Andrew Chignell Real Repugnance and our Ignorance of Things-in-Themselves: A Lockean Problem in Kant and Hegel Kant zufolge muss ein Subjekt, um Wissen von einem Objekt zu erlangen, in der Lage sein zu „beweisen", dass das Objekt real möglich sei, d.h. zu beweisen, dass es zwischen seinen Eigenschaften weder eine logische Inkonsistenz noch einen „realen Widerspruch" gebe. Dies ist zwar (gewöhnlich) einfach im Hinblick auf empirische Objekte, aber im Hinblick auf einzelne Dinge an sich selbst (gewöhnlich) unmöglich zu erfüllen. Im ersten Abschnitt des Aufsatzes zeige ich, dass sich eine Version der Kantischen Auffassung bezüglich unserer Unwissenheit hinsichtlich der realen Möglichkeit – sowie eine Version seiner Antwort darauf – bereits in Lockes Essay findet. Im zweiten Abschnitt diskutiere ich die Art und Weise, in der diese „modale Bedingung" zumindest zum Teil Kants berühmtes Verdikt gegen die Erkenntnis von Dingen an sich selbst motiviert. Im letzten Abschnitt untersuche ich Hegels Versuche, das Problem des realen Widerspruchs zu lösen und dadurch ein überkommenes Hindernis für das spekulative Wissen vom Übersinnlichen zu beseitigen. Why can't we have theoretical knowledge of the positive properties of particular things-in-themselves? The question is harder to answer on Kant's behalf than it initially seems. Prominent attempts in the secondary literature include: because our concepts don't apply to such things in a knowledge-producing way; because things-in-themselves aren't "given" in intuition and such givenness is required for knowledge of their positive properties; because things-inthemselves are the objects of merely regulative ideas; because at least some of the things-in-themselves are transcendentally free and thus theoretically unknowable; because things-in-themselves are mind-independent and we can only theoretically know mind-dependent objects; because knowing a thing-in-itself involves knowing its intrinsic properties and our theoretical faculties cannot access those.1 The answer to the question that I consider here is conceptually distinct from each of these, albeit importantly related to some of them. It goes by way of the following brief argument: 1 Discussions of this question are pervasive in the secondary literature, including Adickes, 1924; Prauss, 1974; Guyer, 1987; Ameriks, 1992; Adams, 1997; Langton, 1998; Grier, 2001; Hogan, 2009; and Watkins, 2009. 1. Our theoretical faculties cannot reliably track the "real" or metaphysical modality of things without appealing to facts about experience. 2. Thus, we have no way to prove that supersensible things are really possible. 3. But being able to prove that something is really possible is a necessary condition of having theoretical knowledge of its positive properties. 4. Thus, we can have no theoretical knowledge of the positive properties of particular things-in-themselves. This answer to the initial question is not – or not obviously – inconsistent with any of the alternative answers surveyed in the last paragraph. My suspicion is that it is more fundamental than any of those alternatives, and that it may motivate some of them, but I won't try to defend that suspicion here. It is unclear (to me at least) whether this is Kant's most fundamental answer to the question: there may be more to say about why our faculties do not reliably track real modality or about why proof of real possibility is required for knowledge in the first place. But if this is one of Kant's answers to our important initial question, then why has it been so neglected by commentators? The best explanation, I think, is simply that Kant offers numerous different accounts of our ignorance of things-in-themselves and typically leaves the relations between these accounts woefully obscure. Thus, what I take to be the deep worry about our inability to prove the real possibility of supersensible things is often articulated as a concern about the reference or content of the transcendental ideas that we have of such things or about the ability of our concepts to apply to such things. Let me briefly elaborate this last point. Readers of the critical philosophy will know that Kant often wonders how we can be justified in taking ideas of freedom, the soul, noumenal grounds, God, and supersensible things-in-themselves generally to have "objective reality" in the absence of an appropriate connection to experience. How can we be sure, Kant asks, that these ideas are not just incoherent "thought-entities" (Gedankendinge) conjured up by mere speculative fancy (A771/B779)? It is natural to take this to be a concern about semantics and/or conceptual content. When we look closely, however, we find that this problem about the content of ideas – about how to ensure that they have "objective reality" and aren't merely "empty" – is often closely connected (or perhaps even equated) by Kant with the problem of showing that the object of such an idea is really – and not just logically – possible.2 To show that an 136 Andrew Chignell 2 This discussion is complicated by the fact that Kant uses "objective reality" in a maddeningly loose fashion: sometimes it means that the relevant concept or idea has an actual instance (Kant, 1902, Practical, 5, p. 5; Lectures on Religion, 28, p. 1015); sometimes it means merely that an instance is logically possible (Practical, 5, p. 54); but typically it means that an instance is really possible, and that's how I use it here. Adding to the confusion is the fact that Kant often says that knowledge of real possibility is inferred from knowledge of actuality (cf. Kant's discussion in the Postulates object is really possible, Kant says, is tantamount to showing that there is neither logical contradiction nor "real repugnance" between the predicates contained in its concept, and that at least some of those predicates have positive content. And the reverse is also true: to show that a concept possesses positive, really harmonious content (i.e., that it has "objective reality" and is not "empty") is just to show "that an object corresponding to it is possible" (dass ihm gemäss ein Object möglich sei) (Judgment 5, p. 396).3 "Real repugnance" in this context refers to the metaphysical analogue of logical inconsistency: it is a non-logical kind of opposition that makes a concept incoherent and its object impossible. Real harmony is just the absence of real repugnance.4 Clearly there are systematic questions to ask about the putative connections between these two problems – i.e., the problem of acquiring "objective reality" for ideas and the problem of establishing the real possibility of their objects.5 The focus of the present paper, however, is more descriptive and historical. It is easy to get (or give) the impression that Kant was the first major philosopher (a) to clearly distinguish between logical and "real" modality and (b) to use that distinction as a basis for skepticism about certain things, their properties, or both. In section A below, I argue, to the contrary, that an important predecessor of Kant's account can be found in John Locke's Essay Concerning Human Understanding, and that Kant is actually articulating a broadly Lockean position when he says that our inability to prove the real possibility of certain things means that we cannot have any determinate theoretical knowledge of their positive properties. Of course, the critical philosophy does seek to improve on Lockean empiricism by securing substantive a priori knowledge about appearances and by employing a principled transcendental method – as opposed to Locke's empirical-physiological one – to determine where the boundaries of human knowledge lie. And though Kant follows Locke in making room for faith or "belief" (Kant's term is "Glaube") about certain things after having denied that we can have theoretical knowledge of them, he also finds the threat of real repugnance so worrisome that he goes on to offer three different accounts of how the supersensible objects of belief, too, might be regarded as (though not proved to be) really possible. In section B of the paper, I lay out Kant's version of the problem A Lockean Problem in Kant and Hegel 137 at A231–2/B284). But this epistemic point should not lead to a conceptual collapse: real possibility and actuality are still importantly distinct, as we will discover below. 3 Texts that establish this connection between the objective reality of a concept and the real possibility of its object include B270/A223, B292–3; Practical, 5, p. 134; "On a Discovery," 8, p. 191; Real Progress, 20, p. 266. 4 For discussions of real repugnance, see "Negative Magnitudes" 2, pp. 172–175; "On a Discovery," 8, p. 240; Real Progress, 20, pp. 283, 299; and Lectures on Religion, 28, p. 1016. 