument for identifying all relations of metaphysical dependence in Spinoza's ontology, such that every dependence relation is identical to every other, and for the claim that all dependence relations are ultimately conceptual, a view he calls 'Conceptual Dependence Monism.' Michael Della Rocca (2008 and 2012) appears to endorse something like Newlands' view, whereas Mogens Laerke (2011, 449) and Francesca Di Poppa (2013, 306, 317) both appear to endorse the fundamentality of causal over conceptual or inherence relations. Finally, Yitzhak Melamed (in 2013a and elsewhere) has raised issues for identifying inherence relations with causal and conceptual relations. However, virtually all interpreters read Spinoza as committed to attribute-specific dependence relations, at least some of which are either co-extensive or identical with some others. Since we are primarily interested in the single broad claim about existential dependence defined in the body of the paper, we do not take a stand on these more sophisticated debates in the literature on Spinoza, though for ease of exposition we will often talk as if Newlands' and Della Rocca's views are correct. 4 Stefan Storrie (2018, esp. 161-165) discusses a list of four possible interpretations of Berkeley's idealism that is in many ways close to our (A-E) list. We are almost wholly sympathetic to Storrie's arguments, which show in various ways the gaps remaining in Berkeley's arguments for idealism if it is interpreted in one of the four ways Storrie discusses. However, since Storrie is focused on different Berkeleyan interlocutors than Spinoza, there are fewer points of contact between Storrie's discussion and ours than it may seem, despite the similar lists that serve as starting points for our respective discussions. Specifically, Storrie imagines Berkeley's interlocutor as defending a broadly Cartesian view of extended substance, as something radically different from mental substance, which underlies or supports sensible things or ideas. But Spinoza, the Berkeleyan interlocutor we engage most here, thinks that mental Substance is Graham Clay & Michael Rauschenbach However, the two aforementioned features of Spinoza's views on dependence must be kept in mind when assessing our claim that Berkeley's definitions (A-E), as stated, are compatible with mindbody identity panpsychism as exemplified by Spinoza. Consider the case of definition C. Spinoza would reject the claim that sensible objects and their sensible properties are nothing more than minddependent entities (C) since he would understand 'mind-dependent' as misapplied unless it were used to refer to his own definition of dependence, according to which all dependence relations are attribute-specific.5 For Spinoza, sensible objects and properties likely belong to the attribute of Extension, and so depend only on other extended things, per EIIp6 and EIp10.6 Nonetheless, he cannot deny that sensible things, taken as extended, and minds, as specified in definition C, depend on one another by our definition, whether or not he would deny that this constitutes dependence by his definition.7 Spinoza cannot reject this because, according to EIIp7s, "A mode of extension and the idea of that mode are one and the same thing, but expressed in two ways." If sensible objects and sensible properties are extended modes, then they are identical to, or one and the same thing as, thinking modes, per EIIp7s. Thus, necessarily, for all sensible things and their corresponding thinking modes (or ideas), if the sensible thing exists, its corresponding idea exists. But this just is dependence by our definition, so Spinoza must accept the content of definition C.8 In this paper, we employ our definition of dependence, whose existential entailment claims Spinoza accepts, despite the underlying disagreements just outlined, and focus our attention on the asymmetrical dependence claims between the minds and ideas that are crucial to Berkeley's idealist project. Our concern is with how these claims are formulated and how Berkeley can best justify them. identical to extended Substance (as opposed to radically different), and he precludes any dependence relations between his Substance, taken as extended, and mental modes such as ideas, in virtue of EIIp6 and EIp10 (which assert the independence of each attribute from all the others). Storrie's arguments, while persuasive, are aimed at different targets than the one we focus on here. 5 We focus on definition C here, but similar remarks could be made about the others. We thus intend our discussion here to account for the discrepancy across the board between our notion of dependence and Spinoza's. 6 This is somewhat unclear, since the terminology of "sensible things" is far less important to Spinoza than it is to Berkeley. But since Berkeley argues that sensible things are ideas that depend on minds (and some such ideas are bodies or parts of bodies), we think it is fair to treat sensible things as if at least some of them were extended, since the point of contention between Berkeley and Spinoza concerns bodies. 7 The subtleties involved in comparing Spinoza's views on dependence to the definition of dependence we have given here parallel in important ways the discussion of so-called "attribute neutrality" in Spinoza's Ethics, as discussed, for example, in Bennett 1984, 144-145, Newlands 2018, 245-249, and Melamed 2013, 645-646. As Melamed puts it (646), we need some way of speaking of trans-attribute units of modes-of modes of a specific attribute ("Modes of an Attribute")-and modes under all attributes ("Modes of God"). Translating our discussion of dependence into Melamed's terminology, we can say that bodies or sensible objects (as "Modes of Extension") cannot depend on minds (as "Modes of Thought"). However, since body b and mind m are the same Mode of God, necessarily, if m exists, b exists, and vice versa. It is the attribute-neutral claim (or claim about the Modes of God) that secures the identity of b and m and licenses our claim that b depends on m with respect to existence. So although we acknowledge that Spinoza restricts dependence claims to within modes of a single attribute, we also think it important to note that, given that b and m are the same Mode of God, one cannot exist without the other. 8 With the same caveat as before that while modes depend on Substance, considered under the attribute of which they are modes, Substance itself never depends on its modes in any way. Can the Berkeleyan Idealist Resist Spinozist Panpsychism? The foregoing discussion shows that mind-body panpsychism is a rival of Berkeley's idealism, as is clear from consideration of Spinoza's version of this more general view. As stated above, Spinoza holds that "a mode of extension and the idea of that mode are one and the same thing, but expressed in two ways" (EIIp7s). Moreover, for Spinoza divine and human minds just are more or less complex ideas (EIIp15). Every composite body is identical to a complex idea and constitutes the Extended object of that complex mind in Thought. To hold mind-body identity panpsychism is to deny Berkeley's idealism since, among other reasons, Berkeley's ontology contains a wholly immaterial God and finite, wholly immaterial spirits. Spinoza denies both. Likewise, Berkeley's view that minds are not ideas cannot be simply assumed and ought to be explicitly stated by any definition of his idealism, given the arguments-Spinoza's or otherwise-for the contrary claim that minds just are ideas. Berkeley's arguments for the non-identity of mind and body that rely on this view (and the claim that bodies are collections of ideas) ought to be treated as contested.9 Of course, as noted, Berkeley's idealism has other rivals since some physicalists think that all minds are identical to bodies, but that some bodies are not minds or dependent on them, and dualists hold that mind-independent bodies and minds both exist. Both these alternative rival views are explicitly excluded by the preceding definitions. Although Spinoza's position is a rival to Berkeley's, Berkeley shares more with Spinoza than with some of his other rivals. Notably, Spinoza argues that his mind-body identity panpsychism is a direct consequence of his views on God, which he establishes with the help of ontological and cosmological arguments similar in ways to those employed by the Christian tradition of which Berkeley is a part. So, while the historical context Berkeley found himself in demanded engagement with physicalists and dualists, he potentially faces a graver threat from Spinoza. 