Unperceived Existence and Hume's Theory of Ideas JONATHAN COTTRELL Forthcoming in Oxford Studies in Early Modern Philosophy, vol. 9. §1 AN INCONSISTENT TRIAD? Hume seems committed to an inconsistent triad. In the Treatise section 'Of scepticism with regard to the senses', he claims to explain 'the causes which induce us to believe in the existence of body' (T 1.4.2.2/187–88).1 This presupposes that we have such a belief. According to Hume, believing in body involves believing in things with 'CONTINU'D' and 'DISTINCT' existence, i.e. that continue to exist 'even when they are not present to the senses' or 'even when they are not perceiv'd' (continued existence), and that exist and operate 'independent[ly] of the mind and perception' in a location outside the mind (distinct existence) (T 1.4.2.2/188). Hume's view that we believe in things with continued existence, in particular, seems to commit him to: BELIEF We believe certain things to exist unperceived. Earlier in the Treatise, Hume seems to argue that a belief is 'A LIVELY IDEA' 2-that is, an idea with more 'force and vivacity' than those we form when merely thinking of something without believing in it (T 1.3.7.5–6/96–97). In his example, the belief that God exists is a lively idea that represents God as existing (T 1.3.7.2/94–95). This is an existential belief, but Hume indicates that his account applies to predicative belief as well: for example, to belief in the (false) propositions 2 'that Caesar dy'd in his bed, that silver is more fusible than lead, or mercury heavier than gold' (T 1.3.7.3/95). So, he seems to hold that, in general, believing a thing to exist or to have a certain property is having a lively idea that represents that thing as existing or as having that property. Some scholars deny that we should interpret Hume as identifying beliefs with lively ideas. For example, Louis Loeb argues that we make best overall sense of the Treatise if we interpret Hume as holding instead that beliefs are steady dispositions.3 However, Loeb allows that having lively ideas, including ideas that represent what one believes, is a characteristic manifestation of a dispositional belief.4 On this view, then, a belief that a certain thing exists or has a certain property is a disposition whose characteristic manifestations include having an idea that represents that thing as existing or as having that property. In order to have this disposition, we must have such an idea (let us say) at our disposal: that is, from the simple ideas available to us, we must be able to assemble an idea that represents what we believe. So, whether Hume holds that a belief is a lively idea that represents what one believes or a steady disposition as described by Loeb, he seems committed to: BELIEF®IDEA If we believe a certain thing to exist unperceived, then we have (at our disposal) an idea that represents it as existing unperceived. Taken together, BELIEF and BELIEF®IDEA imply that we have (at our disposal) ideas that represent certain things as existing unperceived. But numerous scholars say that this conflicts with Hume's theory of ideas-in particular, with his Copy Principle, 'that all our simple ideas in their first appearance are deriv'd from simple impressions, which are correspondent to them, and which 3 they exactly represent' (T 1.1.1.7/4). According to these scholars, the Copy Principle implies that we can form an idea of unperceived existence only if we have encountered this property by way of our senses, so as to receive an impression of it; but we cannot have done so, because perceiving an object by our senses deprives it of this property; so, we cannot form an idea of unperceived existence; and so, we cannot form an idea that represents anything as existing unperceived.5 In light of this, Hume seems committed to: NO IDEA We do not have (at our disposal) an idea that represents anything as existing unperceived. So, Hume seems committed to the inconsistent triad of BELIEF, BELIEF®IDEA, and NO IDEA. I aim to acquit him of this charge by showing that he is not, in fact, committed to NO IDEA. On the contrary, his theory of ideas allows that we can form ideas that represent certain things as existing unperceived. I proceed as follows. In recent publications, Donald Ainslie, Annemarie Butler and Kenneth Winkler have denied or questioned whether Hume is committed to BELIEF. §2 argues that he is. The following sections focus on NO IDEA. Some scholars claim that Hume explicitly argues for this proposition. §3 argues that the textual evidence they present is unconvincing. These scholars might reply that, whether or not Hume explicitly argues for NO IDEA, he is implicitly committed to it by his Copy Principle. §4 considers the three most plausible interpretations of the Copy Principle and argues that none of them commits him to NO IDEA. My opponents might reply that Hume is committed to NO IDEA by the Copy Principle together with his view that all simple impressions are of positive qualities such as colors, sounds or tastes 4 (T 1.1.6.1/15–16).6 These commitments, they might say, jointly imply that no idea represents any negative property, hence that no idea represents anything as existing unperceived (that is, as existing and not being perceived). This argument raises the more general issue of whether Hume can satisfactorily account for negation-an issue raised in his own lifetime by Thomas Reid and more recently by Barry Stroud and others. In §5, I offer Hume an account of negation modeled on his accounts of the ideas of substances and modes (T 1.1.6) and abstract ideas (T 1.1.7). I also draw on his account of perceiving, which says that being perceived is bearing a distinctive causal relation to a mind (T 1.4.2.40/207–8). I argue that, by combining these accounts, Hume can consistently explain how an idea represents something as existing unperceived-that is, as existing and not bearing this distinctive causal relation to any mind. If successful, this argument shows that he is not committed to NO IDEA. In §6, I compare the account of negation developed in §5 with alternative accounts that other scholars have recently offered to Hume. Lastly, §7 addresses an objection. Some scholars claim that Hume regards non-human animals as sharing our belief in body. If they are correct, then he could not consistently accept my account of negation, which does not apply to non-human animals' ideas. I reply that there is no clear textual evidence for these scholars' claim about non-human animals. Two caveats before I proceed: First, 'Of scepticism with regard to the senses' distinguishes two forms of belief in body, 'vulgar' (or ordinary) and 'philosophical' (T 1.4.2.14/193, 1.4.2.31/202). Philosophers at least purport to believe in 'objects' or bodies that are distinct from their perceptions (T 1.4.2.46/211). In contrast, the 'vulgar'-which includes 'all of us, at one time or other' (T 1.4.2.36/205)-'confound perceptions and objects, and attribute a distinct continu'd existence to the very things they feel or see' (T 1.4.2.14/193); the 'very sensations, which enter by the eye or ear, are with them the true objects' (T 1.4.2.31/202). That is, the 'vulgar' attribute 5 continued and distinct existence to things that are, in fact, perceptions-specifically, impressions of sensation. Henceforth, I will set aside the 'philosophical' form of belief in body and focus entirely on the 'vulgar' one. Accordingly, §5 aims to show only that Hume can account for ideas that represent what are, in fact, perceptions as existing unperceived-hence, that represent what we 'vulgarly' believe.7 Second, when explaining our 'vulgar' belief in bodies' continued existence, Hume focuses on what causes us to form 'the supposition or idea of continu'd existence' (T 1.4.2.24/199) and on how this idea is enlivened so that it becomes a belief.8 His complicated account of the imaginative mechanisms responsible for this process is well known and much discussed.9 This account will not be my focus here. The question that primarily concerns me is not 'What mechanisms produce our idea of the unperceived existence of certain perceptions?', but 'How can any idea manage to represent anything as existing unperceived?'. Hume does not explicitly address this question.10 I aim to show that he can answer it satisfactorily. It is a further question whether the imaginative mechanisms described in 'Of scepticism with regard to the senses' could produce such an idea. I will not address this because it is not necessary for acquitting Hume of the inconsistent triad above. (Of course, if the answer to this further question is no, he may be guilty of a different inconsistency.) §2 IS HUME COMMITTED TO BELIEF? Hume writes that, insofar as we are 'vulgar' or ordinary people, we 'not only feign but believe this continu'd existence' (T 1.4.2.41/208) and that we 'believe the continu'd existence of body' (T 1.4.2.42/209). For Hume, to 'believe the continu'd existence of body' is to 'attribute a CONTINU'D existence to objects, even when they are not present to the senses' or 'even when they are not 6 perceiv'd' (T 1.4.2.2/188); insofar as we are 'vulgar', of course, the 'objects' in question are perceptions (T 1.4.2.14/193, 1.4.2.31/202, 1.4.2.36/205). So, he seems committed to: BELIEF We believe certain things to exist unperceived. But some scholars deny or question this. In recent publications, Donald Ainslie, Annemarie Butler, and Kenneth Winkler argue that the clauses 'even when they are not present to the senses' and 'even when they are not perceiv'd' do not specify what we vulgarly believe about bodies, but merely when we believe it. Suppose, with Hume, that I shut my eyes, thus momentarily ceasing to have impressions of the furniture around me, and then reopen them (T 1.4.2.35/204). According to these scholars, I do not believe that the furniture exists when it is unperceived; rather, when the furniture is unperceived, I believe that it exists.11 (For variations on this theme, see Ainslie 2015: 47–56, Butler 2010: 244, and Winkler 2015: 161–62, n11.) Contrary to BELIEF, then, we do not believe certain things to exist unperceived; we merely believe them to exist. For Butler, this interpretation is motivated partly by the need to acquit Hume of inconsistency with NO IDEA and BELIEF®IDEA.12 This interpretation fits some of Hume's descriptions of our 'vulgar' belief in continued existence. For example, when he writes that 'we attribute a CONTINU'D existence to objects, when they are not present to the senses' (T 1.4.2.2/188) and that we have a 'notion of the continu'd existence of . . . objects, after they no longer appear to the senses' (T 1.4.2.3/188), he may mean that, even after we stop perceiving objects, we continue to believe that they exist. But I have two objections to this interpretation. First, it cannot make sense of every passage about our 'vulgar' 7 belief in continued existence. Second, even if it could somehow accommodate these passages, it cannot accommodate certain passages about distinct existence and its relation to continued existence. I will explain these objections in turn. First, some passages indicate that our 'vulgar' belief in continued existence is a belief that certain things exist unperceived. For example, Hume writes that, when we hear 'a noise as of a door turning upon its hinges,' we 'suppose that the door still remains, and that it was opened without [our] perceiving it' (T 1.4.2.20/196–97). Here, the clause 'that it was opened without [our] perceiving it' specifies part of what we suppose about the door, not merely the time when we suppose it. Later, Hume raises a challenge to his account of our 'vulgar' belief in continued existence: how can we 'satisfy ourselves in supposing a perception to be absent from the mind without being annihilated' (T 1.4.2.38/207)? Here, again, 'to be absent from the mind' specifies what we vulgarly suppose about our perceptions, not the time when we suppose it. Hume answers the challenge by arguing that the 'supposition of the continu'd existence of sensible objects or perceptions involves no contradiction' (T 1.4.2.40/208) because 'there is no absurdity in separating any particular perception from the mind' (T 1.4.2.39/207). This argument presupposes that our 'vulgar' supposition of continued existence represents certain perceptions as existing separate from the mind. Again, 'separat[e] . . . from the mind' is part of what we vulgarly believe about our perceptions, insofar as we believe this supposition. Some scholars may reply that, in 'Of scepticism with regard to the senses' and elsewhere, Hume posits 'suppositions' that are not ideas, hence not beliefs.13 But he is clear that this 'vulgar' supposition, at least, is both an idea and a belief: when introducing and summarizing his discussion of it, which includes the passages just quoted from T 1.4.2.38–40, he calls it '[t]his supposition, or idea of continu'd existence' and claims that it is enlivened, so as to become a belief (T 8 1.4.2.24/199). Later, he writes that any imaginative propensity that gives rise to belief must 'convey the vivacity from the impression to the idea' and adds that 'this is exactly the present case' (T 1.4.2.42/208). So, it is implausible to deny that he regards the 'vulgar' supposition of continued existence as an idea. Second, the interpretation on which Hume does not hold BELIEF cannot accommodate certain passages about distinct existence and its relation to continued existence. In Hume's view, the imaginative mechanisms that produce our 'vulgar' belief in body work by first producing a belief in perceptions' continued existence, which then gives rise to a belief in their distinct existence: 'the opinion of the continu'd existence of body ... is prior to that of its distinct existence, and produces that latter principle' (T 1.4.2.23/199; here, he calls these opinions or beliefs 'principles'). He explains that we acquire the latter belief by inferring the distinct existence of certain perceptions from their continued existence, as 'a necessary consequence': I have already observ'd, that there is an intimate connexion betwixt those two principles, of a continu'd and of a distinct or independent existence, and that we no sooner establish the one than the other follows, as a necessary consequence. (T 1.4.2.44/210) Hume had 'already observ'd' the 'intimate connexion' between continued and distinct existence in this earlier passage: These two questions concerning the continued and distinct existence of body are intimately connected together. For if the objects of our senses continue to exist, even when they are not perceiv'd, their existence is of course independent of and distinct from the perception; and vice 9 versa, if their existence be independent of the perception and distinct from it, they must continue to exist, even tho' they be not perceiv'd. (T 1.4.2.2/188)14 So, the content of our belief in perceptions' continued existence must imply that of our belief in their distinct existence: otherwise, we could not infer the latter from the former 'as a necessary consequence.' A criterion for success, when interpreting 'Of scepticism with regard to the senses', is to accommodate this logical relationship between continued and distinct existence. Among those who deny that Hume's account of the 'vulgar' commits him to BELIEF, only Ainslie considers distinct existence and its relationship to continued existence. He argues that, for Hume, our 'vulgar' beliefs in continued and distinct existence are as follows: (Cn) The belief, of an object (say, a table) that has been sensed but is not currently being sensed, that it (the table) exists. (Dn) The belief, of an object (the table) that is currently being sensed, that it (the table) exists. Ainslie claims that this interpretation allows him to accommodate the logical relationship that Hume sees between continued and distinct existence (HTS, 52). But this claim is incorrect. Ainslie's (Cn) and (Dn) refer to different moments in time: (Cn), to moments when an object is not being sensed; (Dn), to moments when it is. In Hume's view, there is no necessary connection between an object's existence at one moment and its existence at any other.15 So, the content of (Cn) does not imply that of (Dn); in Hume's terms, we cannot infer (Dn) from (Cn) 'as a necessary consequence'. 