5 See Chignell, 2010 for more discussion of these questions. of real repugnance, show how his appropriation of the Lockean constraint underwrites the famous prohibition on knowledge of things-in-themselves, and sketch his three solutions to the problem as it relates to belief. The final section of the paper (section C) traces the story further by showing how Hegel – as unhappy with the distinction between appearances and thingsin-themselves as he is with skepticism in general – effectively dissolves the problem of real repugnance in order to allow for speculative knowledge of the "absolute." Hegel argues that the only coherent conception of real possibility takes into account all of the conditions that a thing would have to satisfy in order for it to be actual, and thus that the only things that are really possible – demonstrably so – are also actual. Thinking in terms of "mere possibility," on the other hand, is just a misleading way of abstracting from the "richer and more comprehensive determination" of the actual absolute that is the proper object (and subject) of speculation (Hegel, 1991, EL § 143, Zusatz, p. 216). Hegel thus denies the Lockean-Kantian assumptions that there is an isolable sphere of real modality between the logical and the causal, and that our inability to track the contours of that sphere should lead to agnosticism about certain things. Of course, Hegel still needs an independent story about how the mind acquires access to the absolute. But by dissolving the problem of real repugnance in this way, he can regard himself as removing a prominent inherited obstacle to speculative knowledge-claims about ultimate reality.6 A. A Problem from Locke Book 4 of Locke's Essay contains a lengthy discussion of human knowledge and the other attitudes and "enthusiasms" that aim (for better or for worse) to go beyond our epistemic limits. Although his conclusions draw on earlier doctrines regarding the origins of our ideas, it is in Book 4 that Locke clearly expresses the claim that mere "conceiving" (i.e., merely entertaining and analyzing ideas) does not reliably track what Kant will call the "real possibility" of substances. It is also where he explicitly lays out the skeptical implications of this part of his theory. Two consecutive chapters in Book 4 are of central importance: the first is the chapter on "The Extent of Humane Knowledge" (E 4.3); the second is "The Reality of Knowledge" (E 4.4).7 In the first of these, Locke claims that we can intuitively "perceive" which of our ideas agree or disagree with one another as a 138 Andrew Chignell 6 Whether he does so regard himself is another story, perhaps. I'm not sure whether Hegel explicitly recognized the Lockean-Kantian requirement to prove real possibility as one that he had to deal with in order to safeguard speculative knowledge-claims (though I do provide a few suggestive texts below in that connection). 7 Though see also E 4.5 and E 4.8 for other relevant passages. matter of logical necessity and that we can learn through empirical experience which other ideas empirically "coexist" as a matter of fact. What we cannot learn, with respect to the latter, is whether the qualities that cause those ideas are metaphysically connected, or whether their constant "co-existence" is mere happenstance. Conversely, we cannot learn from either reflection or experience whether the fact that logically consistent ideas are empirically "in-coexistent" (Locke's term) is grounded in the natures of the causes of those ideas or whether this fact too is merely contingent (E 4.3.12). Regarding a substance like gold, for example, "'tis impossible we should know what other Qualities result from, or are incompatible with the same Constitution of the sensible parts of Gold; and so consequently must always co-exist with that complex Idea we have of it, or else are inconsistent with it" (E 4.3.11).8 On the basis of these observations, Locke concludes that we typically know which qualities can be exemplified together in substances just in case we experience them actually so exemplified through the simple ideas that they cause in us. With respect to ideas of qualities that we don't experience in this way, he reiterates, "tis but in a very few cases, we can be able to perceive their dependence on, or repugnance to any of those Ideas, which make our complex one of that sort of Thing."9 Again, cases in which we are able to perceive dependence or repugnance are typically cases involving logical entailment or contradiction (E 4.3.14–15; cf. Locke 1823, vol. 4, p. 465). Extra-logical, metaphysical relations between such qualities in substances, by contrast, are largely inaccessible to both thought and experience (E 4.3.16).10 A Lockean Problem in Kant and Hegel 139 8 In passages like this, Locke uses both "incompatible" and "inconsistent" to refer to the relation that Kant will call "really repugnant." Locke sometimes refers to it as "repugnancy to co-exist" (4.3.15), but, as far as I know, he doesn't put the terms "real" and "repugnant" together in precisely the way Kant does. In what follows I will often insert "logical" in brackets to indicate where I think Locke is talking about logical rather than real repugnance. 9 Recall that Locke uses "perception" to refer to intellectual awareness generally – "it is called by some Thinking in general" (E 2.9.1). 10 I insert the qualifiers "typically" and "largely" here because Locke sometimes suggests that we perceive at least a few metaphysical connections between ideas: "Figure necessarily supposes Extension," for example, and "receiving or communicating Motion by impulse supposes Solidity" (E 4.3.15–16). A few real repugnancies may also be "visible" to mere conception: for example, "that any Subject can have of each sort of primary Qualities, but one particular at once, v.g. each particular Extension, Figure, number of Parts, Motion, excludes all other of each kind." Something similar is said of secondary qualities (ibid.). In a later chapter on "Trifling Propositions," moreover, we're told that "we can know the Truth, and so may be certain in Propositions, which affirm something of another, which is a necessary consequence of its precise complex Idea, but not contained in it. As that the external Angle of all Triangles, is bigger than either of the opposite internal Angles; which relation of the outward Angle, to either of the opposite internal Angles, making no part of the complex Idea signified by the name Triangle, this is a real Truth, and conveys with it instructive real This doubt about the "extent" of our knowledge of finite substances reappears in the chapter on the "reality" of knowledge (E 4.4). Locke begins by considering a hypothetical objector who says that Locke goes astray in limiting us to perception of identity, "coexistence," and other relations between ideas. Of what use, asks the objector, "is all this fine Knowledge of Men's own Imaginations, to a Man that enquires after the reality of Things? It matters not what Men's Fancies are, 'tis the Knowledge of things that is only to be prized [...]" (E 4.4.1). Locke responds by first agreeing that knowledge is of great value when it "conforms" to the reality of things. The question, of course, is that of the "Criterion": "How shall the Mind, when it perceives nothing but its own Ideas, know that they agree with Things themselves?" (E 4.4.3). Part of Locke's answer is that simple ideas are not innate to the mind itself (cf. Book 1), and thus that they do tell us something about the powers that things have to produce ideas in us. Our simple ideas of whiteness and bitterness, for instance, conform to the power in a body to produce them, and this conformity, says Locke, is "sufficient for real Knowledge." In other words, we know, of the real substance, that it exists and has powers to produce simple ideas of whiteness and bitterness (E 4.4.4).11 These powers are then judged to consist in various qualities of "Bulk, Figure, Number, Texture, and Motion" that we are led by experience (together with some inferential extrapolation from the macrophysical to the microphysical) to ascribe to the "insensible parts" of bodies (E 2.21.73).12 With respect to knowledge involving the complex ideas that arise through combination and abstraction, Locke takes two different tacks in response to the hypothetical objector. The two tacks correspond to two distinct classes of complex general ideas: ideas of mixed modes and relations, on the one hand, and 140 Andrew Chignell Knowledge." (E 4.8.8) Here it looks as though Locke is explicitly affirming that we can perceive various extra-logical, necessary connections between qualities (but note that these are no longer qualities of substances). This is interesting and controversial material, but in any case it is clear, apart from these few exceptions – if they are indeed exceptions – that Locke thinks we have no knowledge of real dependencies and real repugnancies in substances. 11 Thus "conform" here must be interpreted not as "resembles" but rather as something like "indicates." See Newman, 2004 for discussion. 