3. Incomplete Arguments Before offering our own definition of Berkeley's idealism that explicitly excludes mind-body identity panpsychism, we must address a natural objection. Given that mind-body identity panpsychism is neither one of Berkeley's targets nor a prevalent view, one could argue that those who give definitions of Berkeley's idealism-whether they are his commentators or Berkeley himself-are not obligated to formulate it in such a way that it explicitly precludes mind-body identity panpsychism. One might think that how philosophers define views is largely stipulative and depends on the dialectical contexts they find themselves in. So, while the definitions of Berkeley's idealism found in the literature fail to explicitly preclude mind-body identity panpsychism, this is not a problem. After all, Berkeley's arguments for his idealism clearly rule out mind-body panpsychism. This objection amounts to the claim that the premises of some of Berkeley's arguments for his idealism 9 To be clear, our concern is not with Berkeley's claim that all bodies are ideas, since Spinoza's mind-body identity panpsychism commits him to accepting that all bodies are ideas as well (and vice versa, of course). Rather, we focus instead on Berkeley's claim that minds are not ideas, given Spinoza's defense of the contrary position that minds are just complex ideas, as EIIp15 indicates explicitly and as Spinoza's general ontology commits him. Graham Clay & Michael Rauschenbach entail the negation of mind-body identity panpsychism, so if their conclusions are formulated to express all of their entailments, mind-body panpsychism is ruled out. In this section, we will argue that this claim is false. Choosing which argument to examine is no easy matter. There is little dispute that Berkeley is, in fact, an idealist, but it is not settled how his arguments for idealism should be understood. It is often argued that his main strategy is to grant or argue for the mind-dependence of certain "sensible qualities" and then attempt to undermine various distinctions between these qualities and others in order to establish his idealism. In discussing this strategy, some commentators focus on Berkeley's perceptual relativity arguments, while others focus on his inseparability argument.10 Recently, it has been proposed that this latter argument is unique in bringing together several seemingly independent lines of reasoning that Berkeley develops elsewhere to support his idealism.11 Given our goals, it is not feasible for us to present and discuss all of the arguments in Berkeley's texts that have been proposed as arguments for his idealism. Since the inseparability argument is, as of late, taken to be either Berkeley's strongest argument for idealism or one of them, it is as good of a choice as any. What makes the inseparability argument unique is that Berkeley uses it, fittingly, to argue for the inseparability of the primary and secondary qualities. There are different ways of understanding how the argument proceeds. The argument is found in both the Principles (PHK 10) and the Dialogues (3D 194), but what follows is our formulation of it as Berkeley expresses it in the Principles. Here is Berkeley: They who assert that figure, motion, and the rest of the primary or original qualities do exist without the mind, in unthinking substances, do at the same time acknowledge that colours, sounds, heat, cold, and such like secondary qualities, do not, which they tell us are sensations existing in the mind alone, that depend on and are occasioned by the different size, texture and motion of the minute particles of matter. This they take for an undoubted truth, which they can demonstrate beyond all exception. Now if it be certain, that those original qualities are inseparably united with the other sensible qualities, and not, even in thought, capable of being abstracted from them, it plainly follows that they exist only in the mind. But I desire any one to reflect and try, whether he can by any abstraction of thought, conceive the extension and motion of a body, without all other sensible qualities. For my own part, I see evidently that it is not in my power to frame an idea of a body extended and moved, but I must withal give it some colour or other sensible quality which is 10 Those who defend the traditional "inherence account" are focused on the former. For classic statements of the inherence account, see Allaire 1963 and Watson 1963. Others who have a similar, but distinct, focus include David Hausman and Alan Hausman (1995). 11 Samuel Rickless has recently argued forcefully for a version of this interpretation. For a summary of Rickless' interpretation and the role the inseparability argument plays for Berkeley, see Rickless 2013, 185-187. Lisa Downing (2018) argues that the inseparability argument blocks a path that Berkeley's non-idealist interlocutors could have used to escape his attacks, if Berkeley only had the perceptual relativity arguments and his arguments from the immediacy of perceived things at his disposal. Can the Berkeleyan Idealist Resist Spinozist Panpsychism? acknowledged to exist only in the mind. In short, extension, figure, and motion, abstracted from all other qualities, are inconceivable. Where therefore the other sensible qualities are, there must these be also, to wit, in the mind and no where else. (PHK 10) Berkeley's argument for the first premise (P1), which we have not included, relies on the received view about the mind-dependence of phenomenal secondary qualities that is held by Descartes, Locke, and many other non-idealists. Here, following Locke but using contemporary terminology, we contrast phenomenal secondary qualities (e.g. a particular shade of red that you see when viewing a tomato) with dispositional secondary qualities (e.g. the disposition of a tomato to cause you to see a particular shade of red when viewing it). The crucial point is that Locke holds that the former are represented by us as belonging to mind-independent bodies but they are in fact mind-dependent. P1. It is not possible that there is a mind-independent being that has phenomenal secondary qualities. [granted by many opponents, perceptual relativity arguments, identification argument] P2. For all p, if it is inconceivable that p because it is a contradiction that p, then it is not possible that p. [Berkeley's inconceivability principle, according to Thomas Holden] P3. If it is inconceivable that there is a body that exists without having phenomenal secondary qualities in fully determinate and non-contradictory ways because it is a contradiction that there is a body that exists without having phenomenal secondary qualities in fully determinate and non-contradictory ways, then it is not possible that there is a body that exists without having phenomenal secondary qualities in fully determinate and non-contradictory ways. [P2] P4. If it is not possible that there is a body that exists without having phenomenal secondary qualities in fully determinate and non-contradictory ways, then it is not possible that there is a mind-independent body. [P1] P5. For all x, x is a body if, and only if, x has all of the primary qualities in fully determinate and non-contradictory ways. [Locke's definition of 'body,' Berkeley's nominalism] P6. For all x, if x is a quality and a fully determinate and non-contradictory way of being extended, figured, or mobile, then x is a primary quality. [Locke's definition of 'primary quality,' Berkeley's nominalism] Graham Clay & Michael Rauschenbach P7. For all x, x is a body