COREY DYCK | Kant and Rational Psychology | Oxford University Press 2014


By Corey Dyck

I am pleased to have the opportunity to respond to my critics, Andrew Brook, Colin Marshall, Scott Edgar, and Toni Kannisto. Their comments succeed in touching on many of the most significant themes of Kant and Rational Psychology (KRP), including my novel interpretation of the psychological illusion and errors exposed in the Paralogisms, my account of the innovative and distinctive character of the rational psychology of the eighteenth century German tradition, and my efforts to enrich our currently rather poor conception of the resources of philosophical rationalism. Altogether, they raise a variety of challenges—historical, interpretative, and philosophical—to my project, and in what follows, I will reply to each of my critics in turn.

1. Reply to Brook

In his critical discussion, Brook highlights a number of points in the Paralogisms chapter where my treatment says too little, or overlooks key details, such as the discussion of transcendental apperception, the doctrine of illusion and its potential relevance to current approaches to the mind, and aspects of Kant’s discussion of self-reference in the Second Paralogism. In addition, in the final section of his comments, Brook offers a pointed criticism of my reading of the Third Paralogism, in particular, of the basis for my claim that Kant allows that we are conscious of the identity of the subject over time. Accordingly, my response will be divided into two sections: in the first I will attempt to provide some justification and context for the shortcomings Brook’s identifies in my analysis, and in the second I will reply to Brook’s criticism of my reading of the Third Paralogism.

1.1 Transcendental apperception, illusion, and the Second Paralogism

Brook’s comments begin by setting out the differences in our approaches to understanding Kant’s Paralogisms. He offers an instructive contrast between approaching an historical text with an eye to mining it for new ideas and arguments that bring that work into dialogue with later discussions, and approaching that text with an eye to discerning how a philosopher engages with a certain intellectual tradition and exploring how it informs his or her own ideas. The distinction between approaches, which roughly correlates with the familiar distinction between ‘analytical’ and ‘contextual’ historical methodologies, has been much discussed of late, and KRP serves as a clear example of the latter sort of methodology (and, I think, of its potential success).

While distinct, however, these contrasting methodologies can yield mutually illuminating, and beneficial, results. Obviously, approaches that mine, in this case, Kant’s Critique of Pure Reason for anticipations of, and engagements with recent debates, help to keep Kant’s philosophical currency in circulation, which rising tide lifts all Kantian boats. Indeed, it is hard to imagine contemporary Anglo-American Kant scholarship being as vibrant today without, for instance, P.F. Strawson’s The Bounds of Sense. However, I view the historical approach to Kant as a helpful, and necessary, corrective to the enthusiasms that the former approach generates (which is not to say that the historical approach is not subject to various enthusiasms of its own). Most importantly, it works against the natural tendency of a revolutionary philosophical project (like the Kantian and the Cartesian philosophy to name only two) to erase, as it were, all traces of the tradition from which it nonetheless emerged. Such is the nature, I suppose, of revolutions, but the consequence of this is that in light of unfamiliarity with the antecedent tradition, it becomes difficult to determine what in Kant is in fact new. This is all to say (and Brook does not deny this, of course), that such contextual, historical investigations can contribute to our understanding of what is truly revolutionary in Kant’s thought, and as a result also help point the miner towards rich veins that might otherwise be overlooked.

With this in mind, we can turn to the specific issues with respect to which Brook claims I leave out important details. So, regarding transcendental apperception Brook points out that Kant’s discussion in the circle argument seems to anticipate later claims that ‘I’ functions as an essential indexical. Similarly, Brook’s analysis of the diagnosis of illusion brings Kant close, as mine does not, to the functionalist insight that an account of the mind’s functions does not illuminate the sorts of structures those functions are realised in. Finally, with respect to my analysis of the Second Paralogism, Brook emphasizes Kant’s realisation in connection with it that by means of transcendental apperception we refer to the self independently of any reference to properties that it has.

Brook is, of course, correct that I do not touch on these issues in KRP, or indeed, attend for the most part to the relevance of Kant’s views on apperception or the mind in general to issues in contemporary philosophy of mind and language. Nor is this something I will attempt to rectify here. I will, however, point out that this oversight is not because I do not recognise the value of, or interest in, such discussions. Rather, it is (partly) due to the fact that I doubted I could improve on the extant treatments (including Brook’s), but also because I recognised that previous interpretations have themselves neglected important details when it comes to Kant’s complex criticism in the Paralogisms chapter (not to mention his discussion of the soul in the Appendix to the Dialectic).