12 I use "judged" here because Locke seems ambivalent about whether to count the ascription of primary qualities to microscopic bodies as "real Knowledge." In the passage from Book 2 just quoted he says that "we cannot conceive" of the causes of our ideas as anything but the primary qualities of bodies. This of course leaves open the question of whether our conception is misleading. In Book 4, Locke says that our perception of secondary qualities in bodies is caused either by the primary qualities "of their minute and insensible parts" or by "something yet more remote from our Comprehension" (E 4.3.11). The latter is presumably the "uncertain philosophical cause" that he speaks of elsewhere as responsible for ideas of primary and secondary qualities alike. For discussion here, see Guyer, 2008 and Downing, 2008. ideas of substances, on the other. Regarding the first, Locke claims that the "archetypes" to which the knowledge conforms are simply our own complex general ideas of mixed modes or relations, and thus the judgments involved express "general Propositions, and notions in which Existence is not at all concerned" (E 4.4.8). In Book 2, we are told that although we may get such ideas by abstracting from experience, we can also simply construct them out of simple ideas ourselves or inherit them through language (E 2.22–25). Still, our perception of agreement and disagreement between these ideas of modes/relations constitutes significant "general knowledge" that is important for science (in the sense of scientia), even if those modes/relations aren't exemplified by actual substances (E 4.4.5). As examples of this, Locke cites our knowledge that the three angles of a triangle are equal to two right-angles and that "murder deserves death." If there are any triangles or murderers in the actual world, then they will of course have the properties ascribed to them in these propositions. The knowledge itself is not of existing substances, however, but rather of our ideas of modes and relations. Clearly this is how Locke hopes to vindicate claims to a priori knowledge in mathematics and ethics: the archetypes of such knowledge are just complex general ideas and the relations between them, so there is no need to look to the world for justification (E 4.4.6–8). Second, there are complex ideas that we generate in mere thought or conception, and whose "archetypes" are substances or kinds of substances outside us. Regarding these Locke is willing to concede much more to the hypothetical objector. Such ideas play an important role in natural philosophy, he says, but though they are "supposed taken from the Works of Nature, [they] may yet vary from them, by having more or different Ideas united in them, than are to be found united in the Things themselves: From whence it comes to pass, that they may, and often do, fail of being exactly conformable to Things themselves" and thus fail to count as knowledge (E 4.4.11). Locke's worry about lack of "conformity" here is grounded in the fact that when we generate theories involving complex general ideas of substances, we risk error if we do what we often do with complex general ideas of modes – namely, "put together such Ideas as have no [logical] inconsistence, though they did never before so exist." That in turn is because "our ideas of Substances being supposed copies, and referred to Archetypes without us, must still be taken from something that does or has existed; they must not consist of Ideas put together at the pleasure of our Thoughts, without any real pattern they were taken from, though we can perceive no [logical] inconsistence in such a Combination" (E 4.4.12). But why is there this risk? Why does Locke find it unacceptable to generate complex ideas of substances and, seeing no logical "inconsistence" among their predicates, simply assume that these ideas refer to possible objects or kinds of objects that can, in turn, be postulated by our best explanatory theories? A Lockean Problem in Kant and Hegel 141 The reason whereof is, because we knowing not what real Constitution it is of Substances, whereon our simple Ideas depend, and which really is the cause of the strict union of some of them one with another, and the exclusion of others; there are very few of them that we can be sure are, or are not inconsistent in Nature, any farther than Experience and sensible Observation reaches. (ibid., my emphasis) The "inconsistency in Nature" referred to here is clearly very close, I think, to what Kant will call "real repugnance." The claim is that even if we did know all of the logical relations involved, we still wouldn't know which qualities of substances are really dependent on, compatible with, or repugnant to other qualities without looking to experience. Locke's ultimate concern here, then, is that mere speculation and hypothesis traffic in ideas of quality-combinations that may, for all we know, be really impossible. If "real knowledge" is our goal, we have to forestall such trafficking by having prior assurance that quality-combinations are really possible before we postulate substances containing them. Given the limits on our powers of conception, such assurance can only be acquired, according to Locke, via experience. In short: real knowledge of substances involves complex general ideas that are "such and such only as are made up of such simple ones, as have been discovered to co-exist in Nature" (E 4.4.12, my emphasis). This clearly amounts to a serious constraint on speculation, as well as on theoretical knowledge of substances generally. That said, once we have learned from experience that two or more simple ideas go together in the complex idea of a substance, "these we may with confidence join together again, and so make abstract Ideas of Substances" (E 4.4.12). For example, if we have already perceived something that is both yellow and malleable, then we can reasonably generate complex ideas of kinds of things that conjoin these qualities and use them in our theories: "For whatever have once had an union in Nature, may be united again" (ibid.). This makes it clear that the uniformity of Nature is not the real worry for Locke; rather, the worry in this chapter, as in the previous one, is that we cannot know a priori whether a given combination of qualities is really possible, and that, conversely, no experience of "co-existent" qualities in nature proves that their connection is really necessary (E 4.3.13; cf. E 4.3.28). It is worth noting in this connection that at the time that Locke was composing the Essay, strict mechanistic models (with their no-action-at-a-distance principles) were being undermined by Newton's highly successful physics (with its gravitational principle). In the 1685 draft of the Essay (now referred to as "Draft C"), Locke seemed willing to assume that a suitably sophisticated mechanistic theory would be able to capture the truth about primary qualities and the real essences of bodies. In the first published edition of the Essay (1689), however, he backs away from this assumption and says merely that strictly mechanistic physics provides our best hypothesis about the natures of bodies and that as a result our concepts of kinds pick out merely "nominal" essences that may not correspond to the real essences of substances. In the revised fourth 142 Andrew Chignell edition of 1700, Locke goes further and deletes an argument for the conclusion that action at a distance is impossible, replacing it with the weaker claim that mechanistic contact impulse is "the only way which we can conceive Bodies operate in" (E 2.8.11, my emphasis).13 These changes appear to reflect Locke's awareness of Newton's successes, as well as his related suspicion that there may be "dependencies" and "repugnancies" in nature that go beyond anything dreamt of in our philosophy. Strictly mechanistic science, we're told, cannot explain "coherence and continuity of the parts of Matter" or body-mind causation; indeed, the explanation of such phenomena may lie in God's "superaddition" of qualities to bodies in ways that we can neither perceive nor conceive (E 4.3.28–29; cf. E 4.3.6). As a result, we must be skeptical of all claims involving quality-combinations that we don't independently know to be possible by way of independently knowing that they are actual.14 Interestingly, Locke places no such constraint on what he variously calls "right Judgment," "Opinion," "Belief," "Assent," and "Hypothesis" (E 4.14– 15).15 His surprisingly permissive attitude in that regard is offset by stern insistence that such attitudes cannot constitute the kind of scientific knowledge that is our ultimate goal. Kant, by contrast, thinks that we need some sort of solution to the problem of real repugnance even for belief (Glaube) if the latter is to count as rationally acceptable. No doubt this is partly a result of the fact that belief plays a much more important role in Kant's philosophy than it does in Locke's. B. The Problem Appropriated by Kant B.1. A Modal Condition on Knowledge Locke's modal epistemology is very different from Leibniz's, of course, and it is noteworthy that in the New Essays Leibniz skips over the passages just discussed in near-complete silence. Leibniz conceives of modal facts and predicates as fundamentally logical, which means that a suitably skilled logician would be A Lockean Problem in Kant and Hegel 143 13 For more on this development, see Downing, 2008, pp. 104–5. 