if, and only if, x has extension, figure, and mobility in fully determinate and non-contradictory ways. [P5, P6] P8. For all x, if x has extension, figure, and mobility in fully determinate and noncontradictory ways, then x has phenomenal secondary qualities in fully determinate and non-contradictory ways. [Berkeley's inseparability principle, Berkeley's nominalism] P9. It is a contradiction that there is a body that exists without having phenomenal secondary qualities in fully determinate and non-contradictory ways. [P7, P8] P10. It is inconceivable that there is a body that exists without having phenomenal secondary qualities in fully determinate and non-contradictory ways because it is a contradiction that there is a body that exists without having phenomenal secondary qualities in fully determinate and non-contradictory ways. [P9, Berkeley's view on the inconceivability of contradictions] C. So, it is not possible that there is a mind-independent body. [P3, P4, P10] The traditional view is that the inseparability argument relies centrally on a principle that moves from inconceivability to impossibility: for all p, if it is inconceivable that p, then it is not possible that p. This principle would take the place of P2 above; call it P2*. A virtue of the traditional view is that it does not require the attribution of a strong metaphysical inseparability premise like P8 to Berkeley. P8 is needed to generate the requisite contradiction. Instead, the traditional view can simply attribute a premise that asserts that the primary and phenomenal secondary qualities cannot be conceived apart. A cost of the traditional view is that P2* does not seem to be endorsed by Berkeley. Thomas Holden (2019) convincingly argues that Berkeley holds that there are cases where we cannot conceive something but nonetheless it is possible. However, for those cases where we cannot conceive something because it is contradictory, then it is in fact impossible. After all, everything that is contradictory is impossible, on Berkeley's view (and that of many of his contemporaries). Or so Holden's argument goes. Thus P2 and P8. There is much to be said about the argument itself, but we will limit ourselves to three points. First, no subset of the premises entails the negation of mind-body identity panpsychism; the mindbody identity panpsychist could endorse all of the premises of the inseparability argument. Second, none of the premises provide anything like non-question-begging reasons for the negation of mindbody identity panpsychism. Berkeley might simply add the negation of mind-body identity panpsychism as an assumption, but this would beg the question. None of the premises to which he is entitled, and for which he has provided some compelling independent motivation in making his inseparability argument, entail the negation of mind-body identity panpsychism. Third, in analyzing Can the Berkeleyan Idealist Resist Spinozist Panpsychism? this argument, we can see why commentators end up with definitions like those listed in the prior section (especially A and C). Berkeley's own argumentation is not sensitive to the challenge presented by the mind-body identity panpsychist. 4. A Definitional Digression In noting that both common definitions of Berkeley's idealism and his most prominent arguments fail to distinguish his ontological position from mind-body identity panpsychism, we do not mean to criticize Berkeley. We grant that the dialectical context Berkeley found himself in as he presented his views about the mind did not demand direct engagement with mind-body identity panpsychism. Our goal is simply to show that more care must be taken to get clear on the precise nature of Berkeley's idealism, given the early modern option space as well as burgeoning recent interest in nearby panpsychist views. Since we seek to offer an improved-even if still incomplete-definition of Berkeley's idealism, contemporary attempts to define idealism and panpsychism are natural starting points, although these discussions are themselves fraught with disagreement. Nevertheless, we turn there first, before considering whether Berkeley can justify his preference for idealism over a mindbody identity panpsychist alternative. In introducing Idealism: New Essays in Metaphysics, Tyron Goldschmidt and Kenneth Pearce register the difficulties associated with defining idealism, before glossing both idealism in general and Berkeley's idealism in particular. They write: Roughly speaking, we may say that idealists endorse the priority of the mental [...]. George Berkeley's view that minds and their ideas are all the beings there are is the most famous version of idealism. According to Berkeley, minds enjoy ontological priority: minds alone are fundamental and everything else depends on them. (Goldschmidt & Pearce 2017, ix) Other contributors to the same volume gather related theses under the banner of idealism, including Robert Adams' claim that "all intrinsic non-formal qualities must be qualities of consciousness or strongly analogous to qualities of consciousness" (2017, 2), Robert Smithson's assertion that "truths about ordinary objects and their manifest properties supervene on truths about actual and possible counterfactual experiences" (2017, 18), and Segal and Goldschmidt's characterization of idealism as "the view that all concrete things are purely mental" (2017, 35). These definitions all have their problems. Smithson's supervenience formulation of idealism, like pure supervenience formulations of physicalism, fails to capture the notion of asymmetric dependence that Jaegwon Kim and others have argued is central to any non-trivial supervenience definition.12 Aaron Segal and Goldschmidt admit that their definition is consistent with "the world being thoroughly physical, wholly physical, physical through and through [...]. That would be the case 12 Kim (2005, 34) argues that supervenience needs ontological dependence too. See also Wilson 2005 for a catalog of the problems with supervenience-based formulations. Graham Clay & Michael Rauschenbach if every mental aspect of the universe were itself physical, and vice versa" (2017, 34). Adams' view faces the same problem, since intrinsic non-formal qualities of consciousness might be wholly physical qualities in addition. These latter views thus appear to countenance something like Spinoza's monistic view that "the thinking substance and the extended substance are one and the same substance, which is now comprehended under this attribute, now under that" (EIIp7s). But, as Samuel Newlands and Yitzhak Melamed have argued at length, Spinoza cannot be an idealist, for idealism introduces incoherence into his philosophical system, in violating EIp10.13 Definitions of panpsychism do not fare much better. David Chalmers, for instance, defines panpsychism as "the thesis that some microphysical entities are conscious" (2016a, 24). As stated, this view is consistent with Segal and Goldschmidt's definition of idealism, since if all concrete things are purely mental (per their definition of idealism) and all microphysical things are concrete, then all microphysical things are purely mental. If all purely mental things are conscious, then trivially some microphysical things are conscious, but this is Chalmers' definition of panpsychism. Yet, the views are clearly intended to be distinct. As Godehard Brüntrup and Ludwig Jaskolla discuss in their introduction to Panpsychism: Contemporary Perspectives, "Panpsychists in contrast claim that mental being is a fundamental and ubiquitous feature of the universe but is not the only fundamental and ubiquitous feature of the universe [...]