To illustrate, we might consider two of the examples Brook cites: Kant’s diagnosis of illusion, and the arguments canvassed in the second argument (which Brook labels ‘B’) discussed in the Criticism of the Second Paralogism. Concerning the former, previous accounts of psychological illusion ignored, or dismissed as implausible, Kant’s characterization of the basis of the rational psychologist’s error in terms of mistaking “the unity in the synthesis of thoughts” for a “perceived unity” (A402; my emphasis), that is, the conflation of an intellectual representation with an empirical representation. Indeed, this omission of the empirical character of the illusory appearance is evident in the formulation of the general psychological illusion that Brook offers, where “a general feature of experience [is taken] to be a property of the subject of experience”. Yet, understanding the illusion in terms of the apparent perception of the soul, as an object of inner experience, not only helps to make sense of otherwise mystifying formulations of psychological illusion in, for instance, the Prolegomena and various unpublished texts, but it also sheds light on the error committed by the rationalist metaphysician in each of the paralogisms, an error which Kant notoriously characterizes in terms of an empirical misuse of the categories with respect to the soul.[1] Given the illusory appearance of the soul as an object of inner experience, and given that the entire tradition of rational psychologists before Kant had fallen prey to just this temptation, the relevance, and importance, of this general account of error in the Paralogisms can be preserved.

The Second Paralogism offers useful confirmation of this. As Brook also notes, the ‘Achilles argument’ (which Brook labels the ‘A’ argument), and Kant’s rejection of the inference from the unity of a thought to the unity of the subject, has garnered the lion’s share of attention in the secondary literature. This has led commentators to overlook Kant’s innovative discussion of self-reference on which Brook himself focuses, but it has also distracted attention from the problematic syllogism itself and its connection to the psychological illusion that underlies the rational psychologist’s error in this case. As I show in KRP, despite its honorific title, the Achilles argument was not regarded by Kant as the only, or even the best, argument for the soul’s simplicity. Instead, Kant had already formulated at the time of the Dissertation an alternative argument for this conclusion by means of our immediate insight, through inner sense, into the unity of the subject (an argument which I dubbed the ‘Tortoise’ since Kant holds that the Achilles always stops short of proving what it does, namely, that the soul is simple as an object of inner sense). It is, I contend, this argument that is the target of Kant’s exposure of an error grounded on illusion as the misapprehension of the soul as a perceived unity is a function of its illusory appearance, which grounds the subsequent illicit empirical use of the concept of simplicity.

These details regarding Kant’s systematic criticism of the rational psychologist, and his perhaps unexpected characterization of the illusion and error involved, have been, as far as I can tell, nearly uniformly overlooked in previous discussions. This is due, I think, to the interpretative premium that has frequently been placed on the second internal requirement identified by Brook, namely that the Paralogisms aim at beating back temptations to over-interpret certain claims about the mind made in the Deduction. However, as I argue in KRP, to take this as the principal purpose of the Paralogisms is to overlook the fact that rational psychology, considered as a science of the soul conducted entirely a priori, is not the conception of the discipline endorsed by Kant’s predecessors (including the pre-Critical Kant himself), but is rather a conception of rational psychology that is only possible in light of Kant’s account of the I think as a merely formal representation.

Returning to my initial methodological comments, above, it is in this way that KRP offers a needed corrective to the reading of Kant’s Paralogisms as primarily intended to forestall illicit inferences from his doctrine of apperception. It does this by revealing Kant’s conception of rational psychology as a purely rational discipline to be a significant innovation in its own right, and moreover one that amounts to a radical departure from the antecedent tradition’s approach to the soul. Of course, once Kant has introduced a rational psychology that takes the I think as its “sole text”, it then becomes important for him to show what, if any, cognition of the soul is possible within the strict constraints of such a discipline, and it is in connection with this that he develops a number of his sharpest insights, but this is a task to which Kant can turn only after he has successfully exposed the errors and illusory basis of the distinctive mixed rational discipline of Wolff and his followers.

1.2 The Third Paralogism

Brook reserves his strongest criticism for my account of the Third Paralogism, which concerns the broad topic of the soul’s personality. As I argue in KRP, this notion has been understood rather narrowly by previous commentators in terms of the problem of personal identity. In fact, the tradition of rational psychology, and Kant himself, took this to be only part of what’s at stake in the personality of the soul, as they took it to involve, first and foremost, the soul’s capacity for consciousness of its identity (where this identity is not itself in question). Brook’s criticism does not take issue with my case that this issue is important for an understanding of Kant’s Third Paralogism, though he does call into question some positive claims that I take Kant to make in connection with this general question. In particular, Brook rejects my claim that Kant does allow that the soul, or the ‘I’ that thinks, is a person inasmuch as it is conscious of what is in fact its numerical identity over time.

