Reinier Munk (ed.), Moses Mendelssohn's Metaphysics and Aesthetics, Studies in German Idealism 13, DOI 10.1007/978-94-007-2451-8_8, © Springer Science+Business Media B.V. 2011 It is well known that, from late 1770 onwards, Mendelssohn suffered from a nervous debility that prevented him from engaging with the speculative subtleties of the most recent philosophical systems. Among the fi rst reports of this complaint is in a letter containing a reply to Kant's Inaugural Dissertation 1 where Mendelssohn writes that "my nervous infi rmities make it impossible for me of late to give as much effort of thought to a speculative work of this stature as it deserves." 2 Later, and more famously, Mendelssohn would claim in the Preface to Morgenstunden that, C. W. Dyck (*) Department of Philosophy, University of Western Ontario , London , Canada e-mail: cdyck5@uwo.ca Chapter 8 Turning the Game Against the Idealist: Mendelssohn's Refutation of Idealism in the Morgenstunden and Kant's Replies Corey W. Dyck 1 All references to Mendelssohn's works are to the Gesammelte Schriften. Jubiläumsausgabe (Berlin: Akademie-Verlag, 1929–; Stuttgart/Bad Cannstatt: Frommann-Holzboog, 1971–). Hereafter cited as JubA and volume number, followed by a colon and page number. Translations from the essay "On Evidence in the Metaphysical Sciences" are taken from Philosophical Writings , ed. and trans. Daniel O. Dahlstrom (Cambridge: Cambridge University Press, 1997); and those from Morgenstunden are taken from Morning Hours: Lectures on God's Existence , trans. Daniel O. Dahlstrom and Corey Dyck (Dordrecht: Springer, 2011). Translations from Kant's Kritik der reinen Vernunft [ KrV ] are taken from the Critique of Pure Reason , ed. and trans. P. Guyer and A. Wood (Cambridge: Cambridge University Press, 1998). Translations of other citations from Kant's works, published or otherwise, are taken from the Cambridge edition of Kant's works, including Theoretical Philosophy 1755–1770 (for the Inaugural Dissertation ), ed. and trans. D. Walford and R. Meerbote (Cambridge: Cambridge University Press, 2003) and Correspondence , ed. and trans. A. Zweig (Cambridge: Cambridge University Press, 1999). All other translations of Kant are my own. Citations from the KrV refer to the pagination in the fi rst "A" edition and, where appropriate, to the second, "B" edition. All other citations to Kant's works refer to the volume and page number in the so-called "Akademie Ausgabe" of his Gesammelte Schriften (Berlin: Georg Reimer, 1900–; Berlin/Leipzig: De Gruyter, 1968–, cited as AA . 2 AA 10:113: "ob ich gleich seit Jahr und Tag, wegen meines sehr geschwächten Nervensystems, kaum im Stande bin, etwas spekulatives von diesem Werthe, mit gehöriger Anstrengung durch zu denken." 160 C.W. Dyck due to his ailment, he has had to content himself with only second-hand accounts of the works of various authors: as he puts it, "I am acquainted with the writings of great men who have distinguished themselves in metaphysics during [the past 12–15 years], the works of Lambert, Tetens, Plattner and even the all-quashing Kant, only from insuffi cient reports of my friends and from learned reviews that are rarely more instructive." 3 While the effects of this debility can hardly be doubted, 4 there are some indications that in spite of it Mendelssohn had attempted to come to grips with the metaphysical texts of his most illustrious contemporaries, and with Kant's in particular. So, in a letter he wrote to Kant in 1783, he claims that "your Critique of Pure Reason is also a criterion of health for me. Whenever I fl atter myself that my strength has increased I dare to take up this nerve-juice consuming book, and I am not entirely without hope that I shall still be able to think my way through it in this life." 5 Without recommending the use of one's grasp of the fi rst Critique as a criterion of good health (since that would imply that we are all ailing), Mendelssohn's letter makes clear that his familiarity with Kant's text was not entirely second-hand, and indeed that he made a serious, if not sustained, effort to understand it. In fact, there is good reason to think that Mendelssohn was rather familiar with some of the key claims of Kant's fi rst Critique ( KrV ) and that parts of Morgenstunden were intended as a direct attack on Kantianism, as Altmann and others have noted 6 ; as far as I can tell, however, this criticism has yet to be considered in the appropriate context or presented in all of its systematic detail. In what follows, I will show that far from being an isolated assault, Mendelssohn's attack in the Morgenstunden is a continuation and development of his earlier criticism of Kant's idealism as presented in the Inaugural Dissertation . In the fi rst section I will briefl y present Mendelssohn's initial criticism of Kant's doctrine of the subjectivity of time as elaborated in the Dissertation , along with Kant's (eventual) reply in the Transcendental Aesthetic of the KrV . In the second section I turn to the Morgenstunden where Mendelssohn begins by challenging Kant's distinction between transcendental and empirical idealism and then returns to his previous criticisms of Kant, developing 3 JubA 3.2:3: "Ich kenne daher die Schriften der grossen Männer, die sich unterdessen in der Methaphysik hervorgethan, die Werke Lamberts, Tetens, Platnners und selbst des alles zermalmenden Kants , nur aus unzulänglichen Berichten meiner Freunde oder aus gelehrten Anzeigen, die selten viel belehrender sind." 4 See, for instance, Alexander Altmann, Moses Mendelssohn: A Biographical Study (London: Routledge and Kegan Paul, 1973), 268. 5 AA 10:308: "Ihre Kritik der reinen Vernunft ist für mich auch ein Kriterium der Gesundheit. So oft ich mich schmeichele, an Kräften zugenommen zu haben, wage ich mich an dieses Nervensaftverzehrende Werk, und ich bin nicht ganz ohne Hoffnung, es in diesem Leben noch ganz durchdenken zu können." 6 See Benno Erdmann, Kant's Kriticismus in der ersten und in der zweiten Aufl age der "Kritik der reinen Vernunft": Eine historische Untersuchung (Hildesheim: Verlag Dr. H. A. Gerstenberg, 1973), 118–21; Altmann, Moses Mendelssohn , 677; Frederick C. Beiser, The Fate of Reason: German Philosophy from Kant to Fichte (Cambridge, MA: Harvard University Press, 1987), 105–7; and Francesco Tomasoni, "Kant and Mendelssohn: A Singular Alliance in the Name of Reason," History of European Ideas 30 (2004): 267–94, esp. 268, 289–90. 1618 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... them considerably in an ambitious attempt "to refute the project of the idealists" ( JubA 3.2:55; das Vorhaben der Idealisten zu widerlegen). Finally, in the third section, I show that Mendelssohn's objection was more infl uential on Kant than has previously been suspected; not only did Kant respond to it in a brief review and a set of remarks published along with a disciple's examination of Mendelssohn's text but, as I will suggest, Kant's Refutation of Idealism is intended (at least in part) to undermine the Cartesian starting-point Mendelssohn had presumed throughout his campaign against Kantian idealism. 1 Mendelssohn's Criticism of the "Dissertation" and Kant's Critical Reply Kant's treatise "On the form and principles of the sensible and intelligible world," or the Inaugural Dissertation , of 1770, introduces a number of key claims that will later fi gure in the Critical doctrine of sensibility, including the thesis that time (along with space) is a subjective form rather than something pertaining to things in themselves and that, consequently, all objects in time (and space) have a merely ideal existence. Kant argues for the subjectivity of time by showing that conceiving time as an object or as a determination of an object (whether an accident or relation) cannot account for the character of the representation of time that we have, namely, that it is a pure intuition. Given this, Kant contends that time must be subjective, that is, "the subjective condition which is necessary, in virtue of the nature of the human mind, for the co-ordinating of all sensible things in accordance with a fi xed law." 7 That time is subjective in this way implies that objects, insofar as they have a temporal form, cannot be ascribed an existence independent of the subject but are only "clothed with a certain aspect , in accordance with stable and innate laws" (secundum stabiles et innatas leges speciem quandam induant) that have their origin in the subject ( AA 2:393). Moreover, it is precisely because time has as its basis a stable law within the subject that putative cognitions of objects in it can be taken as "in the highest degree true" despite the fact that they "do not express the internal and absolute quality of objects" ( AA 2:397; neque internam et absolutam obiectorum qualitatem exprimant). Yet, as Kant makes clear, none of this is to deny that something exists independent of the subject and stands in certain relations which only appear to us as in time; rather, the form of the same representation is undoubtedly evidence of a certain reference or relation in what is sensed, though properly speaking it is not an outline or any kind of schema of the object, but only a certain law, which is inherent in the mind and by means of which it co-ordinates for itself that which is sensed from the presence of the object. 8 7 AA 2:400: "sed subiectiva condicio per naturam mentis humanae necessaria, quaelibet sensibilia certa lege sibi coordinandi." 8 AA 2:393: "ita etiam eiusdem repraesentationis forma testatur utique quendam sensorum respectum aut relationem, verum proprie non est adumbratio aut schema quoddam obiecti, sed nonnisi lex quaedam menti insita, sensa ab obiecti praesentia orta sibimet coordinandi." 