. It is thus distinguished from absolute idealism, according to which the world consists solely of minds and their activities" (2016, 1). Other panpsychists, however, appear to disagree. Galen Strawson, for instance, describes his view as "a form of pure panpsychism, which I here take to be the view that experientiality is all there is to the intrinsic nature of concrete reality" (2016, 81). This, of course, sounds like Segal and Goldschmidt's claim that idealism is the view that all concrete things are purely mental, but Strawson apparently denies that there are other non-mental fundamental features of the universe (so the purely mental is not also purely physical).14 If this latter part of Strawson's view is indeed a commitment, then his panpsychism runs afoul of the definition from Brüntrup and Jaskolla. Finally, there is what Chalmers labels 'constitutive Russellian panpsychism,' according to which [...] microphenomenal properties serve as quiddities, playing the roles associated with microphysical properties, and also serve as the grounds for macrophenomenal properties [...]. One could think of the world as fundamentally consisting in fundamental entities bearing fundamental microphenomenal properties, where the microphenomenal properties are connected to each other (and perhaps to other quiddities) by fundamental laws with the structure that the laws of physics describe. (Chalmers 2016, 254-255) On this view, microexperience is fundamental, grounding macroexperience while serving as the quiddity occupying all microphysical roles. So, pace Brüntrup and Jaskolla, Chalmers holds that the 13 Newlands 2012 and 2018, esp. chapter 9, and Melamed, 2013. Ethics Ip10 is central not only to Spinoza's views on the mind-body problem, but also to all his central arguments concerning God in Ethics Part I. 14 See Strawson 2006, 238-242. There Strawson considers the possibility that the purely mental is also purely physical. Since he gives some reasons to be skeptical, we interpret him as tentatively denying this identification. Can the Berkeleyan Idealist Resist Spinozist Panpsychism? questions of fundamentality and ubiquity come apart: being mental is alone fundamental but being mental and being physical are both ubiquitous features of the world. To exit this definitional morass, reconnect with prevailing definitions of Berkeley's idealism, and emphasize the crucial differences between Berkeley's project and contemporary ones, we propose the following theses for consideration: Strong Asymmetry: (1) Necessarily, for all x, if x is a mind, then x does not depend on a body, and (2) necessarily, for all x, if x is a body, then x depends on a mind. Mental Substances: Necessarily, for all x, if x is a mind, then x is a substance. Existence: There are minds, there are bodies, there are mind-dependent beings that are not bodies, and there is nothing else. Berkeley's Idealism: Strong Asymmetry, Mental Substances, and Existence. Our definition has the following virtues. First, it is consistent with all of the definitions given at the outset of this paper. Like others in the literature, many of these definitions highlight Berkeley's view that all bodies depend on minds, as well as his view that minds and bodies exist (he is not an eliminativist about bodies). The second conjunct of Strong Asymmetry and Existence capture these features of Berkeley's idealism. Second, the first conjunct of Strong Asymmetry expresses Berkeley's denial that it is possible that a mind depends on bodies.15 It is this component which rules out mindbody identity panpsychism and thus makes explicit what has been presupposed by Berkeley's commentators. The distinct advantage of our definition, relatedly, is that it clarifies where Berkeley would require further argument against a mind-body identity panpsychist rival. Third, note that it is not enough for Berkeley, as it is for many contemporary panpsychists, that the property of being mental or phenomenal properties exist ubiquitously and fundamentally. Strawson hints at this divide in his own definition of pure panpsychism, arguing "[that] the existence of subjects of experience can't be supposed to be anything ontologically over and above the existence of experiencing" (2016, 81). Rather, independent mental substances are a key part of Berkeley's ontology.16 15 God depends on nothing (other than Himself), and thus not on any body. Finite minds are more complicated, yet we think Berkeley holds that while there could be no finite minds independent of all ideas whatsoever, minds do not depend on the ideas that constitute bodies. Thus no minds depend on bodies. 16 We do not deny that Berkeley scholars debate his commitment to mental substance. For instance, Robert Muehlmann argues that "Berkeley's nominalism (and, consequently, his anti-abstractionism) is fatal to substances, whether material or mental" (1995, 90; see also Muehlmann 1992). Others, like Marc Hight and Walter Ott (2004), argue that Berkeley's conception of mental substance is relatively traditional and that for Berkeley mental substances are objects of inner awareness, or agents (on this latter point, see Bettcher 2008). Still others argue for a Stoic conception of substance not amenable to being spoken of or theorized abstractly, like Stephen Daniel (2001 and 2008). Despite this disagreement, we think on balance the texts strongly suggest Berkeley includes mental substances in his ontology. Graham Clay & Michael Rauschenbach Some forms of panpsychism, including Strawson's pure panpsychism and perhaps Chalmers' constitutive Russellian panpsychism, might count as forms of idealism in the sense defined, depending on the stance taken on whether microexperience requires micro-minds. But we agree with Segal and Goldschmidt (2017, 47) in counting this consequence among our view's advantages: the fundamentally idealist implications of some forms of contemporary panpsychism bear noting and should be accounted for by an adequate definition. At best, arguments like the inseparability argument support the second conjunct of Strong Asymmetry, while other arguments are needed for the other components of Berkeley's idealism. In the rest of the paper, we conclude with some thoughts about Berkeley's prospects for success with these tasks. 5. The Virtues of Unity Here, we conclude by surveying two Berkeleyan strategies, one more prominent in Berkeley's published writings than the other, for establishing the following claim: Non-Identity: Necessarily, for all x, if x is a body, then x is not a mind. Establishing this claim is a necessary first step if Berkeley is to secure the first conjunct of Strong Asymmetry. Non-Identity will be established if Berkeley establishes that, necessarily, for all x, if x is a mind, then x is F, where F is some quality, and, necessarily, for all x, if x is a body, then x is not F.17 All dialectically defensible methods for Berkeley to establish Non-Identity in the face of opposition from the mind-body identity panpsychist reduce to this schema. The mere stipulation or presumption of Non-Identity would be question-begging, and both direct and topical reductio arguments for NonIdentity would be instances of this schema. The first option to consider is that 'active' is F. After considering this possibility, we will suggest reasons for Berkeley to shift his emphasis to his less common proposal-namely, that minds are fundamentally unified in a way no bodies are or could be. We will conclude by briefly discussing Berkeley's prospects for establishing the rest of the claims he needs in order to secure the first conjunct of Strong Asymmetry and Mental Substances.18 Berkeley's focus on the activity of minds and the passivity of bodies is ubiquitous. When Philonous is first challenged by Hylas to explain how his "passive and inert" idea of a "purely active" being like God or himself could represent such a being, he has this to say: 17 Spinoza's views on identity and non-identity are highly idiosyncratic, but Spinoza can accept our method of establishing Non-Identity (though of course he rejects Non-Identity, since he thinks minds just are bodies), as long as the relevant F in our schema is what some commentators have called an "attribute-neutral property." And activity and unity, insofar as they are discussed explicitly at all by Spinoza, are clearly attribute-neutral. See Della Rocca 1999, Newlands 2018, and Melamed 2013 for more on Spinoza's use of attribute-neutrality. 