Before turning to Brook’s objection, though, it might be helpful to consider some of the motivation for my re-reading of the Third Paralogism, in particular, Kant’s striking assertion near the conclusion of the Criticism, where he contends that the transcendental concept of personality “is also necessary and sufficient for practical use” (A365; my emphasis). This assertion, however, is an obstacle for any reading of the Third Paralogism that understands personality solely in terms of personal identity. This is because it would seem to suggest that the identity thought in the bare and decidedly impersonal I think somehow suffices for the attribution of praise and blame, a position which Kant nowhere else asserts and which in any case invites Béatrice Longuenesse’s charge of a paralogism of practical reason.[2] Interpreted, however, as a claim about the personality of the I think, inasmuch as it is (possibly) conscious of the identity of its subject for any manifold of representations (i.e., the transcendental concept of personality), and assuming the practical use of this concept consists in guaranteeing the possibility of this consciousness should the soul survive the death of the body, I argue that Kant can be absolved of the charge of a practical paralogism (cf. KRP, pp. 166–72).

This is to say, however, that Kant allows that the soul, or thinking subject, is in fact a person inasmuch as it is (possibly) conscious of its identity, and specifically conscious of its identity over time, which is what the rational psychologist understands by ‘personality’. Brook claims that, while it is the case that for Kant the representations of all determinate times belong to a single identical self, this falls well short of guaranteeing that the self of which I am conscious in those times is the same throughout—otherwise put, I can at any given time be conscious of a manifold of sensations and memories of past states, but just because these must be taken to belong to the same subject when I (currently) represent them does not mean that I really was the same person through all of those states (as the thought experiment in the footnote at A363–4 makes clear). According to Brook, then, Kant does not (or should not) make such a positive claim about the soul’s consciousness of its own identity in the Third Paralogism.

I agree with Brook that such an inference would be faulty; however, this is not quite the inference I attribute to Kant. Beginning with Kant himself, he does clearly assert in the opening paragraph that we are conscious of the identity of ourselves “in all time” (A362). Yet this claim is immediately qualified, it seems to me, to avoid the very problem identified by Brook. So, instead of claiming that I can be certain that I am the same person now as I was in the recollected states simply in virtue of the identity of the logical subject across those states, Kant’s point is rather that the identity of the subject is the condition for the representation of any specific time (since time is likewise an intuition containing a pure manifold) and, consequently, that there is a sense (albeit not precisely the one intended by the rational psychologist) in which the logical subject is conscious of its identity in whatever time it might represent, that is, “in all time”. Accordingly, to (over-)simplify the difference between the reading Brook targets and my own, Kant’s point has nothing to do with the content of the states involved in the consciousness, but rather purely with their form (the time in which they are represented) and the fact that the identity of the I think is a condition for representing it. Of course, this is not, strictly speaking, a consciousness of the identity of ourselves in time, but rather of the fact that the unity of time as such derives from the unity of the I think, or as Kant suggestively puts it, that “this whole time is in Me”. Even with this distinctive qualification, however, Kant takes it to satisfy the rational psychologist’s general definition of ‘person’ provided in the major of the Third Paralogism: “What is conscious of the numerical identity of its Self in different times is, to that extent, a person” (A361).

As usual, Kant himself bears some of the responsibility for the confusion here as he does not distinguish clearly enough between the kind of identity he’s asserting we are conscious of and the kind of identity he denies we can be conscious of through mere apperception later on in his Criticism. In fact, Kant refers to them both as ‘numerical’ identity; thus, Kant claims in the first paragraph that “I am to be found with numerical identity, in all of this time” (my emphasis) and two paragraphs later, he denies that consciousness of my self proves “at all the numerical identity of my subject” (A363). It is likely by way of resolving this apparent inconsistency that commentators (such as Karl Ameriks) have dismissed the opening paragraphs of the Third Paralogism as Kant speaking in the rational psychologist’s voice (despite the fact that Kant indicates no such thing). Nonetheless, I would claim that both statements can be admitted, provided that the former claim of numerical identity is taken merely as the identity of apperception (‘numerical’ inasmuch as it is that singular consciousness), whereas the latter claim denies numerical identity of the empirical subject, for the reasons that Brook cites, namely, because this likely involves both mental and physical (bodily) criteria of identity. In any case, the point is that I do not think that my account of how the soul or thinking ‘I’ is conscious of its identity in time, and thus a person, commits the mistake Brook correctly takes Kant to warn against.