162 C.W. Dyck Kant does not take his idealistic conclusions, then, to be incompatible with the claim that objects exist in a manner distinct from how they are represented by the subject. Indeed, in the Dissertation , Kant goes further than this and allows for the cognition of objects, and their relations, taken in this way through the (real) use of the understanding. In accordance with this use, concepts are employed that "are given by the very nature of the understanding" ( AA 2:394; dantur per ipsam naturam intellectus), rather than by way of sensibility. Kant sent his Dissertation to a number of philosophers, including J. H. Lambert, Johann Georg Sulzer, and Mendelssohn, each of whom replied with criticisms. Signifi cantly, in spite of philosophical differences among them, the respondents unanimously rejected Kant's argument for the subjectivity of time and each for similar reasons. Lambert, who was the fi rst to respond in a letter of October 13, 1770, puts the objection in the following way: The trouble seems to lie only in the fact that one must simply think time and duration and not define them. All changes are bound to time and are inconceivable without time. If changes are real, then time is real , whatever it may be. If time is unreal, then no change can be real . I think, though, that even an idealist must grant at least that changes really exist and occur in his representations, for example, their beginning and ending. Thus time cannot be regarded as something unreal . 9 Here, Lambert argues that the idealist, even of the Kantian stripe, must concede the reality of changes among a subject's own representations since, for all such representations, the subject can identify a determinate beginning and ending in time. Thus time, at least, must be admitted to be real in the case of the representing subject, whatever its status might be with regard to the objects that are represented as in time. Mendelssohn, in his response in a letter of December 25, 1770, levels the same essential objection but draws the key contrast more sharply: For several reasons I cannot convince myself that time is something merely subjective. Succession is to be sure at least a necessary condition of the representations of fi nite minds. But fi nite minds are not only subjects; they are also objects of representations, both those of God and those of their fellow minds. Consequently succession is to be regarded as something objective. 10 As Mendelssohn counters, we might convince ourselves that time is subjective if we limited our consideration to the perspective of the representing subject since, from 9 AA 10:107: "Es scheint nur daran zu ligen, dass man Zeit und Dauer nicht defi n iren sondern schlechthin nur denken muss. Alle Veränderungen sind an die Zeit gebunden und lassen sich ohne Zeit nicht gedenken. Sind die Veränderungen real so ist die Zeit real , was sie auch immer seyn mag. Ist die Zeit nicht real so ist auch keine Veränderung real . Es däucht mich aber doch, dass auch selbst ein Ideal iste wenigstens in seinen Vorstellungen Veränderungen, wie Anfangen und Aufhören derselben zugeben muss, das wirklich vorgeht und exist irt. Und damit kann die Zeit nicht als etwas nicht real es angesehen werden." 10 AA 10:115: "Dass die Zeit etwas blos Subjektives seyn sollte, kan ich mich aus mehrern Gründen nicht bereden. Die Succession ist doch wenigstens eine nothwendige Bedingung der Vorstellungen endlicher Geister. Nun sind die endlichen Geister nicht nur Subjekte, sondern auch Objekte der Vorstellungen, so wohl Gottes, als ihrer Mitgeister. Mithin ist die Folge auf einander, auch als etwas objektives anzusehen." 1638 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... that perspective, there is no basis for determining whether the temporal order of our representations is grounded in their objects or in ourselves. Nonetheless, the claim that time is subjective cannot be sustained when we consider the representing subject as itself an object of representation on the part of other minds. This is because, considered from the perspective of such minds, including God's, the representing subject does not merely represent objects successively but is also itself the subject of successive representations; thus, the representing subject must be recognized as itself changing with respect to these representations. Despite the obvious continuity between Lambert's and Mendelssohn's criticism, we might note a couple of differences in emphasis that will become important in what follows. First, Mendelssohn stresses that whatever uncertainty the subject might have regarding the reality of time as it applies to its own representations can be resolved through a comparison of one's own perspective with those of other fi nite minds and with the way in which objects (in this case, the representing subject) would be exhibited to God. This is to presume, of course, that there is suffi cient agreement between the ways in which the subject is exhibited to other minds, both fi nite and infi nite, to make such a comparison possible. This is not unambiguously the case with Lambert who, while he sees no reason to hold with Kant that time "is only a helpful device for human representations" ( AA 10:107; nur ein Hülfsmittel zum Behuf der menschlichen Vorstellungen sey), would nonetheless likely dismiss the question of how such things might be exhibited to God as "impervious to clarifi cation" ( AA 10:108; was nicht klar gemacht werden kann). Second, where Lambert is content to assert the reality of time in the alterations of the subject without taking further issue with those who "want to regard time and space as mere pictures and appearances" insofar as it applies to objects in the world ( AA 10:108), Mendelssohn takes the reality of time in the case of the subject of changing representations to support its reality with respect to the objects of those representations: as he writes, "since we have to grant the reality of succession in a representing creature and in its alterations, why not also in the sensible object, the model and prototype of representations in the world?" 11 Kant had no choice but to take seriously this uniform opposition to his claim that time is subjective. In the letter to Herz of February 12, 1772, he confesses that this objection "has made me refl ect considerably" ( AA 10:132) and he formulates an initial response though, because it is not clear whether this was ever communicated to Mendelssohn (or Lambert), I will not take it up here. 12 In any case, Kant evidently continued to refl ect on the objection, as he would return to it in the KrV in the 11 AA 10:115: "Da wir übrigens in den vorstellenden Wesen und ihren Veränderungen eine Folge zugeben müssen, warum nicht auch in dem sinnlichen Objekte, Muster und Vorbild der Vorstellungen, in der Welt?" 12 Indeed, it is highly unlikely that Herz, a physician, would have passed along Kant's criticism to Mendelssohn on account of the latter's nervous condition (cf. Herz's letter to Kant of July 9, 1771 [ AA 10:126–27]). For a thorough discussion of the fi rst response contained in Kant's letter to Herz, see Lorne Falkenstein, Kant's Intuitionism: A Commentary on the Transcendental Aesthetic (Toronto: University of Toronto Press, 2004), 338–45. 164 C.W. Dyck Elucidation that follows the discussion of time in the Transcendental Aesthetic. After presenting his summation of the argument, he responds to the insinuation that the subjectivity of time implies the unreality of the representing subject: There is no diffi culty in answering. I admit the entire argument. Time is certainly something real, namely the real form of inner intuition. It therefore has subjective reality in regard to inner experience, i.e., I really have the representation of time and of my determinations in it. It is therefore to be regarded really not as object but as the way of representing myself as object. 13 Where Kant had previously taken the reality of time and objects in it to consist in the fact that "something real corresponds to the appearance" (cf. AA 10:134), he now explicitly denies that his subjectivity thesis in any way implies the unreality of the object of inner experience considered merely as appearance. As Kant has claimed, time is empirically real inasmuch as it has "objective validity in regard to all objects that may ever be given to our senses" (A35/B52; objektive Gültigkeit in Ansehung aller Gegenstände, die jemals unsern Sinnen gegeben werden mögen); consequently, the subject that is represented as an object in time is as real as any object that is represented in accordance with the forms of sensibility. This response, relying as it does on common forms of human sensibility, might seem to take Kant in the direction of Mendelssohn's contention that the objectivity of time is ultimately founded in some broad agreement among fi nite (and infi nite) minds in their representations of the changes in a given subject. Yet Kant, invoking the transcendental ideality of time, denies that this follows: But if I or another being could intuit myself without this condition of sensibility, then these very determinations, which we now represent to ourselves as alterations, would yield us a cognition in which the representation of time and thus also of alteration would not occur at all. Its empirical reality therefore remains as a condition of all our experiences. Only absolute reality cannot be granted to it according to what has been adduced above. 14 Kant maintains that, for a being like God, who lacks a faculty of sensible intuition, or for a fi nite mind with a different form of sensible intuition, a fi nite thinking subject taken as an object will not be represented as changing in time; thus, there is no need to admit the transcendental reality of time with respect to the representing subject. Kant thus seeks to avoid the problem articulated by Lambert and Mendelssohn by applying the distinction between two ways in which an object 13 KrV , A37/B53-54: "Die Beantwortung hat keine Schwierigkeit. Ich gebe das ganze Argument zu. Die Zeit ist allerdings etwas Wirkliches, nämlich die wirkliche Form der innern Anschauung. Sie hat also subjective Realität in Ansehung der innern Erfahrung, d.i. ich habe wirklich die Vorstellung von der Zeit und meinen Bestimmungen in ihr. Sie ist also wirklich, nicht als Object, sondern als die Vorstellungsart meiner selbst als Objects anzusehen." 14 KrV , A37/B54: "Wenn aber ich selbst oder ein ander Wesen mich ohne diese Bedingung der Sinnlichkeit anschauen könnte, so würden eben dieselben Bestimmungen, die wir uns jetzt als Veränderungen vorstellen, eine Erkenntniss geben, in welcher die Vorstellung der Zeit, mithin auch der Veränderung gar nicht vorkäme. Es bleibt also ihre empirische Realität als Bedingung aller unsrer Erfahrungen. Nur die absolute Realität kann ihr nach dem oben Angeführten nicht zugestanden werden." 