10 Moreover, Ainslie's construal of our 'vulgar' belief in distinct existence as (Dn) is textually implausible. Hume writes that, when we 'believe in the existence of body', we 'suppose [objects] to have an existence DISTINCT from the mind and perception' (T 1.4.2.2/188). This indicates that distinct existence is part of what we suppose: we 'suppose [objects] to have' such an existence. Hume explains that distinct existence involves 'existence ... independent of ... the perception' (T 1.4.2.2/188). Taken out of context, this is ambiguous: it may mean either existence independent of being perceived, or existence independent of perceptions-that is, of impressions and ideas. But the context disambiguates it: Hume writes that 'if the objects of our senses continue to exist, even when they are not perceiv'd, their existence is of course independent of and distinct from the perception' (T 1.4.2.2/188, italics added). This inference is valid only if 'independent of ... the perception' means independent of being perceived.16 So it seems that, for Hume, believing in distinct existence involves believing certain things to exist independently of being perceived-that is, to be capable of existing unperceived. Other passages provide further evidence for this. Hume writes that we are 'naturally led to regard the world as something real and durable' (T 1.4.2.20/197). He equates having a 'real and corporeal existence', or having 'reality', with having a distinct existence and, in particular, with existing independently of being perceived (T 1.4.2.9–10/191; see also T 1.4.4.5–6/227–28, where he equates 'real' qualities with those that are 'continu'd independent existences'). For Hume, then, that the world is 'real'-capable of existing unperceived-is part of what we believe (or, of how we regard the world as being), when we believe in distinct existence. Ainslie's (Dn) does not capture this. According to (Dn), the content of our belief in distinct existence is merely that it (the table) exists-not that it (the table) can exist unperceived. So, 11 Ainslie's interpretation does not satisfactorily accommodate Hume's account of what believing in distinct existence involves. In contrast, the interpretation I favor, on which Hume accepts BELIEF, can accommodate these passages about distinct existence and its relationship to continued existence. On this interpretation, believing in a table's continued existence involves believing that it exists unperceived. This does imply that it can exist unperceived: if the table exists unperceived, then it must be able to do so. So, my interpretation satisfies the criterion above: it accommodates the logical point that the content of our belief in perceptions' continued existence implies that of our belief in their distinct existence, so that we can infer the latter from the former 'as a necessary consequence'. Moreover, it allows me to give a textually more plausible construal of what believing in distinct existence involves: namely, believing certain things to be capable of existing unperceived. I conclude that Hume is committed to BELIEF. For reasons given in §1, there can be little doubt that he is also committed to BELIEF®IDEA. To acquit him of inconsistency, let us therefore turn to NO IDEA. The next three sections address arguments that Hume is committed to this proposition. I aim to show that these arguments fail and that Hume is not committed to NO IDEA. On the contrary, he can consistently account for ideas that represent things as existing unperceived. §3 DOES HUME EXPLICITLY ARGUE FOR NO IDEA? As formulated in the Treatise, Hume's Copy Principle states that 'all our simple ideas in their first appearance are deriv'd from simple impressions, which are correspondent to them, and which they exactly represent' (T 1.1.1.7/4). Numerous scholars claim that this commits Hume to: NO IDEA 12 We do not have (at our disposal) an idea that represents anything as existing unperceived. Some of these scholars claim that Hume explicitly argues from the Copy Principle to NO IDEA. In this section, I aim to show that their textual evidence for this is unconvincing. They might reply that, by accepting the Copy Principle, Hume implicitly commits himself to NO IDEA. In the next two sections, I address this reply. Two passages may be cited as evidence that Hume explicitly argues from the Copy Principle to NO IDEA. One, from the section 'Of the idea of existence, and of external existence' (T 1.2.6), reads: Now since nothing is ever present to the mind but perceptions, and since all ideas are deriv'd from something antecedently present to the mind; it follows, that 'tis impossible for us so much as to conceive or form an idea of any thing specifically different from ideas and impressions. Let us fix our attention out of ourselves as much as possible: Let us chace our imagination to the heavens, or to the utmost limits of the universe; we never really advance a step beyond ourselves, nor can conceive any kind of existence, but those perceptions, which have appear'd in that narrow compass. This is the universe of the imagination, nor have we any idea but what is there produc'd. (T 1.2.6.8/67–68) Here, it may be said, Hume reasons from a claim related to the Copy Principle-that 'all ideas are deriv'd from something antecedently present to the mind'-to NO IDEA.17 But this would be an interpretive mistake, as I shall now argue. 13 Two claims in the quoted passage might be thought to express, or otherwise commit Hume to, NO IDEA. First, he claims that it is 'impossible for us so much as to conceive or form an idea of any thing specifically different from ideas and impressions'. Elaborating upon this claim later in the passage, he writes that we cannot 'conceive any kind of existence, but those perceptions' (italics added). Presumably, then, by 'specifically different', he means different in kind or species. But the claim that an idea cannot represent anything different in kind or species from a perception does not, by itself, commit him to NO IDEA. My opponents may be assuming that Hume would also accept this further claim: an idea can represent something as existing unperceived only if it represents something different in kind or species from a perception. Taken together with his claim in the quoted passage, this would commit him to NO IDEA. But there is no textual evidence that Hume accepts the further claim. On the contrary, there is evidence he would reject it. I have argued that, in his view, the 'vulgar' believe certain impressions to exist unperceived (§2). Taken together with BELIEF®IDEA, this implies that the 'vulgar' have (at their disposal) ideas that represent these impressions as existing unperceived. These ideas represent only things of the same kind or species as perceptions, yet represent these things as existing unperceived, contrary to the further claim above. Second, Hume claims that, in thought, 'we never really advance a step beyond ourselves'. Here, it may be said, he denies that we can conceive of anything as existing outside our own minds ('beyond ourselves'), and thereby commits himself to NO IDEA.18 But he cannot consistently accept this claim, so interpreted. He argues elsewhere that a mind, as far as we can conceive it, is a 'system' of causally related perceptions (T 1.4.6.19/261).19 On this view, for a perception to exist within a mind is for it to be causally related to other perceptions in a suitable way (T 1.4.2.39– 40/207–8). Since we can conceive of anything as existing apart from any distinct thing (T 14 1.1.7.3/18), and causes are distinct from their effects, we can conceive of anything as lacking causes and effects (T 1.3.3.3/79–80). So, by conceiving a perception in this way, we can conceive of it as existing outside any mind (T 1.4.2.39/207). And so, when Hume writes that 'we never really advance a step beyond ourselves', he must not (if he is consistent) mean that we cannot conceive of anything as existing outside our own minds. Instead, I propose, he again means that we cannot conceive of anything different in kind from those that we encounter within our own minds. The final clauses of the sentence support this reading: 'we never really advance a step beyond ourselves, nor can conceive any kind of existence, but those perceptions, which have appear'd in that narrow compass' (italics added). In recent publications, Butler and Landy present another passage, which appears in the section 'Of scepticism with regard to the senses' (T 1.4.2), as evidence that Hume argues for NO IDEA:20 To begin with the senses, 'tis evident these faculties are incapable of giving us the notion of the continu'd existence of their objects, after they no longer appear to the senses. For that is a contradiction in terms, and supposes that the senses operate, even after they have ceas'd all manner of operation. (T 1.4.2.3/188) As Butler interprets it, this passage argues that we have no impression from which we could copy an idea that represents something as existing unperceived; therefore, by the Copy Principle, we have no such idea. Landy interprets the passage similarly.21 I will argue that, when we consider this passage in the context of Hume's overall argument in the section 'Of scepticism with regard to the senses', it does not support their interpretations. 15 In the part of the section where this passage occurs, Hume is considering three sources that might give us the ideas of continued and distinct existence: the senses, reason, and the imagination (T 1.4.2.2/188). He claims to eliminate the senses and reason (using, among others, the just-quoted argument about the senses), and concludes that these ideas derive from the imagination (T 1.4.2.3– 14/188–93). However, when Hume comes to explain how the imagination produces the idea of continued existence, he assigns an important role to the senses. In his view, the senses provide us with impressions that exhibit 'coherence and constancy', and our belief in continued existence 'depends on' these features of our impressions (T 1.4.2.20/195): if we did not receive impressions with these features, by way of our senses, then the imaginative mechanisms that produce the idea of continued existence, and enliven it into a belief, would not be triggered (T 1.4.2.20–43/195– 210). So, when Hume argues that our senses 'are incapable of giving rise to the notion of the continu'd existence of their objects', in the passage that Butler and Landy cite, he cannot consistently mean that our senses play no role in giving us this notion or idea. The strongest claim he can be making here is that the senses alone cannot give us this idea-in other words, that we cannot acquire the idea of continued existence just by copying it from an impression of sensation, as we might acquire an idea of a particular shade of red, or of a particular smell or taste.22 An idea can represent something as having a particular shade of red just in virtue of being copied from an impression of that shade.23 In contrast, Hume is arguing here, an idea cannot represent something as existing unperceived just in virtue of being copied from a sensory impression. This conclusion does not, by itself, commit Hume to NO IDEA. My opponents may be assuming that he would also accept this further claim: if an idea cannot have a certain representational property just in virtue of being copied from a sensory impression, then we do not have (at our 16 disposal) an idea with that representational property.24 Taken together with Hume's conclusion in the quoted passage, this further claim would commit him to NO IDEA. But Hume would not accept this further claim. 