2. Reply to Marshall

In his comments, Marshall challenges my claim of the innovative character of Wolff’s approach to the soul, contending that there are distinctly Cartesian roots for this alleged innovation on Wolff’s part. So, Marshall contends that precedents can be found in Descartes for Wolff’s use of hypotheses in philosophy, his attempts to found principles on experience, as well as his evident reliance upon experience in his specific treatments of the soul’s faculties, one of his arguments for simplicity, and his account of the union of the soul and body. Lastly, Marshall also suggests that keeping the focus on Descartes, rather than Wolff, is important for understanding Kant’s treatment of the ‘I’, not just for his criticism but also because Kant’s assumption of the reference of the I’ throughout the Critique echoes Descartes’ own usage of it. In addition to thus expanding the current conception of Descartes’ rationalism, Marshall thus hopes to have happened upon, to paraphrase the title of a later treatise by Kant, a discovery in accordance with which any new Wolffian philosophy is supposed to be made dispensable through the older Cartesian one.

Marshall’s challenge is certainly intriguing, and I should say that I share his apprehension in designating Descartes (and Leibniz) as classical rationalists in the way in which that tradition is typically understood. In my conclusion, as Marshall references, I argue that considering Leibniz’s treatments of the soul in light of Wolff’s reveal an otherwise unnoticed empirical foundation for many of his claims about the soul. That the same might be the case for Descartes is something I also considered at one point, though which ultimately I decided not to pursue, partly due to my own laziness (since Descartes, in stark contrast to Wolff, leaves too much unsaid), but partly due to the fact that Kant’s relationship to Descartes is in many respects more complicated than his relationship to Wolff and Leibniz (I will expand on this later).

That said, I will note that it was for just these reasons that I typically avoided ascribing classically rationalistic positions to Descartes throughout the book; so in a quote provided by Marshall I refer to the “rationalistic approach to the soul attributed to Descartes and Leibniz” (KRP, p. 2), and later in the Introduction I similarly refer to the assumption that the only rational psychology at issue in the Paralogisms “is that attributed to Descartes and Leibniz”. Accordingly, since part of the aim of my book was to show that philosophical rationalism has been given short shrift in its limitation to the strain historically identified as classical rationalism, I would be quite happy to allow that Descartes’ rationalism is more supple in the ways in which Marshall outlines, although I do not think this undermines my claim of the innovative character of Wolff’s rational psychology.

Indeed, as Marshall indicates, there is a substantial continuity between Descartes and Wolff, one that has not yet been treated adequately in the secondary literature. Focusing on Wolff’s explicit mentions of Descartes, Wolff offers in his (later) empirical psychology a demonstration of the claim that we exist that is modelled on Descartes’ own argumentative reconstructions of the cogito ergo sum; and Wolff takes Descartes (for reasons we shall see) to undermine any argument for the system of physical influx. These continuities, however, just serve to bring up Marshall’s larger point, namely, that it would appear that Wolff is not really as innovative in his rational psychology as I claim he is.

I do, however, think that there remain important differences between Descartes and Wolff regarding general philosophical methodology and rational psychology in particular. With respect to the use of hypotheses in metaphysics, for Wolff, such use of hypothesis is modelled explicitly on Newton’s treatment (in the Opticks), and its scientific character is evident in Wolff’s primary example of a metaphysical hypothesis, the pre-established harmony, which is the hypothetical ground for the empirically observed agreement between states of the body and the soul but which only remains probable in the absence of empirical confirmation. Wolff’s use of hypothesis within metaphysics strikes me as rather different than Descartes’ use of the hypothesis of doubt which is assumed in advance of metaphysical investigation, and indeed with the aim of generating a body of absolutely certain cognition in which a merely probable Wolffian hypothesis would be rather out of place. The other ‘hypothesis’ which Marshall mentions, in the Discourse, strikes me as of a rather different, rhetorical sort, inasmuch as it is designed to carefully mask the certainty with which Descartes holds the claims (such as that matter consists in extension) that he is presenting as mere suppositions.[3] In any case, even if hypotheses are admitted to play some role in Descartes’ metaphysics, it seems to me that it is a rather different, and less scientific one than that which Wolff assigns to them.

A second point where Marshall claims that Descartes anticipates Wolff is with respect to the relevance of experience to philosophical cognition. Here I think Marshall is quite right to emphasize that Descartes is wrongly represented by Wolff as relying too heavily on the synthetic, demonstrative method (which seems a rather perverse objection for Wolff, of all people to make). Marshall is quite correct to claim that for Wolff, the “indubitable” or “clear” experiences which are taken to validate, for instance, the principle of non-contradiction are not mere sensations but involve reflection on our mental activities, like judging and so forth, which comes close to the role played by “self-perception” in the Meditations and elsewhere. Even so, there is a relevant difference here which I think Marshall overlooks, namely, that Wolffian reflection is explicitly modelled on Locke’s account of reflection or internal sense, and so while it is distinguished from external sensation it is nonetheless a strictly empirical mode of access to the self. Since Descartes does not have access to these Lockean categories, it is, at the very least, not clear that he would accept that all access to the self is strictly empirical, and in fact he does to my mind seem to hold out the possibility of a purely intellectual access to the self (as in our perception of ideas of simple natures, or that we are thinking things) of the sort that Wolff rejects.