1658 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... might be considered, either as it is in itself or as an appearance, not only to the objects of our representations but to the subject and its representations as well. Once this is admitted then, according to Kant, there is no diffi culty in upholding the (empirical) reality of the subject and its representations considered as appearances in time, but denying that time pertains to the subject and its representations considered as they are in themselves. 15 2 Mendelssohn's Refutation of the Idealist in Morgenstunden Even if his ill-health did not permit him to work his way through the entire KrV , Mendelssohn's attention would certainly have been drawn to Kant's reply in the Transcendental Aesthetic which is, as far as we know, the only reply to Mendelssohn's original criticism (of 10 years previous) communicated to him. Moreover, of any section in the KrV , the Aesthetic would have cost Mendelssohn the least effort to comprehend, seeing as he was already familiar enough with the doctrine of sensibility as presented in the Dissertation . In fact, as I will argue in this section, not only was Mendelssohn familiar with Kant's response, but the key argument in the fi rst part of Morgenstunden aims at nothing less than a full refutation of the pretensions of idealism, including that elaborated in the KrV . Accordingly, Mendelssohn begins by challenging Kant's distinction between transcendental idealism and the empirical variety by arguing that the Kantian, no less than the naïve empirical idealist, remains committed to the falsity of our cognitions of external things. With this result in hand, Mendelssohn turns to refi ning his original criticisms of Kant's idealism and then offers a new challenge to the coherence of the specifi cally Kantian posit of a cognitively inaccessible transcendental object. Mendelssohn's critical discussion of idealism occurs, for the most part, in lectures 6 and 7 of Morgenstunden and it begins, innocuously enough, with a comparison of dualism and idealism. In lecture 6, Mendelssohn enumerates at least four propositions which the dualist and the idealist both accept. First, the idealist agrees with the dualist that "the thoughts that come about in him, as alterations of himself, have an ideal existence of their own" (die Gedanken, die in ihm vorgehen, als Abänderungen seiner selbst, ihr idealisches Daseyn haben) from which follows, second, "that he himself, as the subject of these alterations, is actually on hand" ( JubA 3.2:55; dass er selbst, als die Subject dieser Abänderungen, würklich vorhanden sey). Third, insofar as the idealist is not an egoist admitting only the existence of a single thinking substance, namely himself (a position Mendelssohn dismisses as absurd 16 ), then he agrees with the dualist who accepts the actual existence of thinking beings, limited like himself, but distinct from him ( JubA 3.2:55–56). Fourth, and fi nally, the idealist 15 For more details on Kant's Critical response, see Falkenstein, Kant's Intuitionism , 348–52. 16 See JubA 3.2:102–3. 166 C.W. Dyck no less than the dualist distinguishes two series of things, or representations, within the totality of his own cognition: the subjective which is truly only in him, and the objective "that is common to all thinking beings according to their standpoint and viewpoint" ( JubA 3.2:56; die allen denkenden Wesen nach ihrem Standorte und Gesichtspunkte gemeinschaftlich ist). The subjective series is ordered in accordance with the "law of wit, of imagination, or of reason" (nach dem Gesetze des Witzes, der Einbildungskraft oder der Vernunft) inasmuch as representations follow one another on the basis of having been perceived previously at the same time or of containing the same marks, whereas the objective series of representations is ordered according to laws of nature or causal connection (cf. JubA 3.2:46). Signifi cantly, for Mendelssohn the difference between the dualist and idealist does not necessarily lie in the fact that the former admits a world of objects external to us corresponding to our representations whereas the latter denies this. Instead, the dualist and idealist part company when it comes to the truth of our representations of objects as, for instance, extended. The key question, then, is whether "these characteristics also assert the truth?" ( JubA 3.2:56; sagen diese Merkmaale auch die Wahrheit aus?), and the dualist takes our representations of things as extended to contain truth, whereas the idealist dismisses such representations as false and illusory: Outside us, are there actually sensory objects that contain the reason why, in a waking state, we think the series of objective concepts so and not otherwise? The full repertoire of our objective ideas also contains life-less substances, corporeal entities, that exhibit themselves as something to be found outside us. Is this exhibition of them also true for itself? "No!" answers the idealist, "it is the short-sightedness of our sensory knowledge that we think so; it is a sensory illusion, the ground of which is to be found in our incapability." 17 As explained earlier in Morgenstunden , a representation contains truth only insofar as that representation has its ground in a positive power of thinking in the soul rather than mere incapacity (cf. JubA 3.2:34). Thus, the dualist will uphold the truth of our representations of objects as extended because he will take the ground for our representation of objects in that way to lie in a positive power of thinking in accordance with which the soul represents something to itself that is not merely a function of its perspective or limitation. 18 Mendelssohn's idealist, on the other hand, 17 JubA 3.2:56: "Giebt es würklich ausser uns sinnliche Gegenstände, die den Grund enthalten, warum wir uns im wachenden Zustande die Reihe der objectiven Begriffe so und nicht anders denken? Der Inbegriff unsrer objectiven Ideen enthält auch leblose Substanzen, körperliche Wesen, die sich uns als ausser uns befi ndlich darstellen. Hat diese Darstellung auch Wahrheit für sich? Nein! antwortet der Idealist, es ist Kurzsichtigkeit unsrer sinnlichen Erkenntniss, dass wir so denken; es ist Sinnentäuschung, davon der Grund in unserm Unvermögen anzutreffen ist." 18 JubA 3.2:56–57: "Meanwhile, not everything in the manifold depictions of [corporeal substances] is perspective; not everything is the outcome of our limitedness and our confi ned viewpoint . . . He [the dualist] believes rather that much in the senses follows from his soul's positive power of thinking and thus is the truth." ( Indessen sey in den mannichfaltigen Abbildungen derselben nicht alles Perspective; nicht alles Folge unsrer Eingeschränktheit . . . Er glaubt vielmehr, vieles in denselben folge aus der positiven Denkungskraft seiner Seele, und sey also Wahrheit .) 1678 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... will deny the truth of all representations of objects as extended because he will claim that such a representation of the object is wholly a function of the soul's incapacity, whether or not there actually is an object independent of us. Mendelssohn's purpose in thus re-drawing the lines separating the dualist from the idealist is clearly to undermine Kant's attempted distinction of transcendental from empirical idealism. For Kant, our representations of objects as extended have no ground in those objects considered as they are in themselves, since space cannot be taken to pertain to things considered in that way; rather, the form of these representations, as an a priori form of sensibility, has its seat in the subject. Given that these forms do not themselves have any ground in objects, representations of objects in accordance with them cannot be taken to proceed from a positive power of thinking but must be grounded merely in the soul's incapacity, in its inability to cognize things as they are in themselves; thus, according to Mendelssohn, the Kantian idealist, just like the garden-variety empirical idealist, must ultimately dismiss sensory representations as false and illusory. 19 Having denied any signifi cant difference between transcendental and empirical idealism, Mendelssohn now sets out to "refute the project of the idealists" in the second half of lecture 6 of Morgenstunden . And while Mendelssohn's criticism, unsurprisingly given its primary target, revisits the points originally raised against Kant in the letter of late 1770, he now presents these in a more systematic form with considerable refi nement and added detail. Mendelssohn's fi rst objection to Kant had turned on the fact that the subjectivity of time cannot be maintained when fi nite minds are considered as "objects of representations both those of God and those of their fellow minds." In Morgenstunden , Mendelssohn will advance a similar line of argument, this time focusing on the way in which the comparison of a given subject's representations with the representations of other fi nite minds and God's can serve to counter any lack of assurance on the part of the subject regarding the truth of those representations. Mendelssohn admits in Morgenstunden just as he had in the letter to Kant of 1770 that, from the point of view of the subject, the question of idealism cannot be settled; instead, traction is only gained on the idealist once the agreement between my representations and those of other representing minds is taken into account. Given this agreement, along with the unlikelihood that such agreement would have its ground in the incapacity of the subject rather than in a common external object, we can infer the existence of objects outside of us by means of an induction: The more, however, that fellow human beings agree with me in fi nding these things to be so, the greater becomes the certainty that the ground of my belief is not to be found in my particular situation. It must lie either in the positive power of thinking and thus be a true exhibition [of something] or in the common limitations of all human knowledge. The probability of the latter case decreases if I become convinced that even animals know 19 Contrast Lewis White Beck ( Early German Philosophy: Kant and his Predecessors [Cambridge, MA: Belknap, 1969], 337–39) and Beiser ( Fate of Reason , 105–6), both of whom take Mendelssohn simply to misunderstand Kant's idealism as Berkeleyian. 