'Abstract' or 'general' ideas are a counterexample to it. These ideas allow us to represent things as belonging to general kinds: for example, to represent a particular creature as a man (T 1.1.7.2/17–18), or a particular shape as a triangle (T 1.1.7.8–9/21–22). But no idea can have this representational property just in virtue of being copied from a sensory impression. As we will see in more detail below (§4), abstract ideas owe their representational properties not just to the way in which they are copied from impressions, but to the way in which they are associated in the imagination with a 'general term' and a 'custom' of surveying other ideas (T 1.1.7.7–10/20– 22). So, the passage that Butler and Landy cite gives us no good reason to think that Hume means to argue for NO IDEA. His argument in this passage leaves it open that imaginative associations might allow an idea to represent something as existing unperceived, much as they allow an abstract idea to represent something as belonging to a general kind. (I will develop this suggestion in §5.) I conclude that my opponents' textual evidence is unconvincing: it does not show that Hume explicitly argues from the Copy Principle to NO IDEA. §4 IS HUME IMPLICITLY COMMITTED TO NO IDEA? My opponents might reply that, by accepting the Copy Principle, Hume at least implicitly commits himself to NO IDEA. Butler presents and endorses an argument that, if correct, would show this: Some commentators have argued that the fiction of continued existence is a violation of Hume's copy principle. Since we cannot observe something's being unobserved, the idea of 17 continued existence cannot be derived from experience (directly or by combining other ideas that are directly derived from experience). ... If 'continued existence' means 'existing unperceived' then it is true that we can have no idea of this because we can have no impression of anything existing unperceived from which the idea could be copied. ('Vulgar Fiction', 242– 43) Butler infers that, for Hume, 'continued existence' does not mean unperceived existence; hence, the Copy Principle allows for ideas that represent certain things as having continued existence ('Vulgar Fiction', 244–45). In effect, she acquits Hume of inconsistency by denying that he holds BELIEF (as discussed in §2). In contrast, I aim to show that Hume's acceptance of the Copy Principle does not commit him to NO IDEA. Butler's argument, and others like it, face a general obstacle. The Copy Principle concerns only simple ideas (T 1.1.1.7/4). So, the most one can hope to show using the Copy Principle, without invoking other general principles about mental representation, is that Hume is committed to: NO SIMPLE IDEA We do not have (at our disposal) a simple idea that represents anything as existing unperceived. My opponents must be thinking as follows. First, that Hume's acceptance of the Copy Principle commits him to NO SIMPLE IDEA. Second, that this commitment, together with constraints on the formation of complex ideas from simple ones, commits him to NO IDEA.25 It is not clear that my opponents could establish the second of these claims. In Hume's view, there are properties that only complex ideas can represent. For example, no simple idea can 18 represent spatial extension; only a complex idea, made up of simple ideas of visible or tangible points in a certain arrangement, can do so (T 1.2.3.12–14/38). For Hume, then, the fact that we do not have (at our disposal) a simple idea that represents anything as having a certain property does not, in general, imply that we do not have (at our disposal) an idea that represents anything as having that property. So, in order to show that NO SIMPLE IDEA commits Hume to NO IDEA, my opponents would need to show that there is something special about the property of existing unperceived, which prevents us from assembling simple ideas that do not represent this property into a complex one that does. However, I will argue that this issue is moot because my opponents' first claim, above, is false: it is not the case that Hume's acceptance of the Copy Principle commits him to NO SIMPLE IDEA. I will proceed by considering the three most plausible interpretations of the Copy Principle and arguing that none of them commits him to NO SIMPLE IDEA. First interpretation According to some scholars, the Copy Principle concerns only resemblance and causation, not representation. For example, according to Don Garrett and David Landy, the Copy Principle states merely that every simple idea exactly resembles (save for its degree of force and vivacity)26 and is caused by a previous simple impression.27 Garrett argues that being caused by and exactly resembling something is not sufficient for representing it.28 In his view, then, the Copy Principle does not imply that our simple ideas represent the impressions from which they are copied. Similarly, Landy claims that the Copy Principle, as he interprets it, is silent about what our simple ideas represent.29 (These scholars do not deny that Hume sees an important connection between 19 copying and representation, but they hold that his view about this connection is extraneous to the Copy Principle itself.)30 Hume's argument for the Copy Principle provides some support for this interpretation. He first argues that, for every simple idea, there is a simple impression that exactly resembles it, and vice versa (T 1.1.1.3–6/2–4). He then argues that the simple impressions cause the corresponding simple ideas, on the grounds that they precede and are necessary for those ideas (T 1.1.1.8–9/4– 5). These arguments about resemblance and causation exhaust his case for the Copy Principle, and he claims to have 'establish[ed]' this principle on their basis (T 1.1.1.7/4, 1.1.1.12/7). Garrett and Landy might cite this as evidence that the Copy Principle concerns only resemblance and causation, and is silent about representation. Otherwise, given Hume's goal of 'establishing' this principle (T 1.1.1.7/4), we would expect him to have asserted some link between representation and the claims for which he argues, or to have argued separately for a claim about what our simple ideas represent. Interpreted in this first way, the Copy Principle is silent about matters of representation. But NO SIMPLE IDEA concerns precisely such matters. So, interpreted in this first way, the Copy Principle does not commit Hume to NO SIMPLE IDEA. Second interpretation The Copy Principle can also reasonably be interpreted as stating that every simple idea exactly resembles, is caused by, and is a representation of a previous simple impression (let us call this impression the object of the idea). Hume's formulation of the Copy Principle provides some support for this interpretation because it seems to assert three relations: each simple idea i) is 'deriv'd from', ii) is 'correspondent to' and iii) 'exactly represents' a simple impression. Our first 20 interpretation of the Copy Principle accommodates relation (i), which is that of causation,31 and (ii), which is that of resemblance.32 But it seems to leave (iii) out of account. In contrast, our second interpretation accommodates (iii). Interpreted in this second way, the Copy Principle concerns what simple ideas represent. However, it still does not commit Hume to NO SIMPLE IDEA because it is silent about the properties or relations that our simple ideas represent their objects as having or as standing in. Compare: if we are told that every sentence in a certain book is a representation of Hume, this tells us nothing about what properties or relations those sentences represent him as having, or as standing in; for all we are told, the sentences in question might represent him as being wise, or as being foolish, or neither. Similarly, the principle that every simple idea is a representation of a simple impression tells us nothing about what properties or relations those simple ideas represent their correspondent simple impressions as having, or as standing in. For all that the principle tells us, the ideas in question might represent their correspondent impressions as being perceived, or as being unperceived, or neither.33 So, if our second interpretation of the Copy Principle is correct, Hume's acceptance of this principle does not commit him to NO SIMPLE IDEA. Third interpretation It may seem that our second interpretation still leaves something out of account. Hume says not just that every simple idea 'represents' its correspondent impression, but that it 'exactly represents' this impression (T 1.1.1.7/4, italics added). Here, it may be said, 'exactly' means accurately.34 Later in the Treatise, Hume claims that contradiction to 'truth and reason' consists in 'the disagreement of ideas, consider'd as copies, with those objects, which they represent' (T 2.3.3.5/415). This claim suggests that an idea copied from an object (or impression) predicates 21 something of it;35 and that, if the idea is copied exactly, then its object actually has, or actually stands in, the property or relation that the idea predicates of it-hence, that an exact copy is a truthful or accurate representation. As we have seen, Hume holds that every simple idea is caused by and exactly resembles-hence, is an exact copy of-a previous simple impression. It may be said that, taken together, these views recommend a third interpretation of the Copy Principle: every simple idea resembles, is caused by, and is an accurate representation of a previous simple impression.36 So interpreted, the Copy Principle may seem to commit Hume to NO SIMPLE IDEA. He argues that no impression exists unperceived or absent from the mind (T 1.4.2.45–46/210–11). So, if a simple idea represents an impression as existing unperceived, then it represents that impression falsely or inaccurately. But, by our third interpretation of the Copy Principle, every simple idea is an accurate representation of its correspondent impression. So, it may be claimed, Hume must accept that no simple idea represents its correspondent impression as existing unperceived. And so, he must accept NO SIMPLE IDEA. To answer this argument, I need to introduce a distinction between two species of representation: that which depends on associations between ideas and customs (hereafter, customdependent representation), and that which does not (custom-independent representation).37 Hume's theory of 'abstract' or 'general' ideas (T 1.1.7) provides an example of the former. Hume argues that an abstract idea is an 'image' of a particular object (T 1.1.7.6/20), e.g. a particular man (T 1.1.7.2/18) or a particular triangle (T 1.1.7.8/21). This 'image' comes to represent all members of a kind, e.g., all men or all triangles, by being associated with a word (a 'general term') that is, in turn, associated with many other ideas of particular members of that kind (T 1.1.7.7–10/20–22). For example, hearing the word "triangle"38 causes me to form an idea or 'image' of a particular 22 triangle-say, a particular red, equilateral one. It also disposes me to form other ideas of particular triangles that I associate with the word, but do not actually form on this occasion. As Hume puts it, hearing the word 'revive[s] a custom' of surveying ideas of other particular triangles (T 1.1.7.7/20). Because it is linked to this disposition or custom, via the word "triangle", my idea of a particular red, equilateral triangle represents all triangles. For brevity, let us call a custom that is associated with an idea, via linguistic item such as a general term, a linguistically mediated custom, and let us call the sort of representation distinctive of an abstract idea (that is, the representation of all members of a kind) abstract representation. In Hume's view, abstract representation could not occur without linguistically mediated customs, so it is an example of custom-dependent representation.39 Let us say that an abstract idea custom-dependently represents all members of a kind. Hume's theory of abstract representation appeals to associations among 'particular ideas' (T 1.1.4.7/13, 1.1.7.10/22), i.e. those that represent particular things, such as a particular man or triangle. A man is a substance; a triangle is a mode. Hume's account of how ideas represent particular substances and modes (T 1.1.6) provides further examples of custom-dependent representation. (Since it concerns ontological categories, let us call the sort of representation distinctive of ideas of substances and modes categorial representation.) Hume argues that an idea of a substance and an idea of a mode each represents a collection of 'particular qualities' (T 1.1.6.1–3/15–17). The representational difference between them-the fact that one represents a substance, the other a mode-is explained by their being associated with different linguistically mediated customs. For example, consider the particular sensible qualities of a beautiful statue: the particular shape, color, texture, degree of heat and cold, and so forth. According to Hume's theory, an idea of this collection of qualities represents the statue (a particular substance) if it is suitably 23 associated, via a name, with a custom of incorporating ideas of other qualities into the collection bearing that name, under certain circumstances (T 1.1.6.2/16). An idea of the same collection of qualities represents the beauty of the statue (a particular mode) if it is associated, via a name, with a different custom-a custom of disallowing certain changes to the collection of qualities bearing that name (T 1.1.6.3/17). An idea could not represent a substance or a mode, if not for its association with one of these linguistically mediated customs. So, like abstract representation, categorial representation is custom-dependent; when an idea represents a substance or mode, it does so custom-dependently. (§5, below, examines Hume's theory of categorial representation in more detail.) Much as Hume's theory of abstract representation appeals to associations involving particular ideas, his theory of categorial representation appeals to associations involving a species of particular ideas: those that represent 'particular qualities', such as colors, tastes, and smells (T 1.1.6.1–2/15–16). Hume does not posit any further customs, in order to explain how ideas manage to represent particular qualities. Instead, he seems to explain this kind of representation in terms of copying (T 1.1.6.1/15–16): an idea represents a particular quality in virtue of being copied from an impression of that quality. So, for Hume, the representation of particular qualities seems to be custom-independent; when an idea represents a particular quality, it does so custom-independently. Note that one and the same idea can represent both custom-independently and customdependently. For example, an idea of a substance custom-independently represents a collection of particular qualities; it custom-dependently represents the substance that has those qualities. In light of this distinction between two kinds of representation, I can now answer my opponents' argument that Hume must accept NO SIMPLE IDEA: the Copy Principle says that every simple idea 'exactly', i.e. accurately, represents its correspondent impression; but no impression 24 exists unperceived; so, no simple idea represents its correspondent impression as existing unperceived. My answer is that, when Hume says that every simple idea 'exactly represent[s]' its correspondent impression (T 1.1.1.7/4), he is best interpreted as speaking only of customindependent representation. To see this, consider again his argument for the Copy Principle. According to our third interpretation of this principle, it asserts three relations: every simple idea i) is caused by ('deriv'd from'), ii) resembles (is 'correspondent to'), and iii) accurately ('exactly') represents a previous simple impression. As we have seen, however, Hume's argument concerns only two of these relations: resemblance (T 1.1.1.3–6/2–4) and causation (T 1.1.1.8–9/4–5). He gives no further argument about representation. So, if our third interpretation of the Copy Principle is correct, he must be tacitly assuming that an idea's being copied from an impression (that is, being caused by and resembling it) suffices for its 'exactly represent[ing]' that impression, in his intended sense of "represent". However, being copied from an impression does not suffice for any sort of custom-dependent representation: an idea may be copied from an impression without being associated with any linguistically mediated customs, hence without custom-dependently representing anything. So, when Hume says that every simple idea 'exactly represent[s]' its correspondent impression, the intended sense of "represent" is presumably restricted to customindependent representation. (We should expect this restriction anyway because, at this stage in the Treatise, Hume has neither mentioned any linguistically mediated customs nor discussed the two main sorts of custom-dependent representation that he later examines, i.e. categorial and abstract representation.) Therefore, on the most plausible version of our third interpretation, the Copy Principle says: every simple idea is caused by and resembles a previous simple impression and