Just briefly but relating to this, Marshall mentions Descartes’ reliance upon the senses in his account of the union of the soul and body. In fact, Wolff follows Descartes quite carefully on this point, though he takes unio here to amount to the mere agreement or Übereinstimmung of the states of the body and the states of the soul; that is, what is perceived is just that in sensations or acts of will, states of one body tend to accompany states of the other. What the senses do not disclose, according to Wolff, is the causal ground of this agreement, that is, whether this agreement is accounted for by a direct, physical influence between soul and body, or something else. That experience does not disclose these causal powers is an important anticipation of Hume on Wolff’s part, but in Wolff’s case it leads him to have recourse to a mere hypothesis, namely that of the pre-established harmony, to account for it.

That I have now mentioned Newton, Locke, and Hume in connection with Wolff’s psychology already serves, I think, to mark out its distinctive character. Wolff is aiming in his empirical and rational doctrine of the soul at nothing less than a science in the modern sense, an ambition clearly signalled by his comparison of the use of observation and hypothesis in empirical and rational psychology with their use in astronomy. This leads Wolff to ask questions of the phenomena observed to take place in the soul that Descartes does not bring up, or even dismisses outright. With respect to the faculties, or capacities for sorts of representations, both Wolff and Descartes arguably base their divisions on internal observations of the sorts of representations the soul actually has. Even so, Descartes largely dismisses the scholastic preoccupation with cataloguing the various faculties of the soul and, in the end, only ascribes two faculties to the soul proper, namely intellect and will (cf. Principles I.32—the rest of the faculties are possessed by the soul only in connection with the body). Wolff, by contrast, discovers a bewildering multiplicity of faculties of the soul, and while he similarly reduces them to a single representative power, this is effected only insofar as such a power serves as the requisite causal ground of the empirically-discovered faculties, that is, it amounts to a kind of inference to the best explanation as to the active power that accounts for the soul’s capacity to have various sorts of representations. Such an inference is, of course, part and parcel of the scientific character of Wolff’s rational psychology.

In fact, I think that there is a deeper obstacle to attributing such a properly scientific character to Cartesian pneumatology (for lack of a better name)—given that thinking substance and extended substance are, for Descartes, not just distinct but different, it follows that the methods and principles that apply to the investigation of one sort of substance could not simply be applied to the other. As I write on p. 235,

Wolff does not just break from the pre-modern Scholastic tradition still alive and well in late 18th-century Germany, but also, and significantly, from the modern Cartesian philosophy, the strict dualism of which effectively ruled out any application of the concepts and principles that hold in the investigation of bodies (whether mundane or heavenly) to the soul.

Indeed, Descartes can be taken to make just such a distinction between the ways in which we investigate the soul and that in which we investigate worldly phenomena in his Reply to Gassendi:

You want us, you say, to conduct ‘a kind of chemical investigation’ of the mind, as we would [for instance] of wine. This is indeed worthy of you, O Flesh, and of all those who have only a very confused conception of everything, and so do not know the proper questions to ask about each thing. (AT VII:359–60 [CSM II:248–9])

For Wolff, by contrast, the world is comprised of a single sort of substance, and the parallelism between series of changes in the soul and those of the body suggests to Wolff that the same general scientific laws (for Wolff, even laws of motion applied to thoughts and bodies; cf. Deutsche Metaphysik §737) and concepts (like that of force) hold for phenomena in each domain. This is not to say, of course, that Descartes cannot, in various instances, be interpreted in the way Marshall suggests, and I think the argument for simplicity is a nice example, but for Wolff the use of the tools of modern science to shed light on the essence of the soul was a guiding principle that, as I argue, informed nearly every aspect of his rational psychology.

Does this defence of the distinctive and innovative character of Wolff’s approach to the soul suffice to combat the lazy temptation mentioned by Marshall? Probably not on its own, but there are (at least) two other reasons to seek a better understanding of Wolff, both of which are relevant to precisely the sort of historian who prefers to consider Kant’s thought as a dialogue among the great minds of the tradition. To be brief, the first reason is that, like it or not, Kant seems to have understood Descartes through Wolff’s (or at least a Wolffian) lens—this is suggested, for instance, by Kant’s frequent identification of the syllogistic reconstruction of the cogito ergo sum as Descartes’ proof (see B422–3n. and also Metaphysik Mrongovius, AA 29:877), and by his emphasis in his lectures on metaphysics on the I am as a truth of experience (see KRP, pp. 182–3). Thus, it seems to me that in order to appreciate Kant’s own understanding of his differences from Descartes, we would need to consider Wolff’s influential (if not entirely accurate) interpretation of Descartes.