18 We thus set aside the question of establishing Existence. Can the Berkeleyan Idealist Resist Spinozist Panpsychism? PHILONOUS. [...] I do nevertheless know that I, who am a spirit or thinking substance, exist as certainly as I know my ideas exist. Farther, I know what I mean by the terms 'I' and 'myself'; and I know this immediately, or intuitively, though I do not perceive it as I perceive a triangle, a color, or a sound. [...] (3D 231) PHILONOUS. How often must I repeat, that I know or am conscious of my own being; and that I myself am not my ideas, but somewhat else, a thinking active principle that perceives, knows, wills, and operates about ideas. [...] (3D 233) Assuming that Philonous' position can be identified with Berkeley's own, Berkeley's argument in this passage is an appeal to his intuitive or reflective awareness of himself-he knows that he exists as an active mental being "by a certain internal consciousness" (DM 21).19 Yet, it seems that Berkeley's awareness of himself could at most show that he is a mind and is active at the time that he introspects, but not that it is necessary that he is. How could experience teach Berkeley that it is not possible that he is passive? Cartesian memories loom large here. One solution is to interpret Berkeley as holding that 'active' refers to a capacity, such that if Berkeley is aware of himself as active, then he is aware of himself as capable of acting at all possible times that he exists.20 This syncs better with Philonous' claim that minds are passive when they perceive via the senses and also with Berkeley's remark to Samuel Johnson that "the soul of man is passive as well as active, I make no doubt" (Works 2:293). If there could be some duration when minds perceive only via the senses, then it seems Berkeley must deny that, necessarily, minds are acting, but he need not deny that necessarily, minds are capable of acting.21 To be clear, though, Berkeley does not maintain that minds are nothing over and above their activity (or capacity for activity). Berkeley locates the activity of the mind in the will, which is one of its two constituent faculties. Here is one of Berkeley's arguments which relies on this bipartite concept of the mind: PHILONOUS. [...] From the effects I see produced, I conclude there are actions; and because actions, volitions; and because there are volitions, there must be a will. Again, the things I perceive must have an existence, they or their archetypes, out of my mind: but being ideas, neither they nor their archetypes can exist otherwise than in an understanding: there is therefore an understanding. But will and understanding constitute in the strictest sense a mind or spirit. The powerful cause therefore of my ideas, is in strict propriety of speech a spirit. (3D 240) 19 For Berkeley, this "internal consciousness" is not mediated by ideas, which he makes clear in saying: "Our souls are not to be known in the same manner as senseless inactive objects, or by way of idea" (PHK 142) 20 For cases where Berkeley uses 'active' in this sense, see PHK 53 and PHK 61. 21 Note, however, that some interpreters argue that Berkeleyan sense perception is not passive, and that Berkeley conceives of sense perception in an adverbial manner as a series of mental acts. For a classic defense of this interpretation, see Pitcher 1969. For a recent defense of a similar view, see Frankel 2013. For an extended criticism of views of this kind, see Marušić 2018. Graham Clay & Michael Rauschenbach In a similar fashion, Berkeley occasionally argues for the passivity of bodies via conceptual analysis. For instance, in De Motu 22, Berkeley argues that the qualities distinctive of bodies exclude power when he proposes that [...] impenetrability, extension, or shape include or connote no power to produce motion. On the contrary, when we review one by one not only those qualities but whatever other qualities that bodies possess, we see that they are all genuinely passive, and that there is nothing active in them [...]. But Berkeley's more common strategy is to identify bodies with ideas in order to argue for bodies' passivity via the passivity of ideas. If ideas are "visibly inactive," as Berkeley argues at Principles 25, then Berkeley can rightfully conclude that they are in fact inactive, given his view that "there is nothing in them but what is perceived." There is some disagreement about the next step. Some commentators argue that Berkeley identifies bodies one-to-one with the ideas of one sensory modality, others argue that Berkeley identifies bodies with collections of ideas perceived via multiple sensory modalities across time (including, perhaps, some that will be or would be observed), and still others fall somewhere in between these extremes. It is granted on all hands, though, that Berkeley identifies bodies with ideas or collections of ideas. Berkeley argues for this identification at various points in his corpus by arguing for the identification of bodies with whatever it is we "immediately perceive by our Senses" (3D 180) since ideas are what we immediately perceive. If Berkeley is correct that bodies are necessarily inactive, perhaps because they are ideas and ideas are "visibly" so, or because the concept of body excludes power, then he is well on his way to Non-Identity. In four interconnected ways, Spinoza challenges Berkeley's reliance on 'active' as the quality F that differentiates minds from bodies. First, whereas Berkeley thinks that there is nothing in ideas but what is perceived, Spinoza argues that our ideas of bodies-and what they are capable of-are fundamentally inadequate: "For indeed no one has yet determined what the body can do, that is, experience has not yet taught anyone what the bodies can do from the laws of Nature alone" (EIIIp2s).22 Second, granting for the moment that Berkeley is right that there is nothing in ideas but what is perceived, and that bodies are ideas, Berkeley would still need to establish that our mind is not an idea or collection of ideas to establish Non-Identity. Berkeley must do so without simply presupposing that ideas, or bodies, are perceived as "visibly inactive." Spinoza is not alone in failing to share that perception and, as noted before, he has arguments to establish that our minds are ideas. 22 An anonymous reviewer points out that Spinoza argues that those aspects of bodies which meet two criteria, namely that they are "common to all, and which are equally in the part and the whole" (EIIp38dem) must necessarily be adequately conceived. This might seem to complicate our claim that, for Spinoza, our ideas of bodies are fundamentally inadequate. But we do not think this obviates Berkeley and Spinoza's disagreement. EIIp38dem entails that some aspect of every body, that which is common to all and equally in the part and the whole, must be adequately conceived, but it does not imply that any finite minds have adequate conceptions of finite bodies in total. And since Berkeley thinks that there is nothing in bodies, which are ideas or collections of ideas, but what is perceived, there are deep and wide-ranging disagreements about the adequacy of our conceptions of bodies between Spinoza and Berkeley, which is all our claim here requires. Can the Berkeleyan Idealist Resist Spinozist Panpsychism? Third, Spinoza argues that minds are only active when their associated bodies are: "Does not experience also teach that, if the body is inactive, the mind is at the same time incapable of thinking?" (EIIIp2s).23 Berkeley denies that a mind is, at any time, completely incapable of thinking, both for the reasons already discussed and because he maintains that the passage of time is relativized to a thinker's thoughts.24 But bodies, for Berkeley, are always wholly passive. Fourth, Spinoza argues that the essence of a finite thing, whether thinking or extended, is its degree of power, and thus bodies, like minds, are inherently powerful and active.25 For all that we have said so far, one might think that Berkeley and Spinoza simply come to opposing conclusions on the basis of similarly compelling arguments. The