customindependently represents this impression accurately. So interpreted, the Copy Principle does not 25 imply that every simple idea is an entirely accurate representation of its correspondent impression. An idea might custom-independently represent an impression accurately, but custom-dependently represent that impression inaccurately. For example, the idea might accurately represent the impression's intrinsic qualities, thanks to being accurately copied from it (custom-independent), but inaccurately represent the impression in some other respect, thanks to being associated with a linguistically mediated custom (custom-dependent). §5 will explain how such associations allow even simple ideas to custom-dependently represent their correspondent impressions as existing unperceived, which is to represent them inaccurately. And so, again, Hume's acceptance of the Copy Principle does not commit him to NO SIMPLE IDEA. Conclusion of §4 I conclude that my opponents fail to show that Hume's acceptance of the Copy Principle implicitly commits him to NO IDEA. To do so, they would first need to show that it commits him to NO SIMPLE IDEA. But I have argued that they fail to do so. None of the three most plausible interpretations of the Copy Principle commits Hume to NO SIMPLE IDEA. §5 THE COPY PRINCIPLE AND NEGATION A problem about negation My opponents might concede the points I have argued so far, but reply that Hume is committed to NO IDEA by the Copy Principle together with his view that all impressions are of positive qualities such as colors, sounds or tastes: I wou'd fain ask those philosophers, who found so much of their reasonings on the distinction 26 of substance and accident, and imagine we have clear ideas of each, whether the idea of substance be deriv'd from the impressions of sensation or of reflection? If it be convey'd to us by our senses, I ask, which of them; and after what manner? If it be perceiv'd by the eyes, it must be a colour; if by the ears, a sound; if by the palate, a taste; and so of the other senses. (T 1.1.6.1/15–16, second italics added) On this view, it is clear how an idea can represent its object as having one of these positive qualities-for example, as being colored, sonorous, or sweet-tasting. It will do so by being copied, or (in the case of a complex idea) by having a part that is copied, from an impression of this quality. But how can an idea represent its object as having a negative property, like that of being silent, insipid, or unperceived? My opponents may argue that no idea can do so, given that every idea is copied from, or wholly composed of ideas copied from, impressions of positive qualities (hereafter, positive impressions). If they are correct, this would be a further reason to think Hume is committed to NO IDEA. To see the problem for Hume here, consider the difference between i) thinking of the library where I am sitting and not thinking of it as being noisy, and ii) thinking of the library as not being noisy-as being quiet. In the first case, my thinking about the library is, as it were, neutral with respect to whether the library is noisy; let us call this kind of thinking noise-neutral. In the second case, my thinking about the library is not neutral in this way, but negates the presence of noise; let us call this kind of thinking noise-negating. (The intended contrast here is between two thinkings or entertainings of thoughts about the library, not between two beliefs.) For Hume, these two kinds of thought must involve ideas that differ representationally. Noiseneutral thought calls for an idea of the library that does not represent it as noisy. Noise-negating 27 thought calls for an idea of the library that does represent it as not noisy. But how can this difference be captured by ideas whose only parts are copied from positive impressions-for example, impressions of the library's colors, textures and smells? When combining ideas of the library's positive qualities into a complex idea of the library, I seem to have only two options: I can include ideas of noises in this complex idea, or I can refrain from including them. If I take the first option, then my idea represents the library as noisy, and will not serve for either noise-neutral or noise-negating thought. If I take the second option, then my idea will serve equally well for either kind of thought; hence, my thought will be indeterminate between being noise-neutral and being noise-negating. There does not seem to be any idea of a positive quality that I can add to or subtract from my idea of the library that would make my thought determinately noise-neutral rather than noise-negating, or vice versa. But if, in general, it cannot be determinately true that an idea represents something as not existing, not having a certain property, or not standing in a certain relation, then-in particular-it cannot be determinately true that an idea represents something as existing unperceived (that is, as existing and not being perceived). If Hume is committed to accepting this, then he is committed to NO IDEA. This argument raises a general problem for Hume's theory of mental representation: how can ideas represent negation?40 Our problem about unperceived existence is a special case of this more general problem. The view that Hume cannot account satisfactorily for negation is almost as old as the Treatise itself. In Hume's own lifetime, Thomas Reid objected that Hume cannot account for the difference between the affirmer, who believes firmly that there is an afterlife; the agnostic, who neither believes nor disbelieves that there is an afterlife; and the denier, who believes firmly that there is no afterlife41 (the names for Reid's characters are mine). According to Reid, the problem derives from Hume's view that a belief is a 'lively idea', i.e. one with a relatively high 28 degree of force and vivacity (T 1.3.7.5/96). Reid infers that the affirmer must have a 'strong and lively' idea of an afterlife, the agnostic a 'weak and faint' idea.42 But what of the denier? If Hume says that the denier has a lively idea of an afterlife, then he erroneously equates the denier's mental state with the affirmer's. If he says that the denier has a faint idea of an afterlife, then he erroneously equates the denier's mental state with the agnostic's.43 Reid claims that Hume has no further options, hence cannot account satisfactorily for denial. If Hume could explain how an idea represents there not being an afterlife, he could easily answer Reid's argument. He could say that the affirmer and the denier both have 'strong and lively' ideas, but that these ideas differ representationally: the affirmer's lively idea represents there being an afterlife; the denier's represents there not being an afterlife.44 (Meanwhile, the agnostic may have both ideas, but neither will be lively.) But the argument I have offered my opponents, based on the Copy Principle and Hume's view that all impressions are positive, seems to block this line of reply: if correct, this argument shows that Hume cannot explain how an idea represents there not being an afterlife.45 In the rest of this section, I aim to show that Hume can satisfactorily account for negation, using only resources that he allows himself in other contexts. If successful, this provides an answer to Reid's objection. I then try to explain how, in particular, an idea can represent its object as existing unperceived. If successful, this shows that Hume is not committed to NO IDEA, and thereby acquits him of the inconsistency presented in §1. Solution to the general problem: negation Hume does not raise or address the general problem about negation. But this problem has the same structure as two others that he does address, when discussing categorial and abstract representation 29 (T 1.1.6, 1.1.7). In all three cases, the problem is to explain how two or more ideas that are copied from the same impression(s) can differ in what they represent. With respect to negation, the problem is to explain, for example, how two ideas each copied from impressions of a library's positive qualities can differ as follows: one idea does not represent the library as noisy (noiseneutral), while the other does represent the library as not noisy (noise-negating). Hume's theories of categorial and abstract representation aim to solve problems of just this sort. Hume's theory of abstract representation aims to explain how two ideas copied from the same impression can represent different kinds: say, all (and only) triangles in one case, all shapes in the other. His explanation appeals to linguistically mediated customs (see §4). Two ideas copied from the same impression represent different kinds if they are associated, via general terms, with different customs: for example, if one idea is associated, via the word "triangle", with a custom of surveying all and only one's ideas of other particular triangles, and the other is associated, via the word "shape", with a custom of surveying all and only one's ideas of other particular shapes. Similarly, Hume's theory of categorial representation aims to explain how two complex ideas copied from the same collection of impressions can represent things of different ontological categories-for example, a statue (a particular substance) in one case, the beauty of that statue (a mode) in the other-and does so by appealing to linguistically mediated customs. We have already seen a sketch of this theory (§4); let us now examine it in more detail. Consider a particular beautiful statue-say, Michelangelo's David. Each of our impressions, when perceiving the David, is of a particular sensible quality: a color, a texture, a degree of heat and cold, and so forth (T 1.1.6.1/15–16). A complex idea copied from such impressions will serve equally well for thinking about the David (a substance) and for thinking about the David's beauty (a mode). So, merely forming such an idea leaves it indeterminate whether I am thinking about the 30 David or its beauty. There does not seem to be any sensible quality that I can add to or subtract from the collection of qualities represented by this idea, so as to make my thinking determinately about the David rather than its beauty, or vice versa. How, then, can Hume account for thinking that is determinately about one, rather than the other, of these things? Hume's answer appeals to linguistically mediated customs. The idea of a substance and that of a mode each 'have a particular name assign'd them' (T 1.1.6.2/16). And they are associated, via their assigned names, with different customs. When an idea represents a mode, it is associated with a custom of disallowing certain changes to the collection of qualities that it represents: The simple ideas of which modes are form'd, either represent qualities, which are not united by contiguity and causation, but are dispers'd in different subjects; or if they be all united together, the uniting principle is not regarded as the foundation of the complex idea. The idea of a dance is an instance of the first kind of mode; that of beauty of the second. The reason is obvious, why such complex ideas cannot receive any new idea, without changing the name, which distinguishes the mode. (T 1.1.6.3/17, italics added) Suppose I entertain an idea of the David's sensible qualities in association with the name "beauty". And suppose that this name revives a custom of disallowing certain changes to the collection of qualities represented by my idea: for example, of disallowing me from imagining the David's being defaced, leaving it no longer beautiful. Insofar as my idea is associated with a custom of disallowing just this kind of change, it represents the beauty of Michelangelo's David-a mode- rather than the substance that has this mode. (Hume indicates that, if I were to change my idea in one of the disallowed ways, this would 'chang[e] the name, which distinguishes the mode': that 31 is, the association between the idea and the name "beauty" would be broken, and so the idea would no longer be associated with the linguistically mediated custom that "beauty" revives.) In contrast, when an idea represents a substance, it is associated with a different custom whereby changes to the collection of qualities that it represents are allowed: Thus our idea of gold may at first be a yellow colour, weight, malleableness, fusibility; but upon the discovery of its dissolubility in aqua regia, we join that to the other qualities, and suppose it to belong to the substance as much as if its idea had from the beginning made a part of the compound one. (T 1.1.6.2/16) Returning to our example, suppose I entertain an idea of the David's sensible qualities in association with the name "David", rather than "beauty". And suppose that this name revives a custom whereby changes to the collection of qualities represented by this idea are allowed: for example, a custom whereby I am allowed to change this collection, so as to imagine the David's being defaced. (Here, making this change would not break the association between my idea and the name "David".) Insofar as it is associated with a custom of allowing such changes, my idea represents the David itself-a substance-rather than a mode, such as its beauty. I propose that Hume can account in the same way for the representational difference between the ideas used for noise-neutral and noise-negating thought about the library, as follows. Like our ideas of Michelangelo's David and of the David's beauty, these ideas are copied from the same collection of impressions-in this case, impressions of the library's positive qualities. (Since these qualities do not include any noises, neither idea represents a noise.) But the two ideas are associated with different linguistically mediated customs. In noise-negating thought, where we do represent 32 the library as not being noisy, our idea is associated with a custom of disallowing the introduction of noises into that idea. This association may be mediated by a word or phrase like "quiet" or "no noise here". Thanks to its association with this custom, our idea represents the library as not being noisy, much as an idea copied from impressions of the David's sensible qualities represents the David's beauty, rather than the David itself, when it is associated with a similar custom of disallowing certain changes. In contrast, the idea that we use for noise-neutral thought has no such custom associated with it. As a result, this idea merely does not represent the library as being noisy. On this account, the representation of negation-like categorial and abstract representation-is custom-dependent. It is worth emphasizing that, on this account, an idea need not be complex in order to represent an instance of negation. Hume notes that a simple idea can be associated with the kind of linguistically mediated custom that allows it to serve as an abstract idea-for example, as an idea that represents all simple ideas (T 1.1.7.7n/637). Analogously, on the account of negation I am offering him, a simple idea can be associated with the