Second, but related to this, it strikes me that we are well-advised to distinguish Descartes’ rational psychology from that of Wolff because in the end Kant ends up endorsing something rather close to what I take to be the Cartesian conception of mind (while rejecting the bulk of Wolff’s conception). Marshall is right to emphasize the important continuities between Kant and Descartes on their apparently referential use of the I, although it bears noting that in the A-edition at least Kant does not use the phrase ‘I think before the Paralogisms. Yet, like Descartes, Kant emphasizes that the I think, and the concept of the soul based on it, is distinguished from all empirical representations, and that as such it is not the sort of object (or subject) the nature of which can be disclosed by means of the methods of investigation that apply to the external world and of which Wolff is so fond. Indeed, examples abound—like Descartes, Kant emphasizes the primacy of consciousness, the fact that our representations do not resemble their transcendental ground in any respect, and even endorses the qualified Cartesian dualism within appearances. It would seem, then, that it is only by means of understanding the distinctively Wolffian doctrine that Kant is rejecting, that we can appreciate the distinctively Cartesian turn in Kant’s thinking that arguably takes place with the Paralogisms.

3. Reply to Edgar

In his comments, Scott Edgar makes the case for an overlooked, but important Humean contribution to Kant’s argument against the rational psychologist. Edgar notes that Kant’s account of illusion is diagnostic, that is, its primary intention is to account for why the rational psychologist errs in his claims about the soul, and given this, Kant (and his interpreters) owes us an argument for the claim that the rational psychologist is wrong in the first place. Edgar finds a serviceable argument in a passage that I highlight in the opening section of the Paralogisms, where Kant points out that a doctrine which incorporates “observations” of the thinking self could never “serve to teach apodictically about thinking beings in general” (A347). The argument, then, is that the aim of rational psychology to provide universal and necessary cognition of the soul is frustrated by its reliance on experience, which cannot supply such cognition. While Kant might, and likely did, find this argument compelling, however, Edgar points out that it relies on the Humean claim that experience cannot provide warrant for universal or necessary truths. While perhaps philosophically unobjectionable, this nonetheless reveals an important Humean commitment on Kant’s part; yet, since the rational psychologist does not share this commitment, it also seems to take away some of the force of Kant’s argument against their position.

I have to say that I agree with the bulk of Edgar’s comments, and they shed some light on some unnoticed assumptions I myself made in working on KRP. As I present Kant’s account of illusion, its primary aim is to account for how Kant, and others, could have been so mistaken as to take a merely formal unity for a perceived unity, where it is taken for granted that this is an egregious error on the part of the rational psychologist. Moreover, Edgar is likely right that Kant’s reason for regarding this as an error is his acceptance of the claim that the sort of experience the rational psychologist relies upon cannot provide warrant for the sorts of truths that the psychologist is interested in (I will call this ‘the Humean claim’ in what follows). Indeed, while Edgar focuses on how the Humean claim serves for Kant to undermine any relevance of empirical psychology for the rational investigation, it could also be the case that it plays a role in accounting for the change in Kant’s views of the self in the period just before the First Critique inasmuch as he recognised that the necessary identity of the self in all of its representations means that we cannot have access to it by means of experience: as Kant writes at one point in the A-Deduction: “That which should necessarily be represented as numerically identical cannot be thought of as such through empirical data” (A107). Given this, there is good reason to think, as Edgar does, that the Humean claim is an important part of the reason why Kant views the rational psychologist’s project as deeply flawed (and, in turn, why he thought it that much more important to investigate the source of such egregious errors).

I would, however, take issue with a couple of points that Edgar makes: first, I think that the rational psychologist would, to some extent, feel the force of Kant’s argument, and second, and perhaps surprisingly, I think that Kant’s endorsement of the Humean claim that experience cannot provide warrant for universal and necessary truths does not necessarily reveal a strictly empiricistic (or even Humean) commitment at the root of his criticism of the rational psychologist. On the first point, I actually think that the rational psychologists of the Wolffian tradition had been at least dimly aware, or better obscurely conscious, of the sort of tension that Kant would later expose between the warrants supplied by experience and those demanded by a properly rational psychology. As Edgar notes, Wolff introduces the notion of “indubitable experience [ungezweifelte Erfahrung]”, or a kind of cognition which while based in experience can nonetheless be known with certainty to hold universally. An example of this is the claim that, as Wolff puts it, “We are conscious of ourselves and other things”, or the cogitamus, which Wolff claims is known to hold of thinking beings generally inasmuch as “anyone can readily have the same [experience]” and there is nothing that distinguishes my experience in this case from that of others.