14 On the claim about the inconceivability of certain relations and the "superaddition" of qualities by God, see Locke's letter to Stillingfleet of 1698; Locke, 1823, vol. 4, pp. 467–68 as well as the discussions in Wilson, 1999 and Downing, 2008, pp. 109 ff. 15 "Probability is likeliness to be true, the very notion of the Word signifying such a Proposition, for which there be Arguments or Proofs, to make it pass or be received for true. The entertainment the Mind gives this sort of Propositions, is called Belief, Assent, or Opinion, which is the admitting or receiving any Proposition for true, upon Arguments or Proofs that are found to persuade us to receive it as true, without certain Knowledge that it is so" (E 4.15.3). able to generate a complete list of all possible quality-combinations. Since for Leibniz "there are as many possible worlds as there are series of things that can be conceived that do not imply a contradiction," a logically omniscient being would also know everything about all the possible worlds (Leibniz 1948, vol. 1, p. 390). In some works, however, Leibniz modifies this picture slightly by appealing to what he calls "hypothetical" or "moral" modality. In the essay "On Freedom and Possibility" from the early 1680's, as well as in the Theodicy published much later, logic provides the guidelines for generating ideas of possible things and possible worlds, but value considerations place substantive constraints on which worlds count as "morally" possible (cf. Leibniz 1989, pp. 19 ff.; Leibniz 1875–90, pp. 235–237, 367). Given the necessary existence of the supremely good actualizer of worlds, says Leibniz, we have a priori grounds for thinking that only the best world is really, morally possible. Put another way: although many worlds are "internally" or "per se" possible, only the best world is "externally" compatible with the necessary existence of an omni-benevolent Creator. Whether the value constraint here can be articulated in logical terms – and, if so, whether Leibniz can ultimately avoid necessitarianism – is a matter of significant controversy. Kant was familiar with the Leibnizean picture, of course, but he was also deeply influenced by his Pietist predecessor Christian August Crusius – a prominent libertarian anti-rationalist who was himself a devotee of Locke. As early as the 1760's, Kant sought to revive a robust metaphysical distinction between "logical" and "real" modality, and throughout his career he harshly criticizes the Leibnizeans for neglecting its importance.16 In the "Negative Magnitudes" essay of 1762, for instance, Kant cites numerous examples of a kind of real repugnance between two or more properties that "cancels out" (the verb here is "aufheben") those properties' effects: opposing winds on a sail, opposing physical forces, opposing volitions, and so forth. In that essay, as well as in The Only Possible Basis essay of the following year, Kant also makes room for a kind of real repugnance that is subject-canceling – i.e., such that any being possessing it is rendered really impossible (and thus "aufgehoben"). Qualitycombinations such as being material and thinking, for example, or being a supreme being and being pleased by something outside oneself are said to be real repugnancies that cancel out not just one another, but also their subject as a whole (2, pp. 200–1; see also Metaphysical Foundations 4, p. 494 and "On a Discovery," 8, p. 240). Despite this difference in modal metaphysics, in 1763 Kant still models his modal epistemology on Leibniz's (by way of Wolff and Baumgarten). In other 144 Andrew Chignell 16 See his discussion of modality in the "Amphiboly" chapter of the first Critique, for example, especially A264/B320-A274/B330. words, the early Kant holds that merely by thinking through the concept of an object, we will be able to "see" whether its constituent predicates are logically consistent and really harmonious. For the pre-critical Kant, the fact that real possibilities are given to thought in this way – together with his rationalist commitment to grounding modal facts in something actual – constitutes the "only possible basis for a demonstration" of the existence of the most real being (ens realissimum) (2, pp. 77–86).17 In the critical period, Kant becomes more concerned about epistemological issues, and is no longer willing to grant that real possibility is simply given to us in conception. Instead, he seeks to establish how we can know that something is really possible in the first place – i.e. how we can justifiably claim that the positive predicates ("realities") composing its concept are really harmonious and not just logically consistent. With respect to the idea of an ens realissimum, for instance, Kant says in a lecture that we first "must be able to know that the effects of the realities do not cancel one another" before we can use it in an explanation (Lectures on Religion 28, pp. 1015–16). Such modal-epistemological questions can't be answered by appeal to some external ground; rather, we have to consider the nature and limits of our own intellectual faculties. Furthermore, an appeal to our consistent thought of a thing won't be enough, since mere thinking is said, in the critical period, to track logical rather than real possibility.18 The critical Kant thus adopts a broadly Lockean view of our epistemological access to relations of real repugnance and harmony in substances; he says we must identify a connection between the thing and experience if we want to be sure that our idea of it is not an empty "thought-thing." In a word: it is only possible for our reason to use the conditions of possible experience as conditions of the possibility of things (Sachen); but it is by no means possible for it as it were to create new ones independent of those conditions, for concepts of the latter sort, although free of contradiction, would nevertheless also be without any object (Gegenstand). (A771/B799) Note that although Kant's mature view is much closer to Locke's than to Leibniz's, it is nonetheless not completely Lockean. This passage and others show that, for Kant, we can justifiably take a combination of qualities to be really possible only by appealing to some actual or possible experience. By "possible experience" in this context, Kant means experience that someone with suitably enhanced perceptual faculties – or unrestricted traveling abilities – would have of this world without breaking the natural laws. Thus in effect the realm of knowable real possibility is broadened by Kant to include what is sensibly experienced and what can be connected by known laws to what is sensibly experienced. Kant calls this the realm of "empirical real possibility" in the PostuA Lockean Problem in Kant and Hegel 145 17 For detailed discussion of this argument, see Chignell, 2009. 18 See e.g. Bxxvi; Practical, 5, p. 136; "Orientation," 8, p. 137. lates chapter of the first Critique, and says that it is co-extensive with the realm of knowable actuality and knowable (causal) necessity (A232/B285). The main point for present purposes is that Kant thinks it is not epistemically rational to assent on theoretical grounds to propositions – even propositions that fall out of otherwise good arguments – without being able to "demonstrate" or "prove" that the objects of all the concepts they refer to are really possible (5, p. 398; A602/B630). As he says in the B-preface, "to cognize an object, it is required that I be able to prove its possibility (whether by the testimony of experience from its actuality or a priori through reason)" (Bxxvi). Kant is talking about real possibility here, as the passage goes on to clarify. The claim is that in order to count as theoretically cognizing an object (having theoretical knowledge about it), I must be able to provide full-blown proof (and not just probabilistic opinion or hypothesis) that it is really possible. So, even if I have a valid argument with apparently plausible premises, the conclusion can't count as cognition or knowledge unless I am able to prove that there is no real repugnance amongst the predicates of the concepts involved. The Kantian appropriation of the Lockean constraint can be captured in the following necessary condition on synthetic knowledge: Modal Condition: Necessarily, S knows that p only if S is in a position to prove the real possibility of the objects referred to in p. B.2 Positive Applications of the Modal Condition With respect to what Kant calls "empirically certain" knowledge of objects, the Modal Condition is satisfied by way of the subject's ability to appeal to her experiences or to the experiences of others. These are the same experiences that allow the relevant assent to satisfy other conditions for epistemic justification.19 In other words, the subject has perceptual "proof" that these objects actually exist, and then the proof of real possibility comes along for free, so to speak, by way of trivial inference from actuality to possibility (cf. Lectures on Metaphysics L2 28, p. 557). Something similar can be said of our "intuitively certain" synthetic a priori knowledge in mathematics. The mathematician must be in a position to appeal to a constructed example of the relevant objects in pure intuition in order to ground her assent about those objects, and so the Modal Condition is ipso facto satisfied just in case the other conditions on justification are satisfied. The case of synthetic a priori philosophical knowledge is more complex. The only assents that are epistemically justified in this context, according to Kant, 146 Andrew Chignell 19 For Kant's very general notion of "assent" (Fürwahrhalten), its various modes (including both belief and knowledge), and their justifications, see Chignell, 2007a. are based on "transcendental" arguments – "inference-to-only-possible-explanation" (IOPE) arguments from some known fact to the "only possible basis" of that fact.20 Consider, for instance, the following crude simplification of the argument of the Second Analogy: (1) Necessarily, we have cognitive experience only if every phenomenal event has a phenomenal cause. (2) We have cognitive experience. Thus, (3) Necessarily, every phenomenal event