kind of linguistically mediated custom that allows it to represent an instance of negation. For example, a simple auditory idea of a particular musical note will represent this note as unaccompanied (that is, as not being accompanied) if the idea is associated with a linguistically mediated custom whereby we are disallowed from adding ideas of other musical notes to it.46 I do not claim that Hume himself formulated the account of negation I have offered him. But it would be disappointing if the account were not, at least, consistent with what he does say on the matter. So, let us consider this. The Treatise says frustratingly little to explain how ideas represent negation, giving only this hint, while discussing contrariety: 33 [N]o two ideas are themselves contrary, except those of existence and non-existence, as implying both of them an idea of the object; tho' the latter excludes the object from all times and places, in which it is suppos'd not to exist. (T 1.1.5.8/15) This passage makes two pertinent claims. First, that an idea of a certain object's nonexistence in a certain place, at a certain time, 'excludes' that object from that place at that time. The account I have offered Hume could reasonably be expressed in this way. On this account, an idea would represent an object's nonexistence in a certain place, at a certain time, by i) representing that place at that time, ii) not representing the object in that place at that time, and iii) being associated with a linguistically mediated custom of disallowing the introduction of that object into our idea.47 Insofar as an idea meets these conditions, it can be said to 'exclude' the object in question from the place and time that it represents. Second, Hume claims that the idea of an object's nonexistence resembles that of the object's existence, 'as implying both of them an idea of the object.' I take him to mean that, in order to have an idea of a certain object's nonexistence, one must have (at one's disposal) an idea of that object.48 The account I have offered respects this claim. On this account, an idea represents an object's nonexistence by being associated with a custom of disallowing the introduction of that object into that idea. It seems plausible that one cannot have any customs, with respect to a certain object, unless one can think of that object; and, given Hume's theory of thought, one cannot think of that object unless one has (at one's disposal) an idea of it. So, on the account I have offered, one's idea can represent the nonexistence of a certain object only if one also has (at one's disposal) an idea of that object. And so, this account is consistent with Hume's own brief remarks about contrariety in the Treatise.49 34 I have argued that, by using the resources he allows himself when explaining categorial and abstract representation-in particular, his account of linguistically mediated customs-Hume can solve the general problem, raised by Reid, Stroud and others, about how ideas represent negation. Let us now apply this account to the particular case of unperceived existence. Solution to the particular problem: unperceived existence Before addressing how ideas represent their objects as existing unperceived, we must first consider how an idea represents its object as perceived. In connection with our 'vulgar' belief, Hume uses the term "perceived" interchangeably with the phrases "present to the senses" and "present to the mind" (T 1.4.2.2/188, 1.4.2.37/206). He explains what it is for something to be perceived, or present to the mind or senses, as follows: External objects are seen, and felt, and become present to the mind; that is, they acquire such a relation to a connected heap of perceptions, as to influence them very considerably in augmenting their number by present reflections and passions, and in storing the memory with ideas. (T 1.4.2.40/207) (Hume is using the terms "object" and "perception" interchangeably here, because he is characterizing the 'vulgar' belief that fails to distinguish objects from perceptions; see T 1.4.2.31/202. Hence, later in the same paragraph, he writes of '[t]he supposition of the continu'd existence of sensible objects or perceptions', T 1.4.2.40/208.) In Hume's view, then, being perceived is a causal relation between a thing (in fact, an impression) and a mind: it is being related to a mind so as to cause certain kinds of reflections, 35 passions and memory-ideas in it. Taken together with his discussion of the perceptions involved in our cognition of causality (T 1.3.2.5–11/75–77, 1.3.14.1/155, 1.3.14.14–31/162–70), this suggests that an idea will represent an impression as being perceived in the following way. First, it must represent that impression as being contiguous to a mind (in time, and perhaps also in space, insofar as the mind's perceptions are spatially located);50 second, it must represent that mind as acquiring new perceptions-reflections, passions, and memory-ideas-after becoming contiguous to that impression; and third, it must represent a necessary connection between that impression's becoming contiguous to that mind, and that mind's acquiring those new perceptions. Hume suggests that there are two ways for it to meet this third condition, corresponding to his two definitions of a cause (T 2.3.2.4/409; for the two definitions, see T 1.3.14.31/169–70): the person who forms the idea must represent all similar configurations of impressions and minds as being followed by similar acquisitions of perceptions by those minds (T 1.3.6.3/87, 1.3.14.1/155); or, when considering any such configuration of an impression and a mind, he or she must feel determined to expect that mind to acquire such new perceptions (T 1.3.14.20/164–65).51 We now need to explain, on Hume's behalf, how an idea can represent an object as existing and not being perceived-that is, not bearing this distinctive causal relation to any mind. Suppose we form an idea of the object in question: say, as in Hume's example, a piece of furniture or, more properly speaking-since the 'vulgar' belief is our concern here-a furniture-impression (T 1.4.2.35/204). In Hume's view, every idea automatically represents its object as existing, simply in virtue of representing it: 'Whatever we conceive, we conceive to be existent. Any idea we please to form is the idea of a being; and the idea of a being is any idea we please to form' (T 1.2.6.4/67). So, like all Humean ideas, our idea of the furniture-impression will represent the impression as existing. Now, suppose that this idea is associated with a linguistically mediated custom, whereby 36 we are disallowed from introducing, into the idea, a perceiver of the furniture-impression: that is, we are disallowed from changing the idea so that it represents the furniture-impression as perceived, in the way described above. The association between the idea and this custom may be mediated by the word "unperceived" or (more likely, in the case of the 'vulgar') the phrases "not felt", "not seen", and so forth.52 Given the general account of negation that I have offered Hume, this idea will then represent the furniture impression as existing and as not being perceived.53 This account is consistent with Hume's other commitments. He is committed to holding that our idea of the furniture-impression is wholly composed of simple ideas that are copied from positive impressions. If our second interpretation of the Copy Principle is correct, then each of these simple ideas must represent a positive impression. If our third interpretation of the Copy Principle is correct, then each of these simple ideas must custom-independently represent a positive impression accurately. This is all consistent with Hume's saying that, in this case, our idea of the furniture-impression is associated with a linguistically mediated custom enabling it to represent the furniture-impression as existing unperceived-hence, that our idea customdependently represents the impression inaccurately. So, Hume is not committed to NO IDEA, despite accepting the Copy Principle and the view that all impressions are positive. A challenge to this account Hume's account of the ideas of substances and modes, and the parallel account of negation that I have offered him, invite the following challenge: how are the relevant linguistically mediated customs established?54 For example, how do we come to associate an idea of the David's sensible qualities with the kind of custom that makes for a representation of the David's beauty, rather than of the David itself, or of some other of its modes? Similarly, how do we come to associate an idea 37 of a furniture-impression with the kind of custom that makes for a representation of this impression as being unperceived? Hume does not acknowledge or address this challenge (T 1.1.6). This is a shortcoming of his account of categorial representation, and of the account of negation I have modeled on it. But we can guess at how he might answer it. For example, he might conjecture that we are taught, as children, to apply the word "beauty" where certain sensible qualities are present and to withhold it otherwise, by means of reward and punishment, or praise and correction. Due to this linguistic training, insofar as an idea is associated with the word "beauty", we would customarily disallow certain changes to it-specifically, we would disallow changing this idea, so that it depicted features from which we have been taught to withhold the word "beauty". Similarly, we may be taught to apply the phrases "not felt", "not seen", and so forth to objects that are absent from us (for example, to apply them to the furniture in our home, when we are elsewhere) and to withhold them otherwise (for example, to withhold them from the furniture in our home, when we are there and perceive it). In order to receive this training, we would need to be able to think about these objects when they are absent from us; but we would not, prior to the training, need to be able to think of them as absent from us.55 Conclusion of §5 I have argued that Hume can consistently explain how an idea represents an instance of negation and, more specifically, how an idea represents its object as existing unperceived, using only resources that his theory of ideas allows him and that he himself uses when facing similar challenges (those concerning categorial and abstract representation). So, he can consistently reject NO IDEA. This paper's main argument is now complete. We saw that Hume seems committed to the 38 inconsistent triad of BELIEF, BELIEF®IDEA, and NO IDEA (§1). I have argued that he is committed to BELIEF and, since he also holds BELIEF®IDEA, cannot consistently accept NO IDEA (§2). But this is unproblematic because, contrary to what some scholars claim, Hume does not explicitly argue for NO IDEA (§3) and is not implicitly committed to it (§§4–5). So, he is not committed to the inconsistent triad. §6 POWELL AND GARRETT ON NEGATION In recent publications, Lewis Powell and Don Garrett have also offered Hume solutions to the general problem of how ideas represent negation.56 Before concluding, let us compare these with my preferred solution. Powell offers two solutions, without choosing between them ('Denial', 14–16). First, he suggests that Hume might posit simple ideas that have 'intrinsically negative contents' or that are 'negative in a fundamental sense' ('Denial', 14–15)-in other words, that do not represent any positive entities, but merely represent absences of things. As Powell candidly admits, this solution conflicts with Hume's stated views ('Denial', 20). Per the Copy Principle, simple ideas with 'intrinsically negative contents' must be copied from corresponding negative impressions, i.e. impressions of mere absences. But Hume explicitly rules this out: as we have seen, he holds that all impressions are of positive qualities, not mere absences (T 1.1.6.1/15–16). Second, Powell suggests that Hume might 'assign a sort of dual role to certain contents', and say-for example-that '[s]ome idea is an idea of something positive in its own right, as well as being the idea of the nonexistence of the sun' ('Denial', 14).57 When Powell's second proposal is described at this level of generality, my account is a version of it. On my account, every idea is copied from a positive impression (or impressions), hence is 'of' (custom-independently 39 represents) 'something positive in its own right'-a positive quality (or qualities)-but some ideas also custom-dependently represent things as not existing, as not having certain properties, or as not standing in certain relations. However, Powell develops his second proposal differently. Instead of appealing to linguistically mediated customs, he appeals to a spatial relation whereby an idea 'crowds out' certain objects, and thereby represents their nonexistence ('Denial', 16). In his whimsical example, an idea might represent Dumbo the elephant's nonexistence by representing the world as full of chocolate pudding, leaving no room for Dumbo ('Denial', 16).58 However, this appeal to 'crowding out' cannot be applied to all the representations of negation that Hume would wish to explain. For example, he would presumably wish to explain how an idea can represent a certain apple as not being sweet. But he holds that various kinds of qualities, including tastes, can neither have nor be conceived to have spatial locations (T 1.4.5.9–14/235–9). So, he cannot consistently say that an idea represents an apple as not being sweet by representing the apple as spatially filled with sourness or any other taste that would 'crowd out' sweetness.59 My account avoids this problem. It says that if an idea of a certain apple is associated with a linguistically mediated custom whereby we are disallowed from incorporating an idea of sweetness into it, then this idea represents the apple as not being sweet. There is no need for the idea to depict any further quality that would 'crowd' sweetness 'out' of the apple. The differences between Powell's solutions and mine may derive partly from our different choice of starting points. Powell focuses on negative existential ideas: that is, ideas of the 'absences' of nonexistent things such as Dumbo. In contrast, my main goal has been to explain negative predicative ideas: that is, ideas that represent things as not having certain properties or not standing in certain relations, like that of being perceived. Powell may hope to explain negative predicative ideas in terms of negative existential ones: for example, to explain how an idea can 40 represent a certain apple as not being sweet (a negative predicative representation) in terms of its representing the absence or nonexistence of sweetness in that apple (a negative existential representation). In contrast, I take Hume's discussion of contrariety to suggest that negative existential ideas are to be explained in terms of negative predicative ones: an idea represents an object's nonexistence by excluding it from all times and places (T 1.1.5.8/15)-in other words, by predicating not