While Wolff does not seem to discern any obstacles to such an inference, there seems to be an increasing awareness among his successors that things are not quite so simple. This is particularly clear, for instance, in Georg Friedrich Meier’s important discussion in his Metaphysik, which I discuss in KRP and which Edgar references in his comments. For Meier, as for Baumgarten, rational psychology seeks to show that what has been observed to be the case with respect to myself—that I exist and am a simple substance with a power of representing the world—holds of human souls universally. Following Wolff, Meier contends that I can know that the essence of the human soul in general consists in the power of representing the world because I see in my own case “that this power […] does not constitute a quality particular to me, through which I am distinguished from all other people” but rather that it is something that “all human souls have in common”. As a result, in this case my experience is taken to disclose something that pertains to all souls.

While Meier obviously does not think that deriving such universal claims from experience is impossible, he nonetheless frankly admits that he cannot yet offer the required justification for extending our individual experience of the nature of our own soul to human souls in general:

We can only prove later that the nature and essence of the human soul consists in [the power to represent the world] and we only want to convince ourselves now that this proposition is a universal truth, which can be asserted of all human souls without exception. And, supposing also that we could not prove the universality of this truth [die Allgemeinheit dieser Wahrheit] with the most perfect certainty, then this would no doubt demonstrate that rational psychology is still a deficient science; yet, it would in this respect not be any worse off than other sciences in which one seeks to clarify and prove experiences a priori. (Metaphysik, §735; cf. KRP, p. 49)

The point here, then, is that while Meier does hold out hope that it is possible to draw universal claims from experience, he nonetheless seems to recognise that there is a gap between the singular deliverances of the senses and strictly universal claims that needs to be bridged. It goes without saying, however, that Meier’s fears here are later confirmed and, as Kant will later show, only a rational psychology that draws its concept of the soul from the formal unity of the subject will be able to yield strictly universal and necessary, albeit merely analytic, claims.

Turning briefly to the second point, I would claim that while Kant clearly rejects the rational psychologist’s efforts to draw appropriately universal claims from our direct experience of the self, this does not amount to an obvious endorsement of Hume or indeed of empiricism. So, while Kant, like Hume, denies that actual experience cannot be the source of universal and necessary truths, he nonetheless allows that possible experience can, namely, inasmuch as these truths are principles which can be demonstrated to be required if experience of objects is to be possible in the first place; as Kant writes, experience “has principles of its form which ground it a priori, namely general rules of unity in the synthesis of appearances” (A156/B195). Significantly, the distinction between actual and possible experience is one that Kant later explicitly urges against Hume who had rightly contended that all concepts must relate to experience in order to have objective reality, but nonetheless mistakenly inferred the bankruptcy of the concept of cause because it is not given in actual experience (as an impression) without considering whether it was related to experience as a condition of its possibility. So, Kant writes, Hume did not distinguish between “going beyond the concept of a thing to possible experience” and “the synthesis of the objects of actual experience” (A766/B794).

This would suggest that Kant’s best argument against the rational psychologist does not necessarily reveal the “limits of Kant’s rationalism”, as Edgar claims, at least, not without simultaneously revealing the limits of Kant’s empiricism. Indeed, put somewhat more provocatively, we can see that Kant’s claim that certain transcendental principles can be grounded in the possibility of experience constitutes something of a vindication of the rational psychologist’s claim that experience, suitably construed, can provide a warrant for some universal and necessary truths. In his account of the cogitamus, for instance, Wolff is of course wrong to try, as Kant puts it, to “ground an apodictic and universal judgment on an empirical-seeming proposition” (A346/B404–5). Yet, Wolff is still right to recognise that in the consciousness of ourselves by means of pure apperception, that is, as a condition for the possibility of experience in general, there is nothing specifically individual that is disclosed. In the end, then, I think what makes Kant’s case against the rational psychologist all the more convincing is that it does not show merely that and how the psychologist goes wrong in his consideration of the soul, but also shows in what respect the psychologist, and the Wolffian rationalist more generally, could be taken to have gotten something right.

4. Reply to Kannisto

Kannisto’s thorough and probing discussion of my interpretation and use of Kant’s doctrine of transcendental illusion as it pertains to the soul proceeds on the basis of substantial agreement with positions I endorse and defend in the book, including the nature and relevance of Wolffian rational psychology for Kant’s discussion of the Paralogisms, the interpretative distinction between broad and narrow rationalist psychology, and the importance of reason’s regulative role of the soul and its connection with Kant’s criticism in the Paralogisms. In spite of this common ground, Kannisto raises textual and systematic obstacles to my account of the illusory appearance of the soul, contends that my resulting interpretation of the Paralogisms does not succeed in implicating the narrow rational psychologist in the criticism, and rejects my reading of Kant’s discussion of the regulative role of the pseudo-empirical representation of the soul in the Appendix to the Transcendental Dialectic. I will consider these in turn.