168 C.W. Dyck things in this way and not otherwise . . . If we could be convinced that even beings of a higher order than ourselves think the things in this way and not otherwise . . . then the certainty with which we know the existence of things outside us would increase to the highest degree of evidence. 20 Mendelssohn recognizes that such an induction could hardly satisfy the idealist so long as it remains incomplete. It will not suffi ce simply to note an agreement among the representations of human, animal, and even higher fi nite minds, but this agreement must be shown to obtain for all thinking beings, including God. What must be demonstrated, then, is not simply that God exists, but also that the way in which objects must be exhibited to God agrees with the way in which they are represented to us, not insofar as God represents such objects spatially (because according to Mendelssohn that is not the case 21 ), but insofar as God's exhibitions can be shown to differ only in that they are perfectly distinct whereas our representations are for the most part confused. Having shown all this, we can be fully secure in the inference to the existence of some object existing independently of us as the grounds of our representations since it will then be made by means of a complete induction: If we shall have convinced ourselves of the existence of the supreme being and its properties, then a way will also present itself of making for ourselves some concept of the infi nity of the supreme being's knowledge and from this truth, along with several others, perhaps in a scientifi c, demonstrative manner, of refuting the pretensions of the idealists and of proving irrefutably the actual existence of a sensory world outside us. 22 Completing the induction in this way would show that some aspect of our representations of objects, namely, that aspect of our representation that differs from God's cognition only in being confused and limited in perspective, must have its ground in objects that are independent of us. It would follow that that aspect of our representation must proceed from a positive power of thinking in the soul, rather than mere limitation, and therefore be true. When the induction is completed, then, the idealist pretension that all such representations are false would be refuted. 20 JubA 3.2:54–55: "Je mehr Menschen aber mit mir übereinstimmen, diese Dinge so zu fi nden, desto grösser wird die Gewissheit, dass der Grund meines Glaubens nicht in meiner besondern Lage anzutreffen sey. Er muss entweder in der positiven Denkungskraft liegen, und also wahre Darstellung seyn; oder in den gemeinschaftlichen Schranken aller menschlichen Erkenntniss. Die Wahrscheinlichkeit des letzten Falles nimmt ab, wenn ich überführt werde, dass auch Thiere die Dinge so und nicht anders erkennen . . . Könnten wir überführt werden dass auch höhere Wesen als wir . . . so und nicht anders denken; so würde die Gewissheit, mit welcher wir das Daseyn der Dinge ausser uns erkennen, bis zur höchsten Evidenz heranwachsen." 21 See, for instance, JubA 1:311; Mendelssohn, Philosophical Writings , 291. 22 JubA 3.2:55: "Wenn wir uns vom Daseyn eines höchsten Wesens und von seinen Eigenschaften überzeugt haben werden; so wird sich ein Weg zeigen, uns auch einigen Begriff von der Unendlichkeit seiner Erkenntniss zu machen; und von dieser mit mehrerer Wahrheit, vielleicht auf eine wissenschaftliche demonstrative Art, das Vorgeben der Idealisten zu widerlegen, und das würkliche Daseyn einer sinnlichen Welt ausser uns unumstösslich zu beweisen." 1698 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... Mendelssohn thus lays out in lecture 6 of Morgenstunden what exactly is needed in order to refute the idealist project, but he does not immediately supply the promised argument. Indeed, Mendelssohn only completes his refutation in lecture 16, in the new argument for God's existence on the basis of the limits of our self-knowledge, though this argument's connection to the earlier refutation has been overlooked. 23 Mendelssohn begins his proof by setting out from the perception that "I am not merely what I distinctly know of myself or, what amounts to the same, there is more to my existence than I might consciously observe of myself." 24 What Mendelssohn intends by this principle is not simply that the I, the "subject of thoughts" is not known completely since I am not always conscious of it, but also that the entire content of the representations that are attributed to this subject, including the content of my representations of objects, is not distinctly cognized by me since in every case these representations are limited by my unique perspective on them. This principle, Mendelssohn claims, is no less evident than my feeling of my own existence inasmuch as it cannot possibly be the result of any sensory deception nor of an incomplete induction. In addition to this principle, Mendelssohn provides another that concerns the modalities of thought: "Now I maintain not only that everything possible must be thought to be possible by some thinking being, but also that everything actual must be thought to be actual by some thinking being." 25 Against the charge that the latter principle in particular moves from what can be the case to what is actually the case in inferring from the (apparently unobjectionable) claim that any actuality is necessarily think able to the claim that an actuality is necessarily thought , Mendelssohn argues that the fact that something is thinkable presupposes that that thing is actually thought. As he writes, "what is actually on hand still lies at bottom in every case and the possibility ascribed to it is the thought that under different circumstances the present make-up would be modifi ed in another way," 26 which is to say generally that possibility presupposes actuality, and so that what is necessarily thinkable must also actually be thought. Whatever the cogency of this reasoning, Mendelssohn holds that once these principles are conceded, not only does the existence of a supreme intellect follow, but it also follows that this intellect must be conceived as distinctly exhibiting to 23 In fact, the argument is intended to reply to Lessing who would admit "a God outside the world but deny a world outside of God" ( JubA 3.2:116). See "Über die Wirklichkeit der Dinge ausser Gott" in Gotthold Ephraim Lessings sämtliche Schriften , ed. Karl Lachmann and Franz Muncker, 14:292–93 (Berlin: De Gruyter, 1968); Altmann, Moses Mendelssohn , 692–93. 24 JubA 3.2:141: "Ich bin nich blos das, was ich von mir deutlich erkenne, oder, welches eben so viel ist: Zu meinem Daseyn gehört mehr, als ich mit Bewusstseyn von mir einsehe." 25 JubA 3.2:142: "Nun behaupte ich, nicht nur alles mögliche müsse als möglich, sondern auch alles Würkliche müsse als würklich, von irgend einem denkenden Wesen gedacht werden." 26 JubA 3.2:144–45: "Immer noch liegt bey dergleichen Behauptung das würklich Vorhandne zum Grunde, und die ihm zugeschriebene Möglichkeit ist der Gedanke, dass unter andern Umständen die gegenwärtige Beschaffenheit desselben anders modifi cirt seyn würde." 170 C.W. Dyck itself "everything that pertains to my existence," that is, the complete content of my representations without any of the distortions wrought by my own limitations. 27 In this way, this new "scientifi c proof for God's existence" also demonstrates that the same substances that I cognize only imperfectly must be exhibited to God, albeit as prototypes , or originals, without limitation to a particular perspective and without any attendant confusion (cf. JubA 3.2:88). This proof thus completes the induction on the basis of which we can infer from the agreement among the representations of all thinking beings to some ground in a common object for that agreement and, therefore, to the source of our representations of that object in a positive power for thinking. 28 This fi rst, longer argument against the idealist, then, develops one line of criticism already introduced in Mendelssohn's letter to Kant of 1770. A second, shorter argument presented at the conclusion of lecture 6 develops another point Mendelssohn had brought up in that letter: the claim that once the reality of time is granted with respect to the representation, its reality for "the model and prototype of representations in the world" also follows. In Morgenstunden , this objection is tabled in response to the idealist's assertion that even if the desired agreement among thinking beings in their representations of objects as extended and mobile could be demonstrated, the existence of such an extended, mobile substance would not follow: "But what sort of properties," asks the idealist, "do you attribute to this substance? Are not all sensory properties that you ascribe to it mere modifi cations of what transpires in you yourself? You say, for example, that matter is extended and moveable. But are extension and movement something more than sensory concepts, alterations of your power of 27 JubA 3.2:142–43: "If these propositions are allowed, then it obviously follows that an entity must be on hand which represents to itself in the most distinct, purest, and most thoroughgoing manner everything that pertains to my existence. No limited knowledge would contain everything that pertains to my actual existence. A contingent being's consciousness and distinct discernment, indeed, that of all contingent beings altogether, do not reach as far as the existence of a single speck of the sun . . . There must, therefore, be one thinking being, one intellect that thinks in the most perfect way the sum-total of all possibilities [i.e., all that is thinkable] as possible and the sum-total of all actualities [i.e., all that is actually thought] as actual." (Werden diese Sätze eingeräumt, so folget auf eine handgreifl iche Weise, dass ein Wesen vorhanden seyn müsse, welches alles, was zu meinem Daseyn gehöret, auf das allerdeutlichste, reinste und ausführlichste sich vorstellet. Jede eingeschräkte Erkenntniss würde nicht alles enthalten, was zu meinem würklichen Daseyn gehört. Das Bewusstseyn und die deutliche Einsicht eines zufälligen Wesens, ja aller zufälligen Wesen zusammen genommen, reichet nicht so weit, als das Daseyn eines einzigen Sonnenstäubleins . . . Es muss also ein denkendes Wesen, einen Verstand geben, der den Inbegriff aller Möglichkeiten, als möglich, den Inbegriff aller Würklichkeiten, als würklich auf das vollkommenste denket.) 