containing this object of all times and places. My account of negation has more in common with Garrett's proposal than with either of Powell's proposals. For Garrett, a mind may represent the nonexistence of a particular object, quality or event at a particular place and time by i) representing the place at that time, ii) not representing the object, quality or event in it, and iii) 'being mentally resistant to including a representation of the object, quality or event in it' (Hume, 76).60 It may be objected that Garrett's talk of 'mental resistance' is out of place here. We are trying to explain, on Hume's behalf, how we can entertain the thought that an object does not exist, lacks a certain property, or does not stand in a certain relation. Someone who entertains the thought that the library is not noisy need not be 'mentally resistant' to including ideas of noises in her idea of the library, in any ordinary sense of "resistant". For example, suppose someone is wondering whether or not the library is noisy, and in doing so entertains both the thought that it is noisy and the thought that it is not. This person may vacillate without difficulty-without encountering any 'resistance', in an ordinary sense-between ideas of the library that do not include noises and ideas of the library that do. Garrett's talk of 'resistance' seems more appropriate to someone who (does not merely entertain the thought, but) believes that the library is not noisy.61 In the Treatise, Hume notes that we have difficulty imagining things that are contrary to what we believe. For example, when we see someone cast a die, we 'cannot without violence regard [the die] as suspended in the 41 air' (T 1.3.11.11/128). But this is because the 'constant conjunction', in our past experience, between a die's being cast and its falling 'has produc'd such a habit in the mind, that it always conjoins them in its thought, and infers'-that is, forms a belief or lively idea that represents- 'the existence of the one from that of its usual attendant' (T 1.3.11.11/128). But Hume does not suggest that we have difficulty conceiving things contrary to what we (do not believe, but) merely entertain in thought. Instead, in contexts that do not concern belief, he emphasizes that the imagination is free to separate and unite different ideas at pleasure (see, especially, T 1.1.3.4/10, 1.1.4.1/10–11, and Abs 35/661–62). Garrett would likely reply that he is using the term "resistance" in a technical sense. He notes that mental resistance can take different forms. For example, if one forms an idea that represents a certain place as full, leaving no room for a certain object-as in Powell's account of 'crowding out'-one is thereby 'resistant', in the relevant sense, to including a representation of that object in one's idea of that place (Hume, 76). Garrett argues that, since non-spatial qualities like tastes cannot be 'crowded out' in this way, there must be other forms of mental resistance (Hume, 76). He therefore posits 'a more general mode of resistance', which would 'consist in a tendency not to include' a representation of the relevant object in one's idea of the relevant place (Hume, 76). As it stands, this reply is underdeveloped. Garrett needs to explain what it is to have a 'tendency not to include' a representation of a certain object, quality or event in one's idea of a certain place. When I think of London, I do not tend to include any representations of sloths in my idea of it. This does not imply that, when I think of London, I mentally represent it as not containing sloths, or, in Garrett's terms, that I represent the nonexistence of sloths in it. (I have often thought of London, but I have never before considered whether it contains any sloths. So, I have mentally represented it neither as containing sloths nor as not containing them.) Garrett therefore needs to 42 explain what more is involved in having a tendency not to include a representation of a certain object in one's idea of a certain place, beyond merely lacking a tendency to include a representation of that object in that idea. Broadly speaking, Garrett has two options here. First, he might explain a 'tendency not to include [a representation]' in terms of linguistically mediated customs. For example, he might say: having a tendency not to include a representation of sloths in one's idea of London is to associate the latter idea with a linguistically mediated custom-mediated, perhaps, by the term "slothfree"-whereby one is disallowed from introducing a representation of a sloth into it. Of course, this involves accepting the core of my account of negation. Second, Garrett could appeal to something other than such customs: for example, he could say that a 'tendency not to include [a representation]' involves a distinctive, unpleasant feeling upon trying to include this representation, or that it involves a distinctive unwillingness to do so. The first option has at least two advantages. It appeals only to explanatory resources that Hume himself explicitly uses in other contexts, when facing parallel problems (T 1.1.6 and 1.1.7): the distinction between custom-independent and custom-dependent representation; and the appeal to linguistically mediated customs in order to explain how two ideas that are copied from impressions of the same qualities (hence, that custom-independently represent the same qualities) can differ in what they custom-dependently represent. In contrast, Garrett's second option involves introducing new resources, beyond those that Hume uses in these other contexts. Also, the first option helps Garrett steer clear of the objection we considered above: that 'mental resistance' characterizes the mind of someone with a belief, not someone who merely entertains a thought. Hume appeals to linguistically mediated customs to explain the representational properties of the ideas that we use when entertaining thoughts of substances and modes (T 1.1.6) and thoughts of kinds (T 1.1.7). In 43 his view, such customs are not peculiar to the mind of someone with a belief about, or lively idea of, these things. In contrast, it is not clear how Garrett could spell out his second option without falling prey to the objection. For example, if he characterizes the 'tendency not to include [a representation]' in terms of a feeling of resistance, it could fairly be objected that such feelings (if they exist at all) are peculiar to the mind of someone with a belief. When one is merely wondering whether or not the library is noisy, one need not feel any resistance to including representations of noises in one's idea of the library. It seems, then, that the most promising way to develop Garrett's account of negation is in the direction of the one I have offered Hume, with its appeal to linguistically mediated customs. §7 ANIMAL BELIEF IN BODY62 I conclude by addressing an objection. Some scholars say that Hume regards non-human animals (hereafter, animals) as sharing our belief in body.63 This claim seems to conflict with my interpretation. I have argued that, for human beings, believing in body involves believing certain things to exist unperceived (§2). If animals share this belief, then they must have (at their disposal) ideas that represent certain things as existing unperceived. On the account I have proposed (§5), having such ideas constitutively involves having linguistically mediated customs. But it seems that animals cannot have such customs, for they lack language.64 So, it seems, if Hume holds that animals share our belief in body, then he cannot consistently accept my proposed account of how ideas manage to represent things as existing unperceived. However, it is not clear that Hume regards animals as sharing our belief in body.65 Butler gives the following evidence that he does: in the Treatise, he claims that 'we must take for granted in all our reasonings' that 'there be body' (T 1.4.2.1/187) and that 'beasts are endow'd with thought and 44 reason as well as men' (T 1.3.16.1/176). Butler infers that, for Hume, beasts also take for granted- hence, believe-that there are bodies or things with continued and distinct existence ('Vulgar Fiction', 237). But this argument is unpersuasive. Hume's claim that we must take the existence of bodies for granted 'in all our reasonings' is likely hyperbole: it is implausible that we must do so in our arithmetic or geometric reasonings, for example. He need only claim that we must take the existence of body for granted in any piece of reasoning that could establish the existence of body: this suffices for his desired conclusion that we cannot establish the existence of body by any (non-question-begging) piece of reasoning. But this weaker claim, taken together with his view that animals reason, does not imply that animals share our belief in body. Section XII of the first Enquiry may also be cited as evidence that Hume regards animals as sharing our belief in body. Here, he claims that 'without any reasoning, or even before the use of reason, we always suppose an external universe, which depends not on our perception, but would exist, though we and every sensible creature were absent or annihilated' (E 12.7/151). He immediately adds: 'Even the animal creation are governed by a like opinion, and preserve this belief of external objects, in all their thoughts, designs, and actions' (E 12.7/151). My opponents may infer that, in his view, animals share our belief in things with distinct existence. If this inference is correct, then my interpretation is in trouble: distinct existence involves the capacity to exist unperceived; plausibly, a creature can mentally represent something as having this capacity only if that creature can mentally represent that thing as existing unperceived; and, if my proposed account is correct, then non-linguistic animals cannot do the latter. However, it is not clear that my opponents' inference is correct. In the Treatise, Hume distinguishes two components of distinct existence: (i) 'external position', i.e. location outside the mind; and (ii) 'independence of ... existence and operation' (T 1.4.2.2/188). In the Enquiry, he 45 continues to hold that our belief in body represents things as having both components of distinct existence: 'This very table, which we see white, and which we feel hard, is believed to exist, independent of our perception, and to be something external to our mind, which perceives it' (E 12.8/151–52). But when he characterizes animals' belief in body, he does not explicitly say that it represents things as having both components of distinct existence. He says only that it represents things as external: 'Even the animal creation are governed by a like opinion, and preserve this belief of external objects, in all their thoughts, designs, and actions' (E 12.7/151, italics added). It is therefore 'like' our belief in body ('a like opinion'), because our belief also represents things as external. But Hume can accept that animals' belief in body is 'like' ours in this respect, without committing himself to the view that animals believe in things with continued or independent existence. Only the latter view would conflict with my proposed account of how ideas manage to represent things as existing unperceived. My opponents might reply that, when Hume says that animals 'preserve this belief of external objects' (E 12.7/151), the demonstrative phrase "this belief" refers to the belief he has attributed to human beings in the previous sentence, hence to a belief in independent things. But this reply is not clearly correct. The referent of "this belief" could equally be the 'like opinion' that Hume has attributed to animals earlier in the sentence where the demonstrative phrase appears. And, as we have seen, the text allows that this 'like opinion' may be a belief in external things only, not a belief in independent things. Therefore, the objection from animal belief fails. We have found clear textual evidence that Hume regards animals as sharing our belief in external things, but no clear evidence that he regards them as sharing our belief in continued and independent things. In this paper, I have focused on explaining how ideas manage to represent things as existing unperceived. The account that I have 46 offered Hume is silent about how ideas manage to represent things as external. So, this account is compatible with his view that non-linguistic animals believe in external things. However, I can offer my opponents the following concession. My account allows that, when certain things are unperceived, animals believe those things to exist. We can regard this as a cognitively undemanding form of belief in continued existence. As we saw in §2, some scholars think that Hume attributes only this undemanding form of belief to 'vulgar' humans. I have argued that these scholars are mistaken: in order to make consistent sense of the Treatise, we must interpret Hume as attributing a more demanding form of belief to 'vulgar' humans-in his view, 'vulgar' humans believe certain things to exist unperceived (§2). This does not, of course, prevent him from also attributing the undemanding form to humans and regarding animals as sharing it.66 1 References to 'T' are to David Fate Norton and Mary J. Norton (eds.), A Treatise of Human Nature, two volumes (Oxford: Clarendon Press, 2007), with book, part, section and, where appropriate, paragraph numbers (references to paragraphs of the 'Abstract' are preceded by 'Abs'). References to 'E' are to Tom L. Beauchamp (ed.), An Enquiry concerning Human Understanding (Oxford: Clarendon Press, 2000), with section and paragraph numbers. These are followed, respectively, by the corresponding page numbers in L. A. Selby-Bigge and P. H. Nidditch (eds.), A Treatise of Human Nature, rev. edn. (Oxford: Clarendon Press, 1978), and L. A. Selby-Bigge and P. H. Nidditch (eds.), Enquiries concerning Human Understanding and concerning the Principles of Morals, 3rd edn. (Oxford: Clarendon Press, 1975). 2 I say only 'seems to argue' because I wish to be ecumenical about whether Humean beliefs are best understood as lively ideas or dispositions; for discussion, see below. 3 Louis E. Loeb, Stability and Justification in Hume's Treatise [Stability and Justification] (New 47 York: Oxford University Press, 2002), 65–74. Several others claim to find dispositional elements in Hume's account of belief, e.g. Stephen Everson, 'The Difference between Feeling and Thinking', Mind, 97 (1988), 401–13, at 408–10; Kaveh Kamooneh, 'Hume's Beliefs', British Journal for the History of Philosophy, 11 (2003), 41–56; and Barry Stroud, Hume (New York: Routledge and Kegan Paul, 1977), 74. For arguments against these interpretations and Loeb's, see Jennifer Smalligan Marušić, 'Does Hume Hold a Dispositional Account of Belief?', Canadian Journal of Philosophy, 40 (2010), 155–84. 