mere existence of Spinoza's alternatives and their accompanying arguments, one might think, is not enough to put pressure on Berkeley's use of 'active' as the F needed to establish his idealism at the expense of mind-body identity panpsychism. Yet, another feature of Spinoza's defense of his mind-body identity panpsychism puts special pressure on Berkeley in particular and reveals a strategy Berkeley might use to try to avoid Spinoza's challenge to his view. Spinoza argues for his substance monism on fairly traditional grounds, using versions of the ontological and cosmological arguments for God's existence.26 Berkeley, as an Anglican Christian bishop, faces significant theological pressure to accept these traditional arguments.27 Michael Della Rocca, for example, interprets Spinoza's argument as containing four key steps: 23 Note that Spinoza also rejects the view that either the mind or body could ever be completely inactive. Spinoza's point here must thus be read as suggesting that the activity levels of the body and the mind are, in our experience, precisely correlated, contrary to Berkeley's suggestion that the mind is often quite active while its ideas, bodies, are wholly passive. Berkeley cannot challenge Spinoza's claim here by appealing, for example, to cases where people who are paralyzed still think. This is not a true mismatch in the activity levels of mind and body, of course, since "bodies" for Spinoza include any physical extended thing of whatever size. What would be needed for a Berkeleyan counterexample like this to succeed would be mental activity in the complete absence of neural (that is, bodily) activity, and such cases do not exist in our experience. 24 For instance, in his letters to Samuel Johnson, Berkeley states that "A succession of ideas I take to constitute Time, and not to be only the sensible measure thereof, as Mr. Locke and others think" (Works 2:293). There, Berkeley also rules out one mind's succession of ideas being a measure of the time of another, and he argues that "all things, past and to come, arc actually present to the mind of God, and that there is in Him no change, variation, or succession" (Works 2: 293). 25 See, for example, EIp36, EIIIp7, EIVdef8, and elsewhere. Della Rocca (2003, 225) discusses these and related passages. 26 Of course, we do not mean to imply either that Spinoza's God just is the Christian God or that his versions of the ontological and cosmological argument are identical to traditional Christian ones. Indeed, it is clear that Spinoza's God is not the Christian God, for reasons we have already identified, first and foremost among which is that the Christian God is in no way material or extended. For commentators who argue that, nonetheless, Spinoza's arguments mirror ontological or cosmological arguments in many particulars, see Garrett 1979, Earle 1951, Jarrett 1976, and Laerke 2011. 27 This is a sociological claim quite independent of Berkeley's other disagreements with Spinoza, which one might reject depending on how closely one associates Berkeley's philosophical and religious commitments. Regardless, it is obviously better from a strategic point of view if Berkeley could press his objections to Spinozism without being forced to reject orthodox Christian theology, even if Berkeley's preferred arguments for the existence of God are rather different, or at least presented as such. Graham Clay & Michael Rauschenbach Spinoza argues first that no two substances can share an attribute (1p5). Second Spinoza argues that "it pertains to the nature of a substance to exist" (1p7). On the basis of 1p7, Spinoza argues that God-defined as the substance with all the attributes-exists. Finally, since God exists and has all the attributes and since there can, by 1p5, be no sharing of attributes, no other substance besides God can exist. Any such substance would have to share attributes with God and such sharing is ruled out. (Della Rocca 2008, 46) On this reconstruction, and given some sociological pressure to accept the traditional theological arguments, Berkeley's ideal strategy would be to combat EIp5, which is the view that no two substances (i.e. finite minds and God, for Berkeley) share an attribute. But as far as we can tell, Berkeley never sees, and therefore never addresses, the problem of whether there can be multiple substances of the same attribute. Other interpreters, like Don Garrett, disagree with Della Rocca about how exactly to formulate the strongest version of Spinoza's reasoning, but they agree that it shares some features with the traditional ontological argument while ultimately relying on a very strong Principle of Sufficient Reason more at home in standard versions of the cosmological argument.28 There is a consensus, however, that Spinoza's mind-body identity panpsychism follows quite directly from his theology. Spinoza's arguments for his so-called "parallelism doctrine" (EIIp7) that "the order and connection of ideas is the same as the order and connection of things," and for his mind-body identity panpsychism (EIIp7s), that "a mode of extension and an idea of that mode are one and the same thing," cite only EIA4, which states that "knowledge of effects depends on, and involves, knowledge of causes." Immediately prior to introducing his mind-body identity claim, Spinoza says, "[b]efore we proceed further, we must recall here what we showed in the First Part." Yitzhak Melamed relies on this language to argue that Spinoza's mind-body identity panpsychism follows from the nature of God alone, as already proved in EIp16: "From the necessity of the divine nature there must follow infinitely many things in infinitely many modes." That is, for Melamed, Spinoza's doubling of infinity (infinite things or modes of God...in infinitely many ways or modes) is already sufficient to establish mind-body identity panpsychism, since each "mind and body are just two out of the infinite aspects of a mode of God which follows from God's nature" (2013, 648-649; see also our footnote 7 above). Della Rocca (2008, 89-136) draws a linear connection between Spinoza's substance monism, the constraints of the Principle of Sufficient Reason, and mind-body identity panpsychism. In broad strokes at least, Garrett seems to agree, noting that [Spinoza] will reply that the perfection of the necessarily existing divine substance, as established by the ontological argument and the principle of sufficient reason, actually requires that one substance have all possible principal attributes, necessarily mirroring one another...this means that the one substance and each of the singular things that are its finite 28 Garrett 1979 marks the beginning of this fruitful debate, which Della Rocca continues (2002 and 2008) and Garrett returns to a decade later (2018b). Can the Berkeleyan Idealist Resist Spinozist Panpsychism? modes must exist in multiple fundamentally different yet complementary dimensions of being-including as thinking and as extended. This is nothing less than panpsychism. (Garrett 2018a, 237-238) So, Spinoza sees mind-body identity panpsychism as following rather directly from his conception of the divine nature-a conception that leaves little room for the appeals to the will that form one prong of Berkeley's conception of spirits as active. In fact, Spinoza would challenge every step of Philonous' aforementioned argument in Dialogues 240 that "From the effects I see produced, I conclude there are actions; and because actions, volitions; and because there are volitions, there must be a will." Spinoza agrees that every effect implies some activity, but he would argue that the inferences from activity to actions and from actions to volitions are not warranted. And Spinoza argues in EIIp48-49 that since each mind is a determinate mode of God (EIIp11), and since all God's determinate modes are necessarily caused by preceding ones (EIp28), there are no free acts of will, but only effects produced by necessity, such that "in the mind there is no other volition, or affirmation or negation, except that which the idea involves