4.1 The appearance of the soul

In KRP, I contend that the illusion that Kant diagnoses at the root of rational psychology consists in the soul seeming to be given in inner experience. That Kant should need to make such an account of illusion the centrepiece of his criticism in the Paralogisms is due to the character of rational psychology that was undoubtedly one of his targets, namely, the rational psychology of the Wolffian tradition which made no bones about its reliance on empirical psychology in the course of elaborating its metaphysics of the soul. Kannisto objects, however, to this account of illusion in terms of the soul (merely) seeming to be given in inner experience, claiming that this account is in tension with (what he takes to be) Kant’s claims that the soul is, in fact, given in experience. In support of his contention, Kannisto cites a number of passages from the B-edition in which Kant explicitly contends that we cognise the ‘I’ as it appears and that “I am also given to myself in intuition” (B155–6) and moreover that it would be wrong to dismiss such a representation as an illusion insofar as one might contend that “my soul only seems to be given” (B69). Indeed, Kannisto goes as far as to identify this subject disclosed in experience as “the empirical soul”, and proceeds to identify it as the subject of “an empirical doctrine of the soul” (cf. A381), which, it is alleged, I cannot easily accommodate in my account of Kant’s psychology.

On the claim that Kant allows an empirical concept of the self, however, it is not clear where Kannisto takes the difference between his view and mine to lie. I do not, for instance, claim that all empirical representations of the self are illusory, and so deny that there is any genuinely empirical cognition of the self. Indeed, not only does Kant defend this in the passages cited by Kannisto from the B-edition (which are connected with the rather obscure doctrine of self-affection), but it is I take it a key plank in Kant’s eventual response to the criticism of the doctrine of the subjectivity of time as it was originally presented in the Inaugural Dissertation. As is well known, Lambert and Mendelssohn had taken this doctrine to amount to the denial of the reality of our cognition of the self, that rendering it as mere appearance made its reality doubtful in the same way that the reality of external things was doubtful. In response, Kant emphasizes the empirical reality of time as it pertains to “the reality of the object of our inner sense”, such that its “reality as [a] representation” remains “immediately clear through consciousness” (A38/B55). In addition, Kant’s acceptance of the fact that there is empirical cognition of the self, that namely “the object of inner sense […] is immediately perceived, and its existence suffers no doubt at all” (A368), also serves as the point of departure for his response to the idealist in the Fourth Paralogism in A.

Perhaps, then, the difference between Kannisto and myself on Kant’s account of the empirical self consists in what we take this self to amount to. This is unlikely, however, since Kant is quite clear on what cannot be given in the manifold of intuition, namely, a “standing and abiding self” (A107), which is to say a representation of the persisting subject of thinking. Inner intuition thus only yields a manifold of our inner states, succeeding one another in time, without disclosing any self whose states these representations are. I take it then, that the “empirical self” for Kant is constituted by the manifold of mental states (sensations, memories, imaginings, and the like) that are disclosed through inner sense, which is to say it is a kind of Humean bundle, and inasmuch as these states are disclosed immediately through intuition, I do not think there is anything illusory about such a self. In fact, cognition of this self, such as the “empirical consciousness of its existence in time” is possible through the application of the concepts of the understanding, although this also presupposes reference to a persisting object of outer intuition, such as the body, as the Refutation of Idealism details.

I take it, then, that when Kant affirms the possibility, and reality, of cognition of the self as it appears, it is to this self as the collection of inner states that he is referring, and indeed when he claims (in contrast with the passages Kannisto cites) that “this I is no more an intuition than it is a concept of an object” (A382), I take it that he is not denying cognition of the self tout court but only of the standing and abiding self as the subject of these states. Thus far, I hope, Kannisto and I agree. I would disagree however with his further claim that this representation of the empirical self can serve as the basis of an “empirical concept of the soul” and indeed the object of an “empirical doctrine of the soul”. First, it is not clear that such a representation of self (as a collection of successive representations of mental states) is appropriately designated a concept of the soul, since the latter would seem to signify in addition the abiding subject of those states which is precisely what is missing in the former. Second, but relatedly, Kant is quite clear that the “systematic unity of all the appearances of inner sense” (A682/B710) is only possible in light of an idea of reason, and one, I would claim, that includes the (illusory) representation of the soul as the persisting object of inner intuition, although I will discuss this in more detail in the final subsection.

4.2 The illusion of the soul

Kannisto next turns to my positive account of the illusion of the soul—that it consists in the subject of thinking seeming to be given as the persisting