4 Loeb, Stability and Justification, 75, 162–64, 170–71, 191n20. This view applies to what Loeb calls 'genuine' or 'strictly meaningful' beliefs (Stability and Justification, 170–71). He argues that, for Hume, when we lack a suitable idea for a genuine belief, we may have a 'quasi belief' that has 'quasi content' despite being 'strictly meaningless' (Stability and Justification, 166–72). But he also claims that, for Hume, our 'vulgar' belief in things with 'a continued existence when not present to the senses' is a genuine belief (Stability and Justification, 164, 172–73). So, Loeb would agree that Hume's view implies that we have (at our disposal) an idea that represents the content of this 'vulgar' belief (Stability and Justification, 191n20). 5 For variations on this argument, see Annemarie Butler, 'Hume on Believing the Vulgar Fiction of Continued Existence' ['Vulgar Fiction'], History of Philosophy Quarterly, 27 (2010), 237–54, at 242–43; David Landy, Kant's Inferentialism: The Case Against Hume [Kant's Inferentialism] (New York: Routledge, 2015), 34–35; Oliver A. Johnson, The Mind of David Hume (Urbana and Chicago: University of Illinois Press, 1995), 261; H. H. Price, Hume's Theory of the External World [External World] (Oxford: Clarendon Press, 1940), 134–35; Jan Wilbanks, Hume's Theory of Imagination [Imagination] (The Hague: Martinus Nijhoff, 1968), 154; and John P. Wright, Hume's A Treatise of Human Nature: An Introduction [Introduction] (New York: Cambridge 48 University Press, 2009), 140–41, 151. Landy's argument appeals not to the Copy Principle but to what he calls the Representational Copy Principle (RCP): that every simple idea [only] represents that of which it is a copy, and every complex idea [only] represents the referents of its constituent simple ideas as being arranged in the way those simple ideas are themselves arranged in the complex (Kant's Inferentialism, 29, 46–47; I have interpolated the two occurrences of 'only', without which the arguments that Landy attributes to Hume would be invalid). I do not think Hume accepts RCP; some reasons why will emerge in §§4 and 5. Wright's argument has a weaker conclusion: that we have 'no legitimate idea' of 'continued unperceived existence' (Introduction, 141); by 'legitimate', Wright seems to mean 'fully coherent' (Introduction, 140). Others who think Hume committed to NO IDEA include Timothy Costelloe, 'Hume's Phenomenology of the Imagination', Journal of Scottish Philosophy, 5 (2007), 31–45, at 37; and Robert Sokolowski, 'Fiction and Illusion in David Hume's Philosophy', The Modern Schoolman, 45 (1968), 189–225, at 201. Sokolowski suggests a different argument for this interpretation. He claims that, for Hume, it is a contradiction that a perception should exist unperceived, or absent from the mind. Taken together with Hume's views that we cannot conceive anything contradictory (T 1.1.7.6/19–20, 1.2.2.8/32, 1.2.4.11/43, 1.3.3.3/79–80, T Abs 11/650) and that conceiving something is forming an idea that represents it (T 1.2.6.8/67), this implies NO IDEA. But Sokolowski is mistaken: Hume does not think that a perception's unperceived existence is contradictory ('The supposition of the continu'd existence of sensible objects or perceptions involves no contradiction', T 1.4.2.40/208). Sokolowski misreads a passage that raises an objection (T 1.4.2.37/206) and takes it for a statement of Hume's own view; for discussion, see Butler, 'Vulgar Fiction', 243–44. 6 Hume often says that our impressions are 'of' things or qualities: for example, 'impression of a white colour' (T 1.1.7.18/25), 'impression of a curve or right line' (T 1.2.4.25/49), 'impression of 49 solid and tangible objects' (T 1.2.5.16/59). Following him, I will use this locution to talk about impressions. In doing so, I am not taking a stand on whether Humean impressions are representations of things or qualities. Some scholars argue that they are not, e.g. Rachel Cohon and David Owen, 'Hume on Representation, Reason, and Motivation', Manuscrito, 20 (1997), 47– 76, at 52–57. These scholars can interpret my use of the "impression of" locution, here and throughout this paper, as they interpret Hume's. (Presumably, when Hume says that an impression is 'of' a white color, these scholars take him to be saying that the impression has, or is an instance of, that white color. Similarly, when I say that all impressions are 'of' positive qualities, they can take me to be saying that all impressions have, or are instances of, such qualities.) 7 Scholars disagree about whether Hume's theory allows for ideas that represent what 'philosophers' (purport to) believe: see Don Garrett, 'Hume's Naturalistic Theory of Representation' ['Representation'], Synthese, 152 (2006), 301–19, at 305 and 316–17, who holds that it does; and Loeb, Stability and Justification, 162–72, who denies this. I take no stand on this issue here. 8 Some may object that, according to Hume, what is enlivened is a 'fiction', not an idea (T 1.4.2.42/209). However, the context makes clear that this fiction is an idea: earlier in the same paragraph, Hume writes that any imaginative propensity that gives rise to belief must 'convey the vivacity from the impression to the idea', and adds that 'this is exactly the present case' (T 1.4.2.42/208). In the next paragraph, he writes that the fiction in question 'is really false' (T 1.4.2.43/209). Truth and falsity are properties of ideas, in his view (T 2.3.3.5/415). So, this fiction is an idea. 9 See the studies cited in §2 and also: Henry E. Allison, Custom and Reason in Hume: A Kantian Reading of the First Book of the Treatise (New York: Oxford University Press, 2008), 234–46; A. 50 J. Ayer, Hume (New York: Hill and Wang, 1980), 39–51; Annette Baier, A Progress of Sentiments: Reflections on Hume's Treatise (Cambridge, MA: Harvard University Press, 1991), 108–22; Donald L. M. Baxter, 'Identity, Continued Existence, and the External World', in Saul Traiger (ed.), The Blackwell Guide to Hume's Treatise (Malden: Blackwell), 114–32; Jonathan Bennett, Learning from Six Philosophers, vol. 2 (New York: Oxford University Press, 2001), chapter 37; Mark Collier, 'Filling the Gaps: Hume and Connectionism on the Continued Existence of Unperceived Objects', Hume Studies, 25 (1999), 155–70; Georges Dicker, 'Three Questions about Treatise 1.4.2' ['Three Questions'], Hume Studies, 33 (2007), 115–53, at 137–47; Robert J. Fogelin, Hume's Skepticism in the Treatise of Human Nature (London: Routledge and Kegan Paul, 1985), chapter 6; Don Garrett, Hume (New York: Routledge, 2015), 97–100; P. J. E. Kail, Projection and Realism in Hume's Philosophy [Projection and Realism] (New York: Oxford University Press, 2007), chapter 1; Norman Kemp Smith, The Philosophy of David Hume (New York: Palgrave Macmillan, 1941), 469–85; Loeb, Stability and Justification, chapter 6; Ira M. Schnall, 'Constancy, Coherence, and Causality', Hume Studies, 30 (2004), 33–50; Eric Steinberg, 'Hume on Continued Existence and the Identity of Changing Things', Hume Studies, 7 (1981), 105–20; Stroud, Hume, chapter 5; John P. Wright, The Sceptical Realism of David Hume (Minneapolis: University of Minnesota Press, 1983), 59–74; and Wright, Introduction, 142–50. 10 Stroud writes that Hume 'has done little towards explaining the origin of the idea of continued existence' (Hume, 109). This is hardly fair: Hume spends pages explaining the mechanisms that produce this idea (T 1.4.2.20–22/195–98, 1.4.2.24–40/199–208). But I suspect Stroud really means that Hume does little to explain how this idea manages to represent its object as existing unperceived-a fairer complaint. 11 For variations on this theme, see Donald C. Ainslie, Hume's True Scepticism [HTS] (New York: 51 Oxford University Press, 2015), 47–56; Butler, 'Vulgar Fiction', 244; and Kenneth P. Winkler, 'Hume on Scepticism and the Senses', in Donald C. Ainslie and Annemarie Butler (eds.), The Cambridge Companion to Hume's Treatise (New York: Cambridge University Press, 2015), 135– 64, at 161–62n11. Similarly, Tim Black ('The Distinction Between Coherence and Constancy in Hume's Treatise I.iv.2' ['The Distinction'], British Journal for the History of Philosophy, 15 [2007], 1–25, at 19) distinguishes two forms of 'vulgar' belief, neither of which attributes unperceived existence to anything. However, elsewhere in his paper, Black suggests that the 'vulgar' do believe certain things to exist unperceived ('The Distinction', 16, 21). 12 See Butler, 'Vulgar Fiction', 242–45, on NO IDEA, and 245–46, on BELIEF®IDEA. Ainslie and Winkler have different motivations. Ainslie thinks his interpretation allows him to solve a puzzle about Hume's claim that continued existence entails distinct existence and vice versa (HTS, 44, 47–52). However, I find his proposed solution unsatisfactory; see my discussion of his (Cn) and (Dn), below. Winkler claims that Hume's argument in T 1.4.2.3/188–89 (summarized at T 1.4.2.11/191) suggests that the 'vulgar' belief does not represent anything as existing unperceived ('Hume on Scepticism and the Senses', 144, 161–62n11). Winkler does not analyze this argument in detail, so I am unsure why he thinks it supports this interpretation over the one I favor; for my own discussion of this argument, see §3 below. Winkler also cites T 1.4.2.38/207, where Hume writes that '[w]hen we are absent from it [i.e. a perception or object], we still say it exists' ('Hume on Scepticism and the Senses', 162n11). But Winkler's quotation omits two crucial clauses of this sentence, which, in full, reads: 'When we are absent from it, we still say it exists, but that we do not feel, we do not see it' (italics added). The italicized clauses, which Winkler omits, suggest that the 'vulgar' belief does represent an object or perception as existing unperceived-as not felt and not seen-contrary to his interpretation. 52 13 For example, see Edward Craig, The Mind of God and the Works of Man [Mind of God] (Oxford: Clarendon Press, 1987), 123–25; and Wilbanks, Imagination, 154–55. Relatedly, Galen Strawson ('David Hume: Objects and Power', in Rupert Read and Kenneth A. Richman [eds.], The New Hume Debate: Revised Edition [New York: Routledge, 2007], 31–51, at 39) claims that Hume posits 'suppositions' about things 'of which we have (and can have) no impression-copycontentful idea'. 14 Scholars often object that, while continued existence implies distinct existence, the converse implication does not hold (for example, Price, External World, 18–19). However, the claim that distinct existence implies continued existence plays no role in Hume's argument or in mine. For a defense of this claim that is congenial to my interpretation, see Dicker, 'Three Questions', 116– 24, and Stroud, Hume, 259n2; for a defense congenial to the view that Hume does not accept BELIEF, see Ainslie, HTS, 47–56. 15 Hume distinguishes two kinds of objects that can be regarded as existing at different moments: a 'succession' that genuinely has duration and a 'stedfast' object that has a 'fictitious duration' (T 1.2.3.6–11/34–37, 1.2.5.29/65); for helpful discussion, see Donald L. M. Baxter, Hume's Difficulty: Time and Identity in the Treatise (New York: Routledge, 2008), chapters 2–3. A succession exists at different moments by having a different temporal part located at each of them. Since different things exist independently of each other, in Hume's view (T 1.3.3.3/79–80), there is no necessary connection between a succession's existing at one moment (by means of one temporal part) and its existing at any other (by means of another temporal part). A steadfast object counts as 'fictitious[ly]' enduring by coexisting with each temporal part of a succession (T 1.2.5.29/65). Given that each of these temporal parts could exist without any of the others, the steadfast object could fail to count (even fictitiously) as existing at different moments. So, there is 53 no necessary connection between a steadfast object's existing at one moment and its existing (fictitiously) at any other. 16 There is a further reason for interpreting 'existence ... independent of ... the perception' as existence independent of being perceived, not as existence independent of perceptions. Hume attributes a belief in distinct existence to the 'vulgar' (T 1.4.2.14/193). But the 'vulgar' presumably do not think of things as perceptions. So, they do not suppose anything to exist independently of perceptions. And so, when Hume attributes to the 'vulgar' a belief in 'existence ... independent of ... the perception', he must mean a belief in existence independent of being perceived: that is, existence independent of being felt, being seen, and so forth. (For evidence that Hume's 'vulgar' do think of things as being felt and as being seen, see T 1.4.2.38/207.) 17 Simon Blackburn ('Hume and Thick Connexions', Philosophy and Phenomenological Research, 50 [1990], supplement, 237–50, at 240) may interpret the passage in this way: he writes that it 'affirms idealism'. 18 Thanks to David Landy for pressing me to consider this. 19 For the qualification 'as far as we can conceive it', see T Abs 28/656. 20 Butler, 'Vulgar Fiction', 243; Landy, Kant's Inferentialism, 34–35. 21 As Landy interprets Hume's argument in this passage, it invokes RCP rather than what Landy calls the Copy Principle; see note 5, above. 22 Garrett notes that Hume sometimes uses the phrase "the senses" in a broad way, to include the imaginative mechanisms responsible for our belief in body (Don Garrett, 'Loeb's "Standard" Questions about Hume's Concept of Probable Truth', Hume Studies, 40 [2014], 279–300, at 294– 95; see also Garrett, Hume, 97–98). However, when Hume argues argues that 'the senses' do not produce our ideas of continued and distinct existence (T 1.4.2.3–13/188–93), he must be using this 54 phrase in a narrower way that excludes these imaginative mechanisms-for he later claims that these mechanisms do produce our ideas of continued and distinct existence (T 1.4.2.36–40/205–8, 1.4.2.44/210). Quite rightly, Garrett does not include T 1.4.2.3–13 in his list of paragraphs where Hume uses "the senses" in the broad way. 23 Garrett argues that all Humean representation is explained by the 'causal and/or functional role' of that which represents, not by copying ('Representation', 307–17). However, Garrett should accept that, for Hume, every idea copied from an impression of shade S plays a causal and/or functional role sufficient for representing S (otherwise, it would be hard for him to make sense of Hume's claim that '[i]deas always represent the objects or impressions, from which they are deriv'd', T 1.2.3.11/37). 24 By "representational property", I mean property of representing such-and-such: for example, the property of representing Fido, the property of representing Fido as a dog, and the property of representing Fido as smaller than Rover are all representational properties, in my sense. For Hume, '[i]deas always represent the objects or impressions, from which they are deriv'd' (T 1.2.3.11/37; see also T 1.3.14.6/157). In his view, then, every idea-or, at least, every idea derived from an 'object or impression'-has at least one representational property, in my sense: namely, the property of representing this object or impression. 