insofar as it is an idea" (EIIp49).29 In this way, Spinoza argues from God's nature to a mind-body identity panpsychism in which volitions just are ideas, the complex joining of which is all there is to being a mind. Space does not permit us to fully evaluate each step of Spinoza's reasoning. We can grant that it is unclear whether Berkeley would accept the Principle of Sufficient Reason. And Berkeley would certainly continue to deny that Extension is a possible attribute of substance. Nonetheless, the more or less traditional theological arguments whose conclusions Spinoza interprets in heterodox ways to ground his mind-body panpsychism pressure Berkeley to justify his rejection of that position (and its entailment that minds and bodies are active to precisely the same extent). The burden is on Berkeley to explain how his arguments for the passivity of bodies remain compatible with these traditional theological arguments. Berkeley could go this route and address Spinoza's arguments directly, showing in detail how Spinoza goes wrong in the above-noted ways. Perhaps Berkeley has some fairly direct way of challenging Spinoza's claim, in EIp5, that no two substances can share a single attribute, which we have simply overlooked. But it is our position that a simpler and more dialectically effective solution would be for Berkeley to switch his emphasis from the mind's activity to the mind's unity, following Leibniz's example.30 Like Berkeley, Leibniz focuses at times on the activity of substances, which for 29 See Garrett 2000, Curley and Walski 1999, and Newlands 2018, Ch. 4, for more discussion of Spinoza's commitment to necessitarianism. Della Rocca 2003 gives much more of the argument for Spinoza's rejection of the distinction between will and intellect, or willing and the having of an idea. 30 An anonymous reviewer suggests that Berkeley's commitment to the semiotic structure of ideas in An Essay Towards a New Theory of Vision and Alciphron, Dialogue 4 might serve as an alternative route to establish an asymmetry between minds and ideas. Perhaps we can infer such an asymmetry from asymmetries between signs and language creators. John Roberts (2007, 90n14) seems to hint at something similar in connecting Berkeley's views on the difference between minds and ideas to his overall philosophy of language, and Kenneth Pearce's Language and the Structure of Berkeley's World (2017) is a powerful new discussion of Berkeley's thought that serves in many ways as a general development of this line of argument. Although space does not permit us to discuss it with the detail it deserves here, Graham Clay & Michael Rauschenbach him include only minds, and at other times on their unity. For instance, in the Monadology, Leibniz is clearly focused on the unity of mental substances. This is evident both from his opening definition- "the monad, which we shall discuss here, is nothing but a simple substance that enters into composites"-and from his famous "mill argument" in Monadology 17, which seeks to show that "perception, and what depends on it, is inexplicable in terms of mechanical reasons," such that "we should seek perception in the simple substance and not in the composite or in the machine." Why would this shift in emphasis help Berkeley? For one, it would block many of Spinoza's objections to the use of 'active' as F that we started with. Second, accounting for certain aspects of the unity of minds is widely regarded as one of panpsychism's most important challenges. One popular formulation of the combination problem for panpsychism holds that subjects, or subjective perspectives, cannot unite. If we as subjects and our thoughts as constituting a particular perspective have the unity that Berkeley argues they do and that we commonly take them to have, they cannot be constituted as the mind-body identity panpsychist says they are.31 Third, Spinoza accepts the mutual dependence of minds and bodies, in our weak sense, in virtue of their identity. But he explicitly denies the finite mind's unity, in part because he holds that the finite mind is identical to a finite body that is composite.32 If either our concepts, the data of experience, reasoning along the lines of Leibniz's mill argument, Kant's argument for the transcendental unity of apperception, or some other arguments favor Berkeley here, then Berkeley will have an advantage over Spinoza. This is not to claim that there are no complications facing Berkeley were he to change his approach. One issue is that Berkeley never gives us a full account of the relevant sort of unity-it may be that this part of his system was lost when the rest of the Principles were lost.33 Another is that Berkeley seems to maintain that the unity of the mind follows from its activity. Berkeley often mentions activity and unity simultaneously as features of minds (though he almost invariably focuses on activity at the expense of unity).34 Some commentators interpret Berkeley (or, at least, the "mature Berkeley") as understanding perception as requiring an active mind to gather together the objects of we have some preliminary comments on this strategy. On one hand, it seems that the property F that this line of reasoning attributes to language creators would be activity or unity (i.e. language creators are active with respect to signs that constitute language or language creators unify signs into words or sentences, while the signs and the ideas they signify are passive or require unification), or a property that entails the former or the latter. Insofar as F is the former, the concerns we discuss would still apply, while insofar as it is the latter, there may be significant promise to this strategy given the relative scarcity of texts where Berkeley discusses unity explicitly (as we note below). On the other hand, an argument to the mind's unity that does not require the adoption of significant parts of Berkeley's philosophy of language would be preferable. 31 See, among others, Chalmers 2016b, 182-183, as well as Montero 2016, and others in the same volume, for discussion of this aspect of the combination problem. 32 "The idea that constitutes the formal being of the human mind is not simple, but is composed of a great many ideas" (EIIp15). Here, as always, we mean only minimal dependence with respect to existence in describing Spinoza's view. 33 As A.A. Luce and T.E. Jessop surmise in their Editor's Introduction to Berkeley's letters to Samuel Johnson. See Works 2:269. But see footnote 30 for one suggestion of how an account of unity may be present in Berkeley's texts in the form of his philosophy of language. 34 See, for example, Principles 141 or Dialogues 234 and 249. For a discussion of unity's importance to Berkeley's view of substances (and its origins in his philosophical antecedents), see Wilson 1995, 81-88. Can the Berkeleyan Idealist Resist Spinozist Panpsychism? perception into a single unified perspective à la Kant.35 Others suggest that the distinctive activity of minds is to imitate God, such that "to fully and properly achieve participation in the divine nature, it is not enough to grasp clearly and distinctly what I ought to do-I must act on that knowledge [...] to be engaged in the activity of virtue [is our] proper, natural state" (Roberts 2018, 150).36 If either view is right, then even though one of the mind's specific activities explains and is thus more fundamental than its unity, Berkeley could simply argue that bodies lack this type of activity-the ability to unify perceptions in a single perspective, on the former reading, or to act as a unified virtuous agent, on the latter. Berkeley need not necessarily commit himself to showing that bodies are wholly passive, just that they are passive with respect to a certain type of activity, even if the latter is something he in fact continues to believe. A third complication is that Berkeley also mentions unity as a feature of collections or "congeries" of ideas but also as a feature of individual ideas like sensations. Below is an example of the latter: HYLAS. Hold, Philonous, I fear