28 JubA 3.2:55: "If we could be persuaded that the supreme intellect exhibited to itself the things outside us to itself as actual objects, then our assurance of their existence would have attained the highest degree of evidence and there would be no further increase that it might undergo." (Wenn wir überführt seyn könnten, dass der allerhöchste Verstand sich die Dinge ausser uns, als würkliche Objecte darstellte; so würde unsre Versicherung von ihrem Daseyn den höchsten Grad der Evidenz erlangt haben, und keinen fernern Zuwachs mehr leiden.) 1718 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... representation, of which you are conscious? And how are you able to transpose these properties, as it were, from yourself and ascribe them to a prototype that is supposed to be found outside you?" 29 This is an important criticism, since it challenges the relevance of Mendelssohn's (at this point) promised argument to the idealist position it is intended to refute: even if it can be shown that the objects that we represent as spatial are exhibited to God as actually existing, the most that this can demonstrate is that the objects we think as, for instance, extended and moveable exist without requiring any further attribution of extension and moveability to some substance. Mendelssohn dismisses this objection, however, claiming that the idealist is making far too much of a merely linguistic distinction: "If this is the diffi culty," the dualist replies, "then it lies more in the language than in the thing itself. If we say, a thing is extended, is moveable, then these words have no other meaning than this: a thing is constituted in such a way that it must be thought as extended and moveable. It is one and the same, according to language as well as the concept, to be A and be thought of as A ." 30 While perhaps misleadingly presented, Mendelssohn's claim here does not amount to the naïve idealistic identifi cation of the being of an object with its being thought; rather, his claim is that the fact that we necessarily think an object as extended implies that there must be something (i.e., some feature or property) in the object in virtue of which we are necessitated to think it in this way. This point becomes clearer in the lines which immediately follow the previous passage: "if we say that matter is extended, is moveable, is impenetrable, we are of course saying nothing more than that there are prototypes outside us that exhibit themselves as extended, moveable, and impenetrable, and exhibit themselves as such in each thinking being" (my emphasis). 31 That some feature in the prototype serves as the ground for our representations of objects as extended implies that these representations are capable of some degree of truth since in that case our representations do not proceed wholly from our limitation but are, at least in part, a function of a positive power for thinking in the soul which it would therefore have 29 JubA 3.2:57: "Was für Eigenschaften aber, fragt jener, legt ihr dieser Substanz bey? Sind nicht alle sinnlichen Eigenschaften, die ihr derselben zuschreibt, blosse Modifi cationen, die in euch selbst vorgehn? Ihr sagt, z.B. die Materie sey ausgedehnt und beweglich. Sind aber Ausdehnung und Bewegung etwas mehr, als sinnliche Begriffe, Abänderungen eurer Vorstellungskraft, deren ihr euch bewusst seyd; und wie könnt ihr diese gleichsam aus euch hinaustragen, und einem Urbilde zuschreiben, das ausser euch befi ndlich seyn soll?" 30 JubA 3.2:57: "Wenn diese die Schwierigkeit ist, erwidert der Dualist, so liegt sie mehr in die Sprache, als in der Sache selbst. Wenn wir sagen, ein Ding sey ausgedehnt, sey beweglich; so haben diese Worte keine andre Bedeutung, als diese: ein Ding sey von der Beschaffenheit, dass es als ausgedehnt und beweglich gedacht werden müsse. A seyn, und als A gedacht werden, ist der Sprache, so wie dem Begriffe nach, ebendasselbe." 31 JubA 3.2:57: "Wenn wir also sagen: die Materie sey ausgedehnt, sey beweglich, sey undurchdringlich; so sagen wir freylich weiter nichts, als: es gebe Urbilder ausser uns, die sich in jedem denkenden Wesen als ausgedehnt, beweglich und undurchdringlich darstellen." 172 C.W. Dyck in common with God. 32 Accordingly, it makes no difference, as far as refuting the idealist is concerned, whether an object is extended or is only constituted in a way that it is (necessarily) thought as such by all fi nite thinking beings since either way some feature in the object itself serves as the ground of (the truth of) our representations. In addition to refi ning his previous objections to the idealism of the Dissertation , Mendelssohn offers a new criticism in lecture 7, which specifi cally addresses Kant's idealism as elaborated in the KrV . As Mendelssohn writes: Recently, an adherent of the spiritual system with whom I engaged in debate about this matter said: "Is it not rather you yourself [i.e., the dualist] who occasions this linguistic confusion and seeks to entangle us in it? All of the properties ascribed by you to this prototype are, by your own admission, mere accidents of the soul. We want to know, however, what this prototype itself is, not what it might do." 33 Here the transcendental idealist responds in kind to the dualist's accusation of a linguistic confusion by pointing out that the dualist mistakes the analysis of the effects of an object on the soul for the investigation of what that object, the prototype for our representations, might be considered in itself, where the idealist claims that this latter issue is in fact left untouched by the dualist. Of course, the transcendental idealist will not maintain that we can know anything about the thing considered in itself, since such a thing must lie outside the boundaries of our experience, but will nonetheless defend the posit of the thing in itself and even make a limited use of it as a boundary concept (cf. A255/B310-11). Against this challenge, Mendelssohn charges the Kantian idealist with attempting to introduce a transcendental distinction, that is, one between appearances and things in themselves, when no such distinction is warranted. Where the Kantian spots a distinct limitation of our capacity in our inability to cognize the thing in itself, Mendelssohn discerns a limitation that holds for any cognizing being in general and which thus has none of the profound epistemological implications Kant seems to think it does: Friend, I answered, if you are serious on this point, then it seems to me that you demand to know something that is in no way an object of knowledge. We stand at the boundary not only of human knowledge, but of all knowledge in general; and we want to go further 32 See JubA 3.2:87–88: "If it is conceded that truth is to be encountered in the [representation], truth that, with the perspectival aspect discounted, repeats itself in each subject, then it is a consequence of the power of representation and must exhibit itself in the supreme being, if there is such, in the purest light and without any admixture of perspective. If, however, this is so, then so too is the proposition: 'there exists, objectively and actually, such a prototype,' the purest and most undeniable truth." (Wenn zugegeben wird, dass in dem Gemählde Wahrheit anzutreffen, die sich, das Perspectivische abgerechnet, in jedem Subjecte wiederhohlt, so ist es eine Folge ihrer Vorstellungskraft, und muss sich in dem allerhöchsten Wesen, wenn es ein solches giebt, in dem reinsten Lichte und ohne Zumischung des Perspectiven, darstellen. Ist aber dieses; so ist auch der Satz: es existirt ein solches Urbild objectiv würklich, die reinste und unläugbarste Wahrheit.) 33 JubA 3.2:59: "Seyd ihr es nicht vielmehr selbst, sprach letzthin ein Anhänger des geistigen Systems, mit dem ich mich hierüber in Streit einliess: Seid ihr es nicht vielmehr selbst, der diese Verwirrung in der Sprache veranlasst, und uns darin zu verwickeln sucht? Alle Eigenschaften, die ihr diesem Urbilde zuschreibt, sind, eurem eignen Geständnisse nach, blosse Accidenzen der Seele. Wir wollen ja aber wissen, was dieses Urbild selber sey, nicht was es würke." 1738 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... without knowing where we are headed. If I tell you what a thing does or undergoes, do not ask further what it is. If I tell you what kind of a concept you have to make of a thing, then the further question "What is this thing in and for itself?" is no longer intelligible. 34 Mendelssohn's claim here that the thing in itself is no object of knowledge at all is not limited in its scope to fi nite thinking beings but applies to God as well. This is not to say, however, that God's cognition is limited in the same way that ours is; as Mendelssohn explains to the Kantian idealist, in asking about the constitution of the thing in itself, "you are inquiring about a concept that is actually no concept and therefore something contradictory." ( JubA 3.2:60–61; Ihr forschet nach einem Begriffe, der eigentlich kein Begriff, und also etwas Widersprechendes seyn soll.) Thus, Mendelssohn's point is that the Kantian contention that we lack cognition of the thing in itself implies no limits whatsoever to our, or any being's, cognition since any claim of knowledge about it on the part of any being would be incoherent. This counterargument is made rather clearer in the consideration of the semantics of questions in the Remarks and Additions appended to the Morgenstunden . There, Mendelssohn claims, a question is only permissible in any fi eld of investigation when an answer to that question is possible: "All questions must be answerable, they must contain incomplete sentences that can be transformed into a complete, intelligible and thinkable sentence through some possible answer." 