has a phenomenal cause. (1) says that the truth of the causal principle in (3) is part of the only possible explanation of a fact we take for granted – namely, (2). But given the Modal Condition, knowing that (1) or (3) requires that we be in a position to prove the real possibility of all the objects they refer to, and thus in a position to prove that (0) A phenomenal cause is really possible. Because "cause" is an a priori category, the truth of (0) must be proved by appeal to the sort of a priori content that Kant typically calls a "schema." A schema of a concept is (something like) a rule for how an object of that concept could be given in experience. Thus our being in a position to appeal to schemata is what allows synthetic principles generated from the categories to meet the Modal Condition and count as a priori knowledge for us. Conversely, the unavailability of schemata for "ideas" prevents them from figuring into items of knowledge: To demonstrate the reality of our concepts, intuitions are always required. If they are empirical concepts, then the latter are called examples. If they are pure concepts of the understanding, then the latter are called schemata. But if one demands that the objective reality of the concepts of reason, i.e., of the ideas, be demonstrated, and moreover for the sake of theoretical cognition of them, then one desires something impossible, since no intuition adequate to them can be given at all. (Judgment 5, p. 351) A Lockean Problem in Kant and Hegel 147 20 With respect to the pure concepts of the understanding, Kant says that "their objective reality is founded solely on the fact that because they constitute the intellectual form of all experience, it must always be possible to show their application in experience" (A310/B367). This is of course what Kant spends much of the Transcendental Analytic trying to establish. Conversely in the third Critique he says that the idea of a teleological causality in nature "can of course be thought without contradiction, but it is not good for any dogmatic [i.e. epistemic] designations, because, since it cannot be drawn from experience and is not required for the possibility of experience, its objective reality cannot be required by anything" (Judgment, 5, p. 397). So, there is no theoretical IOPE argument for the objective reality of this idea (and thus for the real possibility of natural teleology). In short: in transcendental IOPE arguments like (0)-(3), the real possibility of the object referred to in the conclusion once again comes along for free, as part of the basis for the conclusion itself. Without at least implicitly containing a premise like (0), however, the argument would be valid but rendered epistemically impotent by the Modal Condition, and thus result in rational belief at best. Probabilistic empirical knowledge in the natural sciences works quite differently (again recall here that Kant typically thinks of direct perceptual knowledge as well as some testimony-based knowledge as "empirically certain" and not probabilistic (cf. "Jäsche" 8, p. 70, or Real Progress 20, p. 299)). Consider the following inference-to-best-explanation (IBE) argument, where p is the proposition that the universe contains phlogiston: (1) We have observed phenomena X. (2) The best explanation of X, given our current knowledge of the causal laws and our best empirical theories, is that p. Thus, (3) Probably, p. This is again a crude simplification of a complex inference. The important point for our purposes is that the IBE referred to in (2) is not sufficient to license empirical certainty that p, and so even if p is true, our knowledge of it is probabilistic, as stated in (3). That means that our grounds for holding that p do not all by themselves provide full-blown "proof" of the real possibility of phlogiston in the way that, say, an observation or deductive proof of the existence of phlogiston would. In other words, proof of real possibility does not come along for free in the case of IBE. But can't we still know a proposition like p on the basis of such arguments? As we have seen, Locke's stern answer to the question would be No, if by "know" we are talking about the high-level knowledge (scientia) of the sort that he valorizes in the Essay. Our assent to p will at best be able to count as "right judgment," or "Belief," or "hypothesis," precisely because we cannot prove through mere conceiving or IBE reasoning that the quality-combinations referred to in our complex idea of phlogiston are really possible (again, cf. E 4.14). Kant departs from Locke in allowing propositions like (3) to count as knowledge, but his arguments on that score constitute (I submit) a weak point in his position. When discussing theoretical assents that are not "certain" because they are not based on direct observation or demonstrative inference, Kant suddenly starts appealing to a broader conception of real possibility – one that he calls "formal possibility" in one place (A127), though here I will call it "formal real possibility" in order clearly to distinguish it from merely "formal" or logi148 Andrew Chignell cal possibility.21 If we are in a position to know that the objects referred to in some proposition are appearances – i.e. objects located in the spatio-temporalcausal nexus governed by the "forms" of intuition and the general principles of pure understanding – then, says Kant, we are in a position to know that the truth of the proposition is compatible with the formal conditions of our experience. Being in such a position, moreover, is now said to be sufficient all by itself to allow assent to such a proposition to satisfy the Modal Condition and count, if true and otherwise justified, as knowledge. More generally: for Kant the conclusions of IBEs and other probabilistic inferences do satisfy the Modal Condition, as long as they refer exclusively to spatio-temporal appearances that we can prove to be formally really possible. The reason this seems like a weak point in Kant's position is because it is simply unclear how conceiving of something as part of the spatio-temporal nexus proves that it is not afflicted by subject-canceling real repugnance. Consider in this connection some of the usual examples from contemporary metaphysics: a donkey that is an orange, me with different parents than I actually have, water that isn't H2O, a zombie. Insofar as we successfully conceive of these things at all, we conceive of them as being in space and time and governed by the very general principles of pure understanding (cause-effect, substanceproperty, reciprocity, etc.). So they count as formally really possible on Kant's view, and thus propositions referring to them do satisfy the Modal Condition according to him. But surely there is still a serious question about whether such things are really possible! Without some independent account of why anything that is governed by the axioms and the principles cannot suffer from subjectcanceling real repugnance, then, Kant's appeal to "formal real possibility" as a way of satisfying the Modal Condition seems rather ad hoc. By contrast, the much stricter notion of "empirical real possibility" – i.e., conformity to space-time axioms, the principles of pure understanding, and the fine-grained empirical laws and facts about initial conditions – is such that by satisfying its conditions a thing is guaranteed to be exempt from real repugnance. That's because, as we have seen, something that is empirically really possible is in principle perceptible in this world and is thus actual. If we are in a position to know that all the objects referred to in p are empirically really possible, then we have obviously satisfied the Modal Condition. My suggestion, then, is that Locke took the more consistent – albeit more restrictive – position on this score. If knowledge requires the ability to prove real possibility, and if subject-canceling real repugnance is not ipso facto ruled A Lockean Problem in Kant and Hegel 149 21 Cf. A225/B272: "[W]ithout anticipating experience itself we can cognize and characterize the possibility of things solely in relation to the formal conditions under which something can be determined as an object in experience at all, thus fully a priori but only in relation to these conditions and within their boundaries." For an account of the various types of modality in Kant, see Chignell/Stang, 2010. out by spatio-temporal-categorial conformity (and again, it is very hard to see why it should be), then scientific theories that postulate quality-combinations that are not provably empirically really possible at most can deliver "right judgment" or "rational hypothesis," just as Locke said. Of course, this result may lead epistemologists with less exalted standards for knowledge than Locke or Kant to conclude that the Modal Condition itself has got to go. B.3. Negative Applications of the Modal Condition When he turns to cases of the supersensible – the realm beyond all possible empirical awareness – Kant joins Locke in holding that the Modal Condition prevents otherwise rational assents from counting as knowledge. Consider by way of (somewhat anachronistic) illustration the following argument against physicalism: (1) If physicalism is true, then it is necessary that physical properties of suchand-such a configuration are accompanied by consciousness. (2) It is really possible that there is a zombie, i.e. a being with physical properties of such-and-such a configuration but without consciousness. Thus, (3) Physicalism is not true. The argument is valid and (1) is merely a statement of the physicalist's position in the form of a conditional (where "such-and-such" is a placeholder for some complicated physical description). (2) explicitly asserts the real possibility of zombies. So even though this argument appeals to a strange metaphysical entity – the relevant qualities of which (let's grant) are imperceptible by us – the satisfaction of the Modal Condition will come along for free if premise (2) can be proved. The problem, of course, is that it is not clear where we could find independent proof of (2) if mere conceiving tracks the contours of logical rather than real possibility. In the absence of such, the argument will not be sound. Reflection on this case shows why Kant would not be a friend of the kind of "conceivability" arguments that are prominent in contemporary metaphysics. There is another kind of case involving the supersensible that requires examination, one that does not explicitly premise a claim about real possibility: (1) If I am causally responsible for some of my actions, then my will is incompatibilistically free. (2) I am causally responsible for some of my actions. Thus, (3) My will is incompatibilistically free. 150 Andrew Chignell Grant for the sake of argument that we prove (2) theoretically somehow.22 Can we appeal to (1) to ground knowledge of (3)? Kant's answer is No, and his reason is that (1) contains the idea of supersensible freedom. Although there is some positive content in the (let's suppose) logically consistent concept of a free will, we still lack theoretical proof that (0) An incompatibilistically free will is really possible.23 Thus, (1) is not a candidate for (theoretical) knowledge, and neither is (3). This is also the critical Kant's problem with his old speculative/theoretical proof from 1763. Throughout the critical period he thinks that the argument is still formally valid but he also holds that there is no way to ground the assumption that an ens realissimum is really possible. Thus the Modal Condition is no more satisfied with respect to the idea of God than it is with respect to the idea of freedom or the idea of a zombie: such ideas are of "mere thought-things (Gedankendinge), the possibility of which is not demonstrable, and which thus cannot be used to ground the explanation of actual appearances" (A771/B799). It is when we are dealing with ideas of deities, free wills, Twin Earths, souls, afterlives, zombies, worlds, and so forth, that the problem of real repugnance becomes a real problem.24 We have seen that the Modal Condition doesn't apply to belief/faith (Glaube): we do not have to be able to prove the real possibility of the objects involved in order for theoretical and practical beliefs about supersensibles to be rational.25 But while Locke seems happy to have scientific as well as speculative hypotheses count as "Belief" without further talk of proving real possibility, in the end Kant seems unwilling to relinquish the concerns underwriting the A Lockean Problem in Kant and Hegel 151 22 Kant himself advocated a theoretical proof of spontaneity in lectures well into the late 1770's (see 28, pp. 268 ff.) and perhaps even as late as the 1785 Groundwork (cf. 4, pp. 451–2). For discussion, see Ameriks, 2000a, pp. 189–233 and Pereboom, 2006. 23 By the time he wrote the second Critique, Kant explicitly holds that we don't have theoretical insight into "how freedom is even possible, and how one would theoretically and positively represent this kind of causality" (5, p. 133). 24 In discussing claims involving "ideas" in the Real Progress essay, Kant warns that we have to pay attention to "the modality of assent" (Modalität des Fürwahrhaltens), otherwise we will be led astray by an "alleged knowing and cognizing (vermeinten Erkennen und Wissen) in which we forget that these ideas have been arbitrarily (willkürlich) framed by ourselves, and are not derived from the objects, and thus entitle us to nothing more than an acceptance (Annehmen) in a theoretical sense, though they also allow us to maintain the rationality of such an acceptance from a practical point of view" (20, p. 300). Here we hear a distinct echo of Locke's warning, quoted earlier, that knowledge-claims "must not consist of Ideas put together at the pleasure of our Thoughts, without any real pattern they were taken from, though we can perceive no [logical] inconsistence in such a Combination" (E 4.4.12). 25 Note that Kant's notion of "belief" (Glaube) is not the same as the contemporary epistemologist's notion of "belief"; it is closer to Locke's notion of "Belief" and often translated as "faith." I use "belief" here but the differences should be kept in mind. Modal Condition altogether, even with respect to such non-epistemic attitudes. In other words, Kant seems convinced that some kind of response to the problem of real repugnance has to be offered if even mere belief (Glaube) is to be legitimate from a rational point of view. One motivation for this is presumably Kant's conviction – expressed in passages quoted earlier – that it isn't rational to assent to propositions that commit us to objects which may, for all we can tell, be really impossible. Another is that, for Kant, certain beliefs – especially moral and religious beliefs – are important and dearly held components of our picture of the world, and we do not want them to be vulnerable to charges of trafficking in speculative fancy. Ultimately, Kant offers three different responses or solutions to the problem of real repugnance vis-à-vis belief – responses that are not incompatible but seem to indicate an evolution of his views about the seriousness of the problem. I examine each of these in (Chignell 2010), and so here I simply provide a sketch. The first solution (prominent in the first Critique as well as the "Orientation" essay of 1786) appeals to the non-sensible "matter" or "content" provided by the needs and interests of reason that also justify the belief. Presumably what this means is that if we have "sufficient subjective grounds" for holding that an object is actual, then we also have sufficient subjective grounds (the same ones!) for holding that it is really possible. Here, just as in the cases of empirically certain knowledge and intuitively certain mathematical knowledge, the proof of real possibility (albeit a "subjective" proof in this case) comes along for free. The second solution (prominent in the second Critique and other ethical writings) appeals to a kind of non-sensible "practical cognition" that provides the basis for belief or even "practical knowledge" about specific supersensibles. Practical cognition and knowledge are different from their theoretical counterparts in complicated ways that cannot be discussed here; the important point, however, is that the second solution – like the first – appeals to the principle that actuality entails possibility. If we practically know that a thing is actual, then we practically know that it is really possible: a solution to the problem of real repugnance comes along for free, albeit in the practical rather than the theoretical mode. The third solution (prominent in the late 1780's in Real Progress, the third Critique, and beyond) continues this trend of seeking a stronger link between sensibility and belief by invoking the notion of "symbolism" or "schematism by analogy." Even if we can't exhibit or schematize an idea of the supersensible, Kant thinks we may be able to symbolize it by analogical appeal to sensible items, in order to gain a fragmentary grasp of what it would be like for it to have an actual object. The process of symbolization thus gives us a sensible albeit weak indication – a "trace or sign," as Kant says in a famous passage from the third Critique (5, p. 300) – of what the positive content of the idea is like, and of whether that content is really harmonious or really repugnant. 152 Andrew Chignell C. The Problem Dissolved by Hegel Kant was still alive, though no longer philosophically active, when Hegel published Belief and Knowledge (Glauben und Wissen) in the second volume of the Critical Journal of Philosophy in 1802. In the introduction to that work, Hegel cites the philosophy of Locke as one of the earliest manifestations of the "realism of finitude" that he aims to combat – i.e., the program that "raised the standpoint of the subject, the standpoint of absolutely existing finitude, to the first and highest place" (Hegel 1970, 4, p. 322). Hegel follows Kant in criticizing Locke for being too empirico-psychological in his method and for thus failing to recognize the epistemic role of the transcendental forms and categories of cognition. He then charges both Locke and Kant with treating "Reason" as "solely immersed in finitude, a Reason that renounces intuition and cognition of the eternal." The philosophies of Kant, Jacobi, and Fichte are the completion and idealization of [Locke's] empirical psychology; they consist in coming to understand that the infinite concept is strictly opposed to the empirical[...]. They understood the eternal to be above this opposition, beyond the concept and the empirical; but they understood the cognitive faculty and Reason simply to be this sphere [of opposition]. Now a Reason that thinks only the finite will of course be found to be able to think only the finite [...]. (1970, 4, p. 322) Hegel says here that a mistake common to Locke and Kant is that of taking the finite empirical world together with the "infinite" domain of mathematical, abstract, and practical rationality to constitute the entire sphere of human knowledge, and of setting the concrete supersensible over and against this as the sphere of mere belief: "Once it gets clear about its restriction to the sensuous [...] philosophy is supposed to prettify itself with the surface color of the supersensible by pointing, in belief, to something higher" (1970, 4, p. 323). Obviously the young Hegel thinks such a constraint on knowledge is misguided; what he and his collaborator Schelling aim to show is that the mind is capable of going beyond the finite/infinite opposition and of apprehending the concrete "eternal" through a kind of intellectual intuition (Schelling) or rational speculation (Hegel). In his later works, Hegel continues to criticize his predecessors for denying the possibility of speculative knowledge, but by this time he seems to realize that part of his criticism has to be directed at their modal metaphysics and epistemology. In a Zusatz to the Encyclopedia Logic, Hegel says that "the notion of possibility appears initially to be the richer and more comprehensive determination, and actuality, in contrast, as the poorer and restricted one." But in fact "actuality is the more comprehensive, because, being the concrete thought, it contains possibility within itself as an abstract moment." To regard something as merely possible, he says, is to think of it "in the form of abstract identity" – i.e., in a form such as 'S is p.' But this is an "abstract" form into A Lockean Problem in Kant and Hegel 153 which virtually any content can be thought: Hegel's examples are that of a Sultan becoming the bishop of Rome, and the moon crashing into the earth. "Thinkability" of this sort has no built-in constraints, and so if we separate a thing in thought from all the "relations in which it stands, even the most absurd and nonsensical suppositions can be considered possible" (Hegel 1991, EL § 143 Zusatz, p. 216).26 Hegel's examples here involve causal possibilities, but he holds something similar about real possibility as well: only the "uneducated" and "pub politicians in the political domain" are content to traffic in such "empty possibilities," abstracted as they are from the complete "determinations, circumstances, and conditions" required for inclusion in the concrete absolute (Hegel, 1991, EL § 143, Zusatz, p. 216; Hegel, 1969, p. 547). The "educated" person, by contrast, recognizes that there is no way to tell through mere conceiving whether an object is possible or impossible, and thus that the only useful concept of "real possibility" includes all antecedent conditions and is thus co-extensive with the actual (Hegel, 1991, EL § 147, p. 220). Hegel's opposition to the viability of any abstract notion of possibility comes out even more clearly when he argues (in the Science of Logic as well as the Encyclopedia Logic) that just as everything can be considered possible in abstract thought, "everything can be considered impossible, since any content (which, as such, is always something-concrete) contains not only diverse but also opposite determinations" (Hegel, 1991, EL § 143, Zusatz, p. 217).27 To establish this, Hegel cites, first, "the I" which is "at once simple self-relation as well as, unconditionally, relation to another" and, second, "matter [...] because it is the unity of repulsion and attraction." He also mentions "life," "law," "freedom," and "the Trinity" in this connection, though without any serious discussion (ibid.). Whatever we think of these examples, a natural way to interpret Hegel's main point here is as a holist one: conceiving an object apart from its relations to other objects leads to the loss of any clear sense of whether or not it is really possible. True, if we focus on some putatively "internal" subset of an individual's properties, it may seem to us to be possible. But if we focus on another subset it may just as well seem impossible. In fact, Hegel suggests, most or even all of our concepts contain prima facie incompatibilities that may lead us to think, in the absence of argument or experience to the contrary, that their objects are impossible. As a result, he issues a stern "warning not to use this category [of possibility] which has already been shown up as untrue even on its own account" (1991, EL § 143, p. 216). There is simply no non-arbitrary way of 154 Andrew Chignell 26 See Hegel, 1969, p. 542: To say that something is formally (i.e., logically) possible is "equally to say nothing." 27 "Therefore everything is just as much something contradictory and therefore impossible" (Hegel, 1969, p. 543). privileging a subset of a thing's properties as internal or essential and then evaluating the consistency and compatibility of just those properties in order to determine what the Leibnizeans called its "per se" modal status.28 Hegel appears to be taking direct aim at his predecessors' modal epistemology when he concludes, as a result of all this, that "there should be no talk in philosophy of proving that something is possible, or that something else is possible too; and that something, as people also say, is 'thinkable'" (ibid.). If we cannot determine what is really possible without considering the whole and all the relations between the individuals within that whole, then logical possibility – as well as Kant's formal real possibility and absolute real possibility – are empty and useless abstractions that philosophy must abjure: It is the empty understanding that roams around in these empty forms, and the business of philosophy with regard to them consists simply in exhibiting their nullity and lack of content. Whether this or that is possible or impossible depends on the content, that is, on the totality of the moments of actuality, and actuality which, in the unfolding of its moments, proves to be Necessity. (1991, EL § 143, Zusatz, p. 217, my emphasis) Now as we have seen, Kant is aware in the Postulates that if we include the "totality" of the determinations, circumstances, and conditions that Hegel mentions, then we end up with a domain of possibility that is co-extensive with the domain of actuality and necessity (recall that Kant calls this "empirical real possibility"). But Kant also believes that (a) we are able to abstract from all "real" conditions and tell whether something is a logical possibility, (b) we are able to abstract from specific empirical and causal conditions and tell whether something is a "formal real possibility," and (c) we are able to abstract from all empirical, causal, and spatio-temporal-categorial conditions in general and think (though not know) of something as an "absolute real possibility." Hegel insists, over and against Kant, that all talk of mere possibility is just empty abstraction and of no philosophical use – not even a negative one. Is there any way to adjudicate this dispute? The first thing to do, I submit, is to bracket Hegel's radical-sounding claim that any abstraction from the fine-grained conditions on actual existence somehow results in an absurd theoretical situation where everything is both possible and impossible. (Before bracketing it, however, let me just mention that it is hard to see how logical impossibilities – married bachelors, cows that are not cows, etc. – would start to seem possible if we considered them apart from the various causal and metaphysical conditions on their existence. Perhaps Hegel is suggesting, less radically, that we simply don't know how to separate the logical A Lockean Problem in Kant and Hegel 155 28 This is obviously a somewhat deflationary reading of Hegel's claim that all concepts (and their objects) contain oppositions within themselves. More robust readings are possible, though not perhaps as charitable. constraints from the extra-logical ones in a principled fashion. Or perhaps Hegel has misunderstood Kant's doctrine of pure "thought" – the doctrine according to which a priori thoughts and ideas are still governed by logical constraints like consistency and can be usefully analyzed and employed by the understanding, though not for the purposes of knowledge.)29 The really interesting issue for present purposes has to do with Hegel's skepticism about the two intermediary domains between logical possibility and empirical real possibility – namely, formal real possibility and absolute real possibility. As noted earlier, Hegel's criticism is directed against philosophers who start with the standpoint of "finite subjectivity" and then take our inability to know what is really possible to underwrite a constraint on theoretical and speculative knowledge. One way to articulate his own skepticism, as we have seen, is as not epistemological but rather metaphysical: i.e., not about our epistemic ability to track real possibility but rather about the stability and coherence of the very notion. Again, for Hegel there is no principled, ultimate distinction between inner and outer: synchronic and diachronic relations between individual objects, and between them and the absolute whole, are as "essential" to these objects' being what they are as any putatively internal or intrinsic properties. Thus, if we know that something satisfies all the conditions for being really possible, then we know that it is also actual: "When all the conditions of something are completely present, it enters into actuality" (1969, p. 548).30 But if this account of the dispute between Kant and Hegel is correct, then it is a very deep one – irresolvable here, certainly – since it appears to be motivated for Hegel by a thoroughgoing (dialectical) holism. That said, there are many non-holist contemporary philosophers who also doubt not just our ability to know about real modality but also the very coherence of the notion, and who suggest that our talk of possibility and necessity can be captured adequately by logical or causal notions, or some combination thereof.31 Of course, knockdown arguments in this arena are notoriously rare: the foe of metaphysical modality is unlikely to be able to show, with respect to all the classic examples that are usually cited in this context, that such a reduction is in principle possible. And the defender of metaphysical modality is unlikely to come up with a case of real repugnance that everyone will recognize as irreducible to some complex of logical or causal oppositions. 156 Andrew Chignell 29 See Ameriks, 2000b, pp. 294 ff. for an account of Hegel's apparent misunderstanding of Kant here. 30 See Hegel, 1991, EL § 147, p. 220: "When all conditions are present, the thing (Sache) must become actual." 31 See the essays in Gendler and Hawthorne, 2002, especially the editors' introduction. In any case, our inquiries here reveal that Hegel doesn't so much solve the problem of real repugnance as dissolve it: he holds that we must either be able to show that something is part of the actual, all-encompassing absolute, or refrain from using it in strict philosophical explanations altogether. Interestingly, this turns out to be closer to Locke's position than it is to Kant's: Locke too, recall, thinks that we need independent proof that a quality-combination is actual in order to use it in constructing ideas of possible substances, whereas Kant allows proof of real possibility to be distinct from proof of actuality in some circumstances. Hegel goes further than Locke, however, by claiming that strictlyspeaking there is no appropriate use of an abstract notion of "possibility," even if the complex idea of some possible being is constructed from simple ideas whose real harmony we've already proved. Strictly-speaking the only appropriate notion of real possibility is coextensive with the notion of the actual (and the necessary). Thus the problem of real repugnance is replaced with a straightforward problem of actuality.32 D. Conclusion One of Kant's main concerns with respect to "transcendental ideas" stems from the fact that they may refer, for all we know, to really rather than logically impossible things. This concern about real repugnance leads to the development of the Modal Condition that, in turn, helps to underwrite Kant's famous prohibition on positive knowledge of particular things-in-themselves. I have argued here that a version of this concern can be found in Locke and that it led him to place significant constraints on theoretical claims about substances and their qualities. With respect to "Belief," Locke is more permissive and apparently unconcerned to rule out real repugnancies between the qualities we postulate in things. Kant, by contrast, worries as well about whether the objects of belief (Glaube) are really possible, and develops three different solutions to this version of the problem. Hegel was familiar with this distinction between logical and real possibility and also very likely with the problem for speculation that his predecessors saw A Lockean Problem in Kant and Hegel 157 32 A famous contemporary holist once warned that a regrettable "reversion to Aristotelian essentialism is required if quantification into modal contexts is to be insisted on. An object, of itself and by whatever name or none, must be seen as having some of its traits necessarily and other contingently [...]" on such a view. But this kind of "favoritism among the traits of an object," says Quine, is unjustified: "the latter [contingent] traits follow just as analytically from some ways of specifying the object as the former [necessary] traits do from other ways of specifying it" (Quine 1961, pp. 154–55). For provocative reflections on the suggestion that "Quine was the Hegel of contemporary philosophy," see Franks, 2007. in our inability to track the latter through mere conceiving. In response, he argues that all "proofs of possibility" are fruitless and nonsensical unless they also count as proofs of actuality. By denying the claim – found in empiricists, rationalists, and critical philosophers alike – that there is a principled distinction between the "internal" possibility of a thing and its "external" all-things-considered possibility, Hegel effectively collapses the problem of how to know what is really possible into the problem of how to know what is both actual and necessary.33 References Adams, Robert M. (1997): "Things in themselves," Philosophy and Phenomenological Research 57, 4, pp. 801–825. Adickes, Erich (1924): Kant und das Ding an sich, Berlin. Ameriks, Karl (1992): "The Critique of Metaphysics: Kant and Traditional Ontology," in: Guyer, Paul (ed.): Cambridge Companion to Kant, New York, pp. 249–279. –, (2000a): Kant's Theory of Mind, second ed., Oxford. –, (2000b): Kant and the Fate of Autonomy, New York. Chignell, Andrew (2007a): "Kant's Concepts of Justification," in: Nous 41, 1, pp. 33–63. –, (2007b): "Belief in Kant," in: Philosophical Review 116, 3, pp. 323–360. –, (2009): "Kant, Modality, and the Most Real Being," in: Archiv für Geschichte der Philosophie 91, 2, pp. 157–192. –, (2010): "Real Repugnance and Belief about Things-in-Themselves: A Problem and Kant's Three Solutions" in: Krueger James/Lipscomb Ben (eds.): Kant's Moral Metaphysics, Berlin. Chignell, Andrew/Stang, Nicholas (2011): "Postulate des empirischen Denkens," in: Mohr, Georg/Stolzenberg, Jürgen/Willaschek, Marcus (eds.): Kant-Lexikon, Berlin. Downing, Lisa (2008): "The 'Sensible Object' and the 'Uncertain Philosophical Cause,'" in: Garber Daniel/Longuenesse, Béatrice. (eds.): Kant and the Early Moderns, Princeton, pp. 100–116. Franks, Paul (2007): "From Quine to Hegel," in: Hammer, Espen (ed.): German Idealism: Contemporary Perspectives, New York, pp. 50–69. Gendler, Tamar Szabo/Hawthorne, John (eds.) (2002): Conceivability and Possibility, New York. Grier, Michelle (2001): Kant and the Doctrine of Transcendental Illusion, New York. Guyer, Paul (1987): Kant and the Claims of Knowledge, New York. 158 Andrew Chignell 33 I am grateful to Anja Jauernig and Desmond Hogan for numerous conversations about real possibility over the years, and to Nicholas Sturgeon for emphasizing the importance of Locke in this connection. My thanks are also due to Patrick Kain, Avishai Margalit, Colin McLear, Lawrence Bruce-Robertson, and the editors of this journal for feedback on earlier drafts, and to Karl Ameriks, Richard Boyd, Derk Pereboom, Nicholas Stang, Eric Watkins, and Morton White for helpful discussion. –, (2008): "Kant's Transcendental Idealism and the Limits of Knowledge: Kant's alternative to Locke's physiology" in: Garber, Daniel/Longuenesse, Béatrice (eds.): Kant and the Early Moderns, Princeton, pp. 79–99. Hegel, G. W. F. (1969): Science of Logic (Wissenschaft der Logik), trans. Miller, A.V., New York. –, (1970): Glauben und Wissen in: Werke vol 4, Moldenhauer E./Michel, K. M. (eds.). Frankfurt/M. –, (1991): The Encyclopaedia Logic: Part I of the Encyclopaedia of Philosophical Sciences with the Zusätze, trans. T. Geraets, W. Suchting and H. Harris, Indianapolis. Hogan, Desmond (2009): "How to know Unknowable Things in themselves," in: Nous 43, 1, pp. 49–63. Kant, Immanuel (1902): Kants gesammelte Schriften, Königlich Preussischen Akademie der Wissenschaften (ed.), Berlin. [Critique of Pure Reason is cited by the A-edition (1781)/B-edition (1787) pagination. All other works are cited as follows: "abbreviated name, volume, page"] Langton, Rae (1998): Kantian Humility: Our Ignorance of Things in Themselves, New York. Leibniz, G.W. (1875–90): Die philosophischen Schriften von Gottfried Wilhelm Leibniz, ed. C. I. Gerhardt, Berlin. –, (1948): Textes Inédites, 2 vols., ed. G. Grua, Paris. Locke, John (1823): The Works of John Locke, 10 volumes, London. –, (1975): Essay concerning Human Understanding, Oxford. [Cited by book, chapter, and section numbers.] Newman, Lex (2004): "Locke on Sensitive Knowledge and the Veil of Perception – Four Misconceptions," in: Pacific Philosophical Quarterly 85, pp. 273–300. Pereboom, Derk (2006): "Kant on Transcendental Freedom," in: Philosophy and Phenomenological Research 73, 3, pp. 537–567. Prauss, Gerold (1974): Kant und das Problem der Dinge an sich, Bonn. Quine, W. V. O. (1961): From a Logical Point of View, revised 2nd edition, New York. Watkins, Eric (2009): "Kant on the Hiddenness of God," in: Kantian Review 14, 1, pp. 81–122. Wilson, Margaret (1999): "Superadded Properties," in: Wilson, Margaret, Ideas and Mechanism: Essays on Early Modern Philosophy, Princeton, pp. 196–208. A Lockean Problem in Kant and Hegel