I was out in yielding intense heat to be a pain. It should seem rather, that pain is something distinct from heat, and the consequence or effect of it. PHILONOUS. Upon putting your hand near the fire, do you perceive one simple uniform sensation, or two distinct sensations? HYLAS. But one simple sensation. PHILONOUS. Is not the heat immediately perceived? HYLAS. It is. PHILONOUS. And the pain? HYLAS. True. PHILONOUS. Seeing therefore they are both immediately perceived at the same time, and the fire affects you only with one simple, or uncompounded idea, it follows that this same simple idea is both the intense heat immediately perceived, and the pain; and consequently, 35 This activity does not, however, require precedent volitions, so it is not the same sort of agency as is involved with the will (and so it can be, and is, blind). See Hill 2018. If, for Berkeley, activity and unity are in fact linked in this way, such that the relevant sort of unity is entailed by activity, then activity would be an appropriate F, as it would be sufficient to establish Non-Identity. However, displaying this fact would require an argument for the link between activity and unity, as well as an expanded version of the argument we have given for the efficacy of unity against the mind-body identity panpsychist. 36 Later in Roberts' discussion of Cudworth's Neo-Platonism and its connection to Berkeley's view, he draws, implicitly and without much commentary, as Berkeley often does, the same connection between activity and unity or simplicity, saying: "His is a view of agents as simple, active, immaterial substances where activity is conceived of exactly the way it should be if we are made in the image of God and God's nature is conceived of axiarchically. In other words, where activity is conceived of as volition. It is through volition that our moral natures are self-determined" (2018, 152; italics ours). Graham Clay & Michael Rauschenbach that the intense heat immediately perceived, is nothing distinct from a particular sort of pain. (3D 176) If Berkeley is to establish per our proposed definition that, necessarily, for all x, if x is unified, then x is a substance, then he must distinguish between different kinds of unity. As for collections or congeries of ideas, Berkeley holds that "in each instance it is plain, the unit relates to some particular combination of ideas arbitrarily put together by the mind" (PHK 12).37 Since the unity of minds explains the unity of collections and congeries in this way, its unity must be distinct from and more fundamental than theirs.38 Even if the sort of unity possessed by a mind which enables it to unify collections and congeries is its unity of perspective, more needs to be said about what this amounts to.39 Supposing Berkeley were to have a well-developed account of what this unity of perspective amounts to, he would be in a much improved position relative to panpsychists more generally and mind-body identity panpsychists like Spinoza in particular. Although Berkeley's texts provide little immediate assistance in further explicating his account of the mind's unity, Berkeley could rely on plausible arguments defended by others to improve his position. The benefits are significant not only because they provide additional grist for Berkeley's idealist mill, but also because the claim that the mind is unified-while the body is not-has substantially greater intuitive plausibility than the claim that since bodies are ideas and ideas are passive, bodies are wholly passive. This advantage in intuitive plausibility remains so even if Berkeley's ultimate explanation for the mind's unity is its having a specific sort of activity, as unifier of perceptions into a single perspective or as unified virtuous agent, that bodies lack. 37 See also 3D 245-246 and 3D 249. 38 There is robust discussion in the literature of "Berkeley's dualism," which is roughly the view that minds and ideas have "natures perfectly disagreeing" (PHK 139), beginning with Berman 1994, 21-22, Roberts 2007, 90, 90n14, Bettcher 2007, 51-53, and Hill 2018, 127. For our purposes, though, these discussions bring together many questions we prefer to discuss separately. For instance, Roberts (2007, 90n14) discusses Berkeley's dualism in connection with his philosophy of language, which we do not consider here, except briefly in footnote 30. By contrast, Hill (2018, 127) connects Berkeley's dualism to the passivity of ideas, as we discuss here and in what follows, and Bettcher's fascinating discussion (2007, 51-53) touches on ideas' passivity, but also on Berkeley's rejection of ideas as "modifications of the mind" (52) and on self-knowledge generally. We respond to the passivity points in the main text, but Bettcher's point about ideas as modifications deserves special comment. Notably, however effective Berkeley's arguments are against this Cartesian view, Spinoza's view is different. Ideas are not modifications but constituents of the mind; said differently, the mind is a complex idea. Of course, Berkeley also rejects the notion that minds are complex, and indeed, as we discuss in our section on unity, we think this is his most promising strategy. But we do not think the most promising version of Berkeley's argument runs through the passivity of ideas (and thus their non-identity with minds), but rather through the unity of spirits (and thus their non-identity with Spinoza's complex ideas). 39 Especially since Berkeley claims that the unity of minds entails that they are "incorruptible," "indissoluble by the Force of Nature," and "immortal" (PHK 141). A simple pain is, by contrast, corruptible, dissoluble, and mortal, and undeniably so. Berkeley does not give a clear explanation of what explains the difference. Can the Berkeleyan Idealist Resist Spinozist Panpsychism? 6. Conclusion The foregoing suggests that, even if Berkeley fails to identify mind-body identity panpsychism as an important rival to his idealism, he may in the end have the resources to argue for Non-Identity. We are optimistic about Berkeley's chances, although pessimism looms. If neither 'unified' nor 'active' are viable replacements of F in our schema, and so neither enable Berkeley to defend his idealism, then what follows is that his idealism is simply ill-suited to respond to the challenge posed by mind-body identity panpsychism, given the significant limitations of Berkeley's arguments for his position we have identified here. Supposing, though, that Berkeley can establish Non-Identity, he then must turn to the other components of his idealism. Mental Substances can be secured if Berkeley can establish that, necessarily, for all x, if x is unified, then x is a substance. It follows from this claim and the claim that, necessarily, for all x, if x is a mind, then x is unified that, necessarily, for all x, if x is a mind, then x is a substance. Since, again, it is not clear what sort of unity all minds possess on Berkeley's view, we cannot address whether Berkeley could plausibly argue that only substances have this sort of unity. There is reason, however, to be hopeful about this possibility, given that whatever sort of unity it is, it is not possessed by ideas, which are, on Berkeley's picture, the only non-substances. With NonIdentity and Mental Substances in hand, Berkeley can establish the first conjunct of Strong Asymmetry with the addition of only one further claim: necessarily, x is a substance if, and only if, x is independent. This is an eminently plausible claim since substances are generally defined as independent beings, both in the early modern context and otherwise. Supposing Berkeley is successful at these tasks, he would have his idealism, or something near enough.40 Primary Texts PHK Berkeley, G. 1710. Of the Principles of Human Knowledge: Part 1. Luce/Jessop (eds.) 1948-1957. London: Thomas Nelson and Sons. 3D Berkeley, G. 1713. Three Dialogues between Hylas and Philonous. Luce/Jessop (eds.) 1948-1957. London: Thomas Nelson and Sons. DM Berkeley, G. 1721. 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