25 I thank Louis Loeb for help framing my opponents' position. 26 For brevity's sake, I omit this qualification in the rest of my discussion. 27 Don Garrett, Cognition and Commitment in Hume's Philosophy (New York: Oxford University Press, 1997), 21, 41; Landy, Kant's Inferentialism, 22–23. Similarly, Butler interprets the Copy Principle as stating 'that all simple ideas are ultimately caused by and resemble antecedently experienced impressions' ('Vulgar Fiction', 238). Presumably, she thinks this principle has 55 implications regarding what our simple ideas represent; otherwise, the argument for NO IDEA that she endorses would be invalid ('Vulgar Fiction', 242–43). 28 'Representation', 309. As evidence, Garrett claims that a pebble can represent a bridge in an impromptu military diagram without resembling or being caused by it; and that a decorative motif on a building need not represent the exactly similar motif on the building from which it is copied. His opponent might reply that the causal chains in these cases are deviant, hence these cases do not refute the view that being non-deviantly caused by and resembling something is sufficient for representing it. By adopting this view, Garrett's opponent could defend the second or third interpretation of the Copy Principle (below), on which this principle has implications about what our simple ideas represent-assuming that she could defend an account of the deviant/non-deviant contrast on which the causal relation that the Copy Principle concerns is non-deviant but those that Garrett describes are deviant. (I thank David Landy and Louis Loeb for discussion of deviant causal chains.) 29 Landy, Kant's Inferentialism, 26, 28, 31. 30 For Garrett's view of the connection between copying and representation, see 'Representation', 311–13; for Landy's, see Kant's Inferentialism, chapter 1. 31 For evidence that the relevant kind of 'derivation' is causal, see Hume's argument for this part of the Copy Principle at T 1.1.1.8–9/4–5. See also T 1.1.1.11/6–7, where he equates being produced by, being derived from, and proceeding from. 32 In the neighboring paragraphs, Hume uses the language of "correspondence" and "resemblance" interchangeably: for example, he writes that 'every simple idea has a simple impression, which resembles it; and every simple impression a correspondent idea' (T 1.1.1.5/3; see also T 1.1.1.8/4). So, for Hume, saying that every simple idea is correspondent to a simple impression seems to 56 mean that every simple idea resembles a simple impression. 33 However, Hume also holds that only a complex idea can represent a relation (T 1.1.4.7/13). So, only a complex idea can represent its object as being perceived. This view commits him to saying that no simple idea represents its object as being perceived, but not to saying that no simple idea represents its object as being unperceived-he could consistently accept the former while denying the latter. (In fact, I think he should do so: the account of negation that I offer him in §5 allows that a simple idea can represent its object as being unperceived, even though no simple idea can represent its object as being perceived.) 34 The text may seem to allow a stronger interpretation: that "exactly" means completely and accurately. If this stronger interpretation is correct, then Hume is committed to NO SIMPLE IDEA: every simple impression is perceived; so, if every simple idea is a complete and accurate representation of its object, then every simple idea represents its object as perceived; but no idea can represent its object both as perceived and as unperceived; and so, we do not have (at our disposal) a simple idea that represents its object as unperceived. However, the stronger interpretation of the Copy Principle cannot be correct. Being perceived is a relation. In Hume's view, only complex ideas can represent relations (T 1.1.4.7/13). So, no simple idea can represent its object as perceived. And so, no simple idea is a complete representation of its object, in the sense that this argument requires: that is, no simple idea represents its object as having all the properties and as standing in all the relations that its object does. (I thank Louis Loeb for suggesting that I consider the stronger interpretation of the Copy Principle.) 35 Suppose that the idea did not predicate anything of its object, but merely picked it out or referred to it, as a bare demonstrative like "this" or "that" picks out its referent. It could then be neither true nor false. 57 36 This interpretation of the Copy Principle corresponds to part of what Landy calls the Representational Copy Principle (see note 5, above), which implies that every simple idea is an accurate representation of the impression from which it is copied (2015: 42–43). The other part of the Representational Copy Principle concerns complex ideas (2015: 43–48). 37 Similarly, Karl Schafer sees Hume as distinguishing two species of representation ('Hume's Unified Theory of Mental Representation' ['Unified Theory'], European Journal of Philosophy, 23 [2015], 978–1005). The two species are: (i) 'imagistic' representation of intrinsic qualities, which is explained wholly by copying, hence is custom-independent in my sense ('Unified Theory', 991); (ii) non-'imagistic' representation of extrinsic 'formal, relational or structural features', which is explained by associations among ideas ('Unified Theory', 996). Schafer stresses that, at least in central cases of (ii), the relevant associations result from 'linguistic conventions or customs', hence these cases are custom-dependent in my sense ('Unified Theory', 992). Schafer's motivations include both the need to square passages where Hume holds that copying is necessary and sufficient for (some sort of) representation, e.g. T 1.2.3.11/37 and T 1.3.14.11/161, with passages where he holds that association contributes to explaining representation, e.g. T 1.1.7.7– 10/20–22; and the philosophical consideration that any satisfactory theory of representation must be explain to explain how ideas represent both intrinsic and extrinsic properties. 38 I use double quotation marks when mentioning a word or phrase, rather than using or quoting it. (When quoting, I use single quotation marks.) 39 Scholars disagree about whether general terms are essential to Hume's account of abstract or general ideas. Wayne Waxman argues that non-linguistic animals could have the relevant customs: see his Hume's Theory of Consciousness (New York: Cambridge University Press, 1994), 105– 11. Others argue that these customs require mastery of a general term: see Ainslie, HTS, 65; Karl 58 Schafer, 'The Artificial Virtues of Thought: Correctness and Cognition in Hume', Philosophers' Imprint, forthcoming, available online at <https://webfiles.uci.edu/schaferk/www/ArtificalVirtuesCognition-IMPRINTFINAL.pdf> (retrieved August 31, 2018); and my 'A Puzzle about Fictions in the Treatise', Journal of the History of Philosophy, 54 (2016), 47–73, at 56n23. Here, I assume the latter view is correct. However, scholars who disagree can accept that some representation is custom-dependent; they should substitute their own preferred account of the relevant customs. 40 For this general problem and proposed solutions to it, see Lewis Powell, 'Hume's Treatment of Denial in the Treatise' ['Denial'], Philosophers' Imprint, 14 (2014), 1–22, at 14–16 (who offers two different solutions) and Garrett, Hume, 75–77; I discuss these solutions in §6, below. 41 Derek R. Brookes (ed.), An Inquiry into the Human Mind on the Principles of Common Sense [Inquiry] (Edinburgh: Edinburgh University Press, 1997), 30. 42 Reid, Inquiry, 30. 43 See also Stroud, Hume, 75–76. 44 For variations on this point, see Garrett, Hume, 75; Powell, 'Denial', 4–6; and Stroud, Hume, 75. Reid seems to have assumed without argument that Hume cannot allow for ideas that differ representationally in this way: he writes that the ideas of both a proposition and its contrary 'according to Mr. HUME, are the same' (Derek R. Brookes and Knud Haakonssen [eds.], Essays on the Intellectual Powers of Man [University Park: Pennsylvania State University Press, 2002], 292). Perhaps Reid thinks it obvious that if all simple impressions are positive, and all simple ideas are copied from simple impressions, then no idea can represent negation. 45 For a different argument to the same conclusion, see Stroud, Hume, 75. For helpful discussion of Stroud's argument and a response to it, see Powell, 'Denial', 12–14. 59 46 In this respect, ideas differ from the symbolic representations found in today's propositional and predicate logics. In these logics, only a complex symbol (formed from the negation operator and a symbol for the negated proposition) can represent an instance of negation. 47 Compare Garrett, Hume, 76. For discussion of Garrett's views on negation, see §6, below. 48 Here, I follow Garrett, Hume, 77, and Powell, 'Denial', 19–20. 49 In the first Enquiry, Hume claims that contrariety may be 'considered as a mixture of causation and resemblance' (E 3.16n6/24n4). This view seems different from the Treatise's (for this point, see Powell, 'Denial', 20n41); I do not claim that the account I have offered Hume is consistent with it. 50 In Hume's view, some but not all perceptions are spatially located (T 1.4.5.10/235–36). 51 Some scholars would deny that this is a complete account of how we think of things (in this case, an impression and a mind) as causally related, in Hume's view. Some would add that thinking of things as causally related involves 'projecting' necessity onto them. For example, see Stroud, Hume, Chapter 4; for sophisticated 'quasi-realist' developments of this view, see Blackburn, 'Hume and Thick Connexions', and Angela Coventry, Hume's Theory of Causation: A QuasiRealist Interpretation (New York: Continuum, 2006), chapter 5. Others would add that such thinking is not just a matter of having ideas, but also involves a 'supposition' (Craig, Mind of God, chapter 2; Galen Strawson, The Secret Connexion: Causation, Realism, and David Hume [Oxford: Clarendon Press, 1989], chapter 12) or a 'thin notion' of causal power (Kail, Projection and Realism, chapters 4–5). Nothing here turns on this issue: I require only that we can somehow think of an impression and a mind as being causally related in the way Hume describes at T 1.4.2.40/207– 8, and thereby think of that impression as being perceived. The reader can substitute his or her own preferred account of what such thinking involves. 60 52 Concerning our 'vulgar' ways of speaking about unperceived objects, Hume says: 'When we are absent from it [i.e. the perception or object], we say it still exists, but that we do not feel, we do not see it' (T 1.4.2.38/207). 53 According to some scholars, Hume holds that thinking of things as causally related is not just a matter of having ideas that represent them (see note 51, above). They can accept the following, modified version of my proposal: an idea represents a furniture-impression as not being perceived, when i) it represents that furniture-impression, ii) its subject does not think of that furnitureimpression as being perceived, and iii) it is associated with a linguistically mediated custom whereby thinking of that furniture-impression as being perceived (whatever such thinking involves) is disallowed. 54 I thank Eric Hiddleston for this challenge. 55 On this account, acquiring the relevant custom essentially involves acquiring mastery of a word or phrase. Readers who think such mastery inessential to the customs Hume posits, when explaining categorial and abstract representation, can substitute their own preferred account of how we acquire such customs. (See note 39, above.) 56 Powell, 'Denial'; Garrett, Hume, 75–77. 57 Powell notes that Donald Baxter and Don Garrett suggested this proposal to him ('Denial', 14n33). Garrett has since developed it differently (Hume, 75–77); for discussion, see below. 58 Of course, thinking of Dumbo's nonexistence need not involve thinking that the world is full of chocolate pudding. Powell accommodates this point by positing an abstract idea ('Denial', 16). Suppose that we associate all and only our ideas that crowd out Dumbo with a common general term-say, "Dumbo-less". Hearing this term will subsequently cause us to form an idea that crowds out Dumbo and revive our custom of surveying all and only other ideas that crowd out 61 Dumbo (including our idea of the pudding-filled world). Under these circumstances, Powell proposes, the abstract idea that we form represents Dumbo's nonexistence. 59 For this point, see Garrett, Hume, 76. 60 Strictly speaking, this is Garrett's account of how a mind may represent negation 'nonconceptually,' that is, without using abstract ideas (Hume, 76). Non-conceptually, we can represent only particular instances of negation: for example, my living room furniture's not now being perceived by me. Representing general negative kinds-for example, all unperceived furniture- requires an abstract idea, and is therefore an example of what Garrett calls 'conceptualized' representation (Hume, 77). For Hume, non-conceptual representation is explanatorily prior to conceptualized or abstract representation. I therefore focus on the contrast between Garrett's and my accounts of how negation is represented 'non-conceptually'. 61 I thank Hartry Field and Daniel Fogal for raising this issue. 62 I thank Don Garrett, Eric Hiddleston, and Louis Loeb for much help with this section. 63 For example, see Butler, 'Vulgar Fiction', 237; Kemp Smith, The Philosophy of David Hume, 453; and Waxman, Hume's Theory of Consciousness, 247. 64 Butler claims that animals lack 'abstraction' ('Vulgar Fiction', 237). If this is correct, it is presumably because they lack the relevant customs. 65 I thank Louis Loeb for helping me see this. 66 This paper descended from a chapter of my dissertation, which itself descended from a talk. For help with the chapter, I thank Ralf Bader, David James Barnett, Ned Block, David Chalmers, Shamik Dasgupta, Kit Fine, Laura Franklin-Hall, Don Garrett, Béatrice Longuenesse, Colin Marshall, Tim Maudlin, John Morrison, Lewis Powell, Hsueh Qu, John Richardson, Karl Schafer, Jonathan Simon, James Stazicker, Peter Unger, David Velleman, Kenneth Winkler, and audiences 62 at meetings of the NYU Thesis Preparation Seminar and the Washington Square Circle. Research on the chapter was supported by an ACLS/Mellon Dissertation Completion Fellowship; I thank the ACLS and the Andrew W. Mellon Foundation. For feedback on the talk, I thank audiences at the NYU Humanities Initiative and the 2011 Pacific APA meeting, and especially Donald Ainslie, who was my commentator at the APA. For feedback on more recent drafts of this paper, I thank Ryan Fanselow, Don Garrett, Eric Hiddleston, Katherine Kim, David Landy, Colin Marshall, Hsueh Qu, Mike Raven, Donald Rutherford, Sean Stidd, Josh Wilburn, and an audience at the University of Washington. Special thanks to a once-anonymous referee whom I now know to be Louis Loeb, for much valuable criticism and advice.