35 Mendelssohn goes on to apply this general, proto-verifi cationist principle to the Kantian idealist's question regarding the properties of the thing in itself: What are things in and for themselves, outside of all sensations, representations, and concepts? This question belongs, as I believe, to the class of unanswerable questions. The incomplete proposition that it contains is: – Things outside of all sensations, representations, and concepts are in and for themselves = X . If the question is to be valid, this sentence must be made more complete, the unknown in it, must be capable of being transformed into something known, the X into A . . . Suppose therefore: Things outside of all sensations, representations, and concepts are = A . Now, in such a case, A obviously does not provide any more to think than X does . . . Thus, the sentence that is passed off as incomplete cannot be made complete through any possible answer. The question is in and for itself unanswerable. 36 34 JubA 3.2:59–60: "Freund, antwortete ich, wenn dieses euer Ernst ist; so dünkt mich ihr verlangt etwas zu wissen, das schlechterdings kein Gegenstand des Wissens ist. Wir stehen an der Gränze, nicht nur der menschlichen Erkenntniss, sondern aller Erkenntniss überhaupt; und wollen noch weiter hinaus, ohne zu wissen, wohin. Wenn ich euch sage, was ein Ding würket oder leidet; so fraget weiter nicht, was es ist. Wenn ich euch sage, was ihr euch von einem Dinge für einen Begriff zu machen habet; so hat die fernere Frage, was dieses Ding an und für sich selbst sey? weiter keinen Verstand." 35 JubA 3.2:170: "Alle Fragen müssen beantwortlich seyn; müssen unvollständige Sätze enthalten, die durch eine mögliche Antwort in vollständige, verständliche und denkbare Sätze verwandelt werden können." 36 JubA 3.2:170–71: " Was sind die Dinge an und für sich, ausser allen Empfi ndungen, Vorstellungen und Begriffen? Diese Frage gehört, wie ich glaube, zu der Klasse der unbeantwortlichen Fragen. Der unvollständige Satz, den sie enthält ist: – Die Dinge ausserhalb aller Empfi ndungen, Vorstellungen und Begriffe sind an und für sich = X. Dieser Satz muss, wenn die Frage gelten soll, sich vollständiger machen, das Unbekannte in demselben muss sich in etwas Bekanntes, das X in 174 C.W. Dyck The question posed by the idealist, then, cannot be answered as any possible answer would only end up ascribing to it the type of properties that are denied of it in advance; thus, it follows that not even God could claim to know the thing in itself. Without the posit of the thing in itself, there is no longer any reason to take our representations of objects to be due solely to the limitations imposed by our sensibility and so Kant's transcendental distinction between appearances and things in themselves collapses. Contrary, then, to what we might expect from someone who professed all but a passing familiarity with the latest philosophical ideas, Mendelssohn had refi ned his original criticisms of Kant's idealism, and even formulated a novel challenge to the very foundations of the more sophisticated doctrine elaborated in the KrV . 37 3 Kant's Replies to Mendelssohn These developments in Mendelssohn's criticism were not lost on Kant, although it would seem that he did not animadvert to them immediately. Mendelssohn sent Kant a copy of Morgenstunden along with a letter dated October 16, 1785 in which he praises the tolerant spirit of Kant's Critical philosophy, in that it permits "everyone to have and to express opinions that differ from your own," after asserting "that our basic principles do not coincide" ( AA 10:413). Evidently, Kant was unsettled enough by this mere suggestion of a new Mendelssohnian criticism (perhaps recalling how long it had taken to craft a satisfactory reply to the previous one) that he very quickly "resolved to refute Mendelssohn," as Hamann fi rst reports in a portion of a letter to Jacobi with a date of October 28, 1785. 38 Kant soon changed his mind, however, and it is not unlikely that a letter from C. G. Schütz dated November 13, 1785 had something to do with it. In the letter, Schütz draws Kant's attention to the self-deprecating passage in the Preface of Morgenstunden and hastily concludes that "no new arguments against the Critique will show up in his book" ( AA 10:423). Whatever the cause, Kant quickly abandoned his previous A verwandeln lassen . . . Setzet also: Die Dinge ausserhalb aller Empfi ndungen, Vorstellungen und Begriffe sind = A. Nun giebt A in diesem Falle offenbar nicht mehr zu denken, als X . . . Der für unvollständig ausgegebene Satz kan also durch keine mögliche Antwort vollständig gemacht werden. Die Frage ist an und für sich selbst unbeantwortlich." 37 Accordingly, C.G. Schütz, in a review of Mendelssohn's text (see below), asserts that Mendelssohn's claim that he was unable to come to terms with Kant's KrV because of a nervous debility might be taken as a piece of Socratic irony, were the effects of this debility not so well known: on this see Altmann, Moses Mendelssohn , 675; and Erdmann, Kant's Kriticismus , 122. Regarding Mendelssohn's familiarity with Kant's KrV , see also JubA 3.2:210 where Mendelssohn corrects Jacobi's misinterpretation of Kant's account of consciousness (I am grateful to Anne Pollok for this reference). 38 Hamann, Briefwechsel (ed. A. Henkel. Frankfurt: Insel-Verlag, 1975), 6:107. This resolution is repeated in a letter to Herder of November 9, 1785 (6:127). See also Biester's letter to Kant of November 8, 1785 ( AA 10:417). Indeed, that Kant was expected to refute Mendelssohn's proof for the existence of God was even printed in the Gothaishe gelehrte Zeitungen in January of 1786 (cf. AA 10:437). 1758 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... plan of a full rebuttal, as reported by Hamann in a letter to Jacobi of November 28, 1785. 39 Nonetheless, Kant appears to have sent a couple of paragraphs of comments in reply to Schütz which, along with Schütz's own review, were subsequently published in the Allgemeine Literatur-Zeitung in the January issue of 1786, the month of Mendelssohn's death. In those paragraphs, Kant focuses on Mendelssohn's proof for the existence of God in lecture 16, at the root of which Kant discerns the pernicious infl uence of transcendental illusion. Referring to Mendelssohn's claim that "something is conceivable only if it is actually conceived ," or as Mendelssohn also puts it, that "without a concept no object really exists," ( AA 10:428 – Kant's emphases), 40 Kant argues that, lacking the benefi t of a critique of reason, Mendelssohn is doomed to confl ate the distinct senses in which this latter principle can be taken. It can be taken, namely, either as expressing " merely subjective conditions of [reason's] employment" (blos subjectiven Bedingungen ihres Gebrauchs), that is, a need of reason, or as expressing subjective conditions "by means of which something valid about objects is indicated" ( AA 10:428 – my initial emphasis; dadurch etwas vom Objecte gültiges angezeigt wird). Insofar as Mendelssohn's principle is taken to apply to sensible intuitions, then the claim that no object can be taken to exist without a concept (i.e., a pure concept of the understanding) can be admitted. Unfortunately, Mendelssohn seeks to apply this claim beyond the bounds of our experience and in so doing he is misled by that transcendental illusion in accordance with which merely subjective conditions are mistaken for conditions of objects (cf. A396), a criticism that Kant will also level against Mendelssohn in his essay "What does it mean to orient oneself in thinking?" of the following year. 41 According to Kant's verdict, then, Mendelssohn's text is a "masterpiece of the deception of reason" but one that "provides us with the most splendid occasion and at the same time challenge to subject our faculty of pure reason to a total critique" ( AA 10:428). In any case, no mention is made of Mendelssohn's criticisms of Kant's idealism: as Hamann reports in a letter to Jacobi of December 14, 1785, Kant had at this point determined that "the Morgenstunden do not actually concern him directly, as he had initially thought." 42 Kant did not long overlook Mendelssohn's criticism, however. In a letter of March 26, 1786, Ludwig Heinrich Jakob wrote Kant to announce his own intentions to write a rebuttal of the Morgenstunden owing to the fact that it "is thought to have dealt a serious blow to the Kantian critique" ( AA 10:436; als ob durch diese Schrift der Kantschen Krit. ein nicht geringer Stos versetzt wär). Jakob fi nds this hard to fathom, given Mendelssohn's professed unfamiliarity with Kant's thought, but even so he suspects one passage in particular to be "intended as an arrow aimed against your Critique ," and he directs Kant to the passage in lecture 7 in which Mendelssohn 39 Hamann, Briefwechsel , 6:152. 40 See JubA 3.2:145: "ohne Begriff [ist] kein Gegenstand wirklich vorhanden." 41 As Erdmann has noted ( Kant's Kriticismus , 145n), this criticism is found almost word-for-word in the later essay, see in particular AA 8:138n. Erdmann was the fi rst to attribute these comments to Kant; see Kant's Kriticismus , 144–46. 42 Hamann, Briefwechsel , 6:181. 176 C.W. Dyck accuses the Kantian idealist of holding out the possibility of knowing "something [i.e., the thing in itself] that is absolutely not an object of knowledge" ( AA 10:437). In his reply of May 26, 1786, Kant denies the rumours that he is still planning a refutation of the Morgenstunden , and encourages Jakob to pen his own, but having now had his attention drawn to Mendelssohn's new criticism, he offers to contribute "a suffi cient rebuke" (eine hinreichende Zurechtweisung) of Mendelssohn to Jakob's analysis ( AA 10:450). Kant's essay, dated August 4, 1786, was included after the Preface of Jakob's Prüfung des Mendelssohnschen Morgenstunden and in it Kant defends the posit of something standing outside of experience about which we can know nothing from Mendelssohn's charge that any question regarding "what this thing is in and for itself" would be nonsensical. Kant begins by asserting that a survey of our sensible cognition reveals that it never penetrates to the internal properties of objects but is limited to relations. Our knowledge of, for instance, corporeal nature is limited to cognition of space, which is merely the condition of external relations; to cognition of objects in space; and to cognition of motion and moving force, which simply involve changes in external relations. Given that our cognition falls well short of a cognition of the internal properties of things, that is, of things as they are independent of any such relations, Kant claims that the question as to what these objects might be considered in that way is at least a reasonable one ( AA 8:153). Anticipating the challenge on the part of Mendelssohn's defenders to provide some criterion for distinguishing between putative properties of things in themselves and those of appearances, Kant remarks that such a criterion is readily available and, indeed, already surreptitiously employed by Mendelssohn and others in arriving at the concept of God: You think in [God] unadulterated true reality, that is something that is not merely opposed to negations (as one commonly takes it), but also and primarily to realities in appearance ( realitas Phaenomenon ), such as all must be that are given to us through the senses and are called realitas apparens . . .. Now reduce all these realities (understanding, will, blessedness, power) in terms of their degree, they will always remain the same as far as their type (quality) is concerned, and in this way you will have properties of things in themselves that you can also apply to other things outside of God. 43 To Mendelssohn's criticism of his transcendental idealism in Morgenstunden , then, Kant counters that the question as to the nature of the thing in itself is perfectly sensible, even if we must admit that it cannot be answered; moreover, one means for distinguishing between the properties of things in themselves and of appearances is already presupposed, in some form, by Mendelssohn. Kant is certainly correct in claiming that Mendelssohn himself makes use of some criterion for distinguishing sensible realities from those that belong to God. 43 AA 8:154: "Ihr denkt euch in ihm [Gott] lauter wahre Realität, d.i. etwas, das nicht bloss (wie man gemeiniglich dafür hält) den Negationen entgegen gesetzt wird, sondern auch und vornehmlich den Realitäten in der Erscheinung ( realitas Phaenomenon ), dergleichen alle sind, die uns durch Sinne gegeben werden müssen und eben darum realitas apparens . . . genannt werden. Nun vermindert alle diese Realitäten (Verstand, Wille, Seligkeit, Macht etc.) dem Grade nach, so bleiben sie doch der Art (Qualität) nach immer dieselben, so habt ihr Eigenschaften der Dinge an sich selbst, die ihr auch auf andere Dinge ausser Gott anwenden könnt." 1778 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... For instance, in the prize essay "On Evidence in Metaphysical Sciences," Mendelssohn had done just this even though he does not put it in precisely the same terms as Kant: Of the properties of things outside us, we never know with convincing certainty whether they are realities or mere appearances and, at bottom, depend upon negations; indeed, in the case of some of them, we have reason to believe that they are mere appearances. Thus, we can ascribe none of these properties to the Supreme Being and must absolutely deny him some of them. Belonging to the latter group are all qualitates sensibiles that we have reason to believe are not to be found outside us as they seem to us thanks to our sensuous, limited knowledge and that, therefore, are not realities. 44 While admitting this, however, Mendelssohn need not accept Kant's inference that he is thereby also committed to holding the question regarding the constitution of things in themselves to be a meaningful one. The reason for this is the very one suggested by Kant himself in his rebuke, namely, that "if we were acquainted with the effects of things that could in fact be properties of a thing in itself, then we would not be permitted to ask further what the thing might yet be outside of these properties" (my emphasis). 45 As Mendelssohn had claimed in "On Evidence," we can gain cognition of the properties of things in themselves through a direct acquaintance with the soul's capacities, where the concepts thus acquired are subsequently applied to such objects, and in particular to God: But what then are the properties of things, of which we are able to say with certainty that they are actual realities? None other than our soul's capacities. Our cognitive faculty, for example, cannot possibly be an appearance. For an appearance is nothing other than a concept, the constitution of which must in part be explained by the ineptitude of our knowledge . . . Thus we can rightly ascribe to the Supreme Being all our cognitive capacities, if we abstract from the defi ciencies and imperfections that cling to them, and we can revere in him unfathomable reason, wisdom, justice, benevolence, and mercy. 46 44 JubA 1:309: "Wir wissen von den Eigenschaften der Dinge ausser uns niemals mit überzeugender Gewissheit, ob sie Realitäten, oder blosse Erscheinungen sind, und im Grunde sich auf Negationen stützen, ja von einigen haben wir Grund zu glauben, dass es blosse Erscheinungen sind. Daher können wir keine von diesen Eigenschaften dem allerhöchsten Wesen zuschreiben, und einige müssen wir ihm schlechterdings absprechen. Von der letzten Gattung sind alle Qualitates sensibiles, von welchen wir mit Grunde glauben, dass sie ausser uns nicht so anzutreffen sind, wie sie uns, vermöge unserer sinnlichen eingeschränkten Erkenntnis scheinen, und also keine Realitäten sind" (see Mendelssohn, Philosophical Writings , 290). 45 AA 8:154: "Freilich, wenn wir Wirkungen eines Dinges kennten, die in der That Eigenschaften eines Dinges an sich selbst sein können, so dürften wir nicht ferner fragen, was das Ding noch ausser diesen Eigenschaften an sich sei; denn es ist alsdann gerade das, was durch jene Eigenschaften gegeben ist." 46 JubA 1:310–11: "Aber welches sind denn die Eigenschaften der Dinge, von welchen wir mit Gewissheit sagen können, dass sie würkliche Realitäten sind? keine andere als die Fähigkeiten unserer Seele. Unser Erkenntnisvermögen z. B. kann unmöglich eine Erscheinung seyn. Denn eine Erscheinung ist nichts anders, als ein Begrif, dessen Beschaffenheit zum Theil aus dem Unvermögen unserer Erkenntnis erkläret werden muss . . . Daher können wir dem allerhöchsten Wesen alle unsere Erkenntnisvermögen, wenn wir von den Mängeln und Unvollkommenheiten abstrahiren, die ihnen ankleben, mit Rechte zuschreiben, und also in ihm die unergründliche Vernunft, Weisheit, Gerechtigkeit, Gütigkeit und Barmherzigkeit verehren" (see Mendelssohn, Philosophical Writings , 290–91). 178 C.W. Dyck So, even though Mendelssohn employs a distinction between types of realities, as Kant had pointed out, because he takes the soul's own capacities as properties of things in themselves, he can claim that we can know such objects in this way even while we cannot claim to know their properties by means of the outer senses. Consequently, any inquiry into the constitution of the thing in itself that gives rise to our representations of these properties can, according to Kant's own lights, be justifi ably dismissed as pointless. Yet, as should be clear, Mendelssohn's account relies wholly on the assumption that the cognition we have of the soul amounts to a cognition of a thing in itself, which assumption, insofar as it was thought to be threatened by the subjectivity of time, was just the original bone of contention between Mendelssohn and Kant. Disappointingly, it would seem that the philosophical dispute between the two has simply come full circle since its beginnings in 1770. Perhaps realising this, Kant would make one fi nal attempt in the second edition of the KrV to address what he took to be the root of Mendelssohn's hostility towards transcendental idealism. Already in the fi rst edition of that text, in his eventual reply to the objections of Mendelssohn and Lambert, Kant had offered an explanation for the uniform philosophical resistance to his idealistic conclusion in the Dissertation . As Kant noted, his doctrine does not observe any distinction in the ontological status of time and space, nor of their respective objects; rather time and space only pertain to objects considered as mere appearances, and as such both must be denied of objects insofar as they are considered as they are in themselves (cf. A38/B55). The epistemological consequence of this ontological equivalence, as far as Mendelssohn and Lambert were concerned, was that the existence of the objects of inner experience, the thinking subject and its states, could no longer be known immediately but their existence (as things in themselves) could at best only be inferred, like the existence of objects of outer experience, from their appearances. This result, however, contradicts the Cartesian presumption that Mendelssohn and Lambert share, namely, that the reality of the objects of inner experience, as opposed to those of outer experience, is immediately known. Indeed, this is something Kant had already recognized in his letter to Herz in 1772 when he wonders why none of his critics have raised a parallel challenge concerning the objects of outer sense (cf. AA 10:134), but in the fi rst edition of the KrV Kant continued to discern this Cartesian presupposition lurking behind these criticisms: They did not expect to be able to demonstrate the absolute reality of space apodictically, since they were confronted by idealism, according to which the reality of outer objects is not capable of any strict proof; on the contrary, the reality of the objects of our inner sense (of myself and my state) is immediately clear through consciousness. The former could have been mere illusion, but the latter, according to their opinion, is undeniably something real. 47 47 KrV A38/B55: "Die Ursache aber, weswegen dieser Einwurf so einstimmig gemacht wird und zwar von denen, die gleichwohl gegen die Lehre von der Idealität des Raumes nichts Einleuchtendes einzuwenden wissen, ist diese. Die absolute Realität des Raumes hofften sie nicht apodiktisch darthun zu können, weil ihnen der Idealismus entgegensteht, nach welchem die Wirklichkeit äusserer Gegenstände keines strengen Beweises fähig ist: dagegen die des Gegenstandes unserer innern Sinnen (meiner selbst und meines Zustandes) unmittelbar durchs Bewusstsein klar ist. Jene konnten ein blosser Schein sein, dieser aber ist ihrer Meinung nach unleugbar etwas Wirkliches." 1798 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... It is certainly the case that this Cartesian presumption lurks behind Lambert's and Mendelssohn's objections to Kant's Dissertation . This is most clearly evident in Lambert's assertion that "even an idealist must grant at least that changes really exist and occur in his representations" ( AA 10:107). While Mendelssohn does not provide an explicit endorsement of this claim in his letter to Kant, the earlier essay "On Evidence" leaves little doubt that he accepts it: "The skeptic can, indeed, generally be in doubt whether the things outside us are as we represent them to be . . . There is no doubt, however, that we represent them." 48 Unsurprisingly, Mendelssohn continued to adopt this Cartesian starting point in Morgenstunden . Already in the fi rst lecture, he writes: My thoughts and representations are the fi rst things of whose actuality I am convinced. I ascribe an ideal actuality to them insofar as they dwell inwardly in me and are perceived by me as alterations in my faculty of thinking. Each alteration presupposes something that is altered. I myself, then, the subject of this alteration, have an actuality that is not merely ideal but real. 49 Even so, what is important to note here is not only Mendelssohn's continued acceptance of this Cartesian presupposition after Kant had called attention to it, but also the particular way in which he persists in making use of it. As had been the case in the original objections to the Dissertation , our inner experience is not construed in terms of the perception of a given thought, but in terms of the experience of an alteration in our thoughts where the self is taken to be that which is altered: "Where there are alterations, there must also be a subject on hand that undergoes alteration. I think, therefore I am." 50 While Kant had made note of this Cartesian presupposition on the part of his opponents in the fi rst edition of the KrV , he did not take issue directly with it then. Rather, in the fourth Paralogism of the fi rst edition of the KrV , he had contented himself with showing that, while the immediacy of inner experience might follow naturally for the transcendental realist, the transcendental idealist is not similarly committed to it but can uphold the immediacy of both inner and outer experience and thereby avoid certain sceptical problems (cf. A375-6). Now recognizing the need for a more offensive strategy as he worked on the second edition of the KrV through the second half of 1786, and with his previous diagnosis of the root of the uniform opposition to his idealism in mind, it is not unlikely that Kant intended his own Refutation of Idealism, at least in part, to target the basis for Mendelssohn's 48 JubA 1:309: "Ueberhaupt kann der Sceptiker wohl in Zweifel seyn, ob die Dinge ausser uns so sind, wie wir uns dieselben vorstellen . . . Dass wir sie uns aber vorstellen . . ., darin fi ndet kein Zweifel statt" (see Mendelssohn, Philosophical Writings , 289). 49 JubA 3.2:14: "Das erste, von dessen Würklichkeit ich überführt bin, sind meine Gedanken und Vorstellungen. Ich schreibe ihnen eine ideale Würklichkeit zu, in so weit sie meinem Innern beywohnen, und als Abänderungen meines Denkvermögens von mir wahrgenommen werden. Jede Abänderung setzet etwas zum voraus, das abgeändert wird. Ich selbst also, das Subject dieser Abänderung, habe eine Würklichkeit, die nicht blos ideal sondern real ist." 50 JubA 3.2:43: "Wo Abänderungen sind, da muss auch ein Subject vorhanden seyn, das Abänderung leidet. Ich denke; also bin ich." 180 C.W. Dyck (and Lambert's) objections. 51 In his Refutation, Kant sets out to refute specifi cally "the problematic idealism of Descartes, who declares only one empirical assertion, namely I am , to be indubitable" (B274), though he notes that this form of idealism does not imply anything regarding the status of outer experience other than "our incapacity for proving an existence outside of us from our own by means of immediate experience" (B275). Evidently working from Mendelssohn's (and Lambert's) conception of inner experience as the experience of an alteration, or succession, of thinking states, Kant notes that something permanent is required in order to determine the temporal order of these states in accordance with the principle of the First Analogy (and, indeed, Mendelssohn concedes as much when he claims that alteration implies something that is altered). Kant proceeds to show that, in light of the doctrine of apperception presented in the Deduction, this persistent thing cannot be the I think , nor could it be an enduring inner intuition since that would merely beg the question as to the grounds of its determination in time; Kant thus concludes that "the consciousness of my own existence is at the same time an immediate consciousness of the existence of other things outside me" (B276). Applied against Mendelssohn, the Refutation shows that his root concern about transcendental idealism, its alleged demotion of inner experience and its objects to the same illusory status as outer experience, is unfounded relying as it does upon an ultimately untenable conception of inner experience. So, having identifi ed this unexpected idealist commitment (of a problematic sort) at the heart of Mendelssohn's attempted refutation of transcendental idealism, and having shown that this idealism is itself subject to refutation, Kant boasts that "the game that idealism plays has with greater justice been turned against it" (B276). This overlooked Mendelssohnian component of the background for Kant's Refutation of Idealism 52 is rather signifi cant in its implications for our understanding of Kant's argument. It has been assumed throughout the extensive commentary on the argument that Kant's target in the Refutation is the Cartesian external-world sceptic and that the argument is intended to answer the challenge originally posed by the Garve-Feder review, namely, to distinguish transcendental idealism from the empirical variety. 53 This is, no doubt, correct as far as it goes, and indeed we have even seen that in the Morgenstunden Mendelssohn begins by posing a similar, if 51 Interestingly, Caranti draws a similar connection between Kant's Refutation of Idealism and Lambert's original criticism of his Dissertation . As Caranti writes, referring to Lambert's claim that the idealist must at least admit the reality of alteration in the representing subject: "Perhaps this remark was Kant's inspiration for the Refutation" ( Kant and The Scandal of Philosophy: The Kantian Critique of Cartesian Scepticism [Toronto: University of Toronto Press, 2007], 132). While the Refutation applies equally to Lambert's and Mendelssohn's original objections, I take it that the later and more sophisticated challenge in Morgenstunden is the likelier "inspiration." 52 Contrast, for instance, Heidemann, Kant und das Problem des metaphysicschen Idealismus (Berlin: De Gruyter, 1998), 46n78. 53 See Heidemann, Kant und das Problem , 87–94. 1818 Turning the Game Against the Idealist Mendelssohn's Refutation of Idealism... more sophisticated, challenge to Kant. 54 Even so, it should be clear that the Refutation does not have to do solely with the mythical Cartesian external-world sceptic, but also targets the all-too real Leibnizian-Wolffi an metaphysician, like Mendelssohn, who would set out from the assumption of the priority of inner experience. Moreover, while Kant's Refutation does function to distinguish transcendental from empirical idealism, the above suggests that it only does so in the service of its overarching aim to remove one particularly stubborn obstacle to the acceptance of transcendental idealism, the presumed immediacy of inner experience, 55 and that this should be the Refutation's primary dialectical concern may explain why there is no mention of this doctrine among the premises. 56 Yet, without pursuing these narrowly Kantian issues any further, what should be clear from the foregoing is that Mendelssohn's criticism of Kant's idealism in Morgenstunden is much more rigorous, and proved far more influential, than has previously been thought. Instead of amounting to a last-gasp, stand-alone objection on the part of a cantankerous dogmatist (as Mendelssohn himself might like us to believe it is), Mendelssohn's objections to Kantian idealism develop criticisms already tabled in his fi rst encounter with Kant's doctrine of sensibility, and include a further challenge that evidences an understanding of Kant's increasingly sophisticated efforts to distinguish his position from a naïve sort of idealism. Kant himself, while initially dismissive of Mendelssohn's objections, was eventually persuaded of their signifi cance, and even paid them a fi tting tribute in devoting a new argument in the second edition of the KrV to refuting their presumed epistemological foundations. Without doubt, then, Mendelssohn profi ted from what he had read of the latest metaphysical ideas, little though that might have been; but neither can it be doubted that philosophers from Kant onwards have profi ted from reading, and contending with, Mendelssohn. 57 Bibliography Altmann, Alexander. Moses Mendelssohn: A Biographical Study . London: Routledge and Kegan Paul, 1973. Beck, Lewis White. Early German Philosophy: Kant and his Predecessors . Cambridge, MA: Belknap, 1969 54 Indeed, Mendelssohn was familiar with the notorious Garve-Feder review: in a letter to Elise Reimarus he writes, "Der Auszug, welchen Hr. Garve hat in der Bibliothek setzen lassen, ist mir zwar deutlich; allein Andere sagen, Garve habe ihn nicht recht gefasst" ( JubA 13:169). 55 While the same obstacle crops up in the Garve-Feder review, in its charge that Kant's idealism "denies the rights of inner sensation," this is apparently only because Kant claims "that the concepts of substance and actuality belong to outer sensation alone" ( Kant's Early Critics [Cambridge: Cambridge University Press, 2000], 58). 56 For a reading of the Transcendental Deduction that comes to a complementary conclusion regarding its anti-sceptical intentions, see Corey W. Dyck, "Kant's Transcendental Deduction and the Ghosts of Descartes and Hume," British Journal of the History of Philosophy , 19 (2011): 473–96. 57 I am grateful to Dietmar Heidemann for helpful comments on earlier drafts of this paper. 182 C.W. Dyck Beiser, Frederick C. The Fate of Reason: German Philosophy from Kant to Fichte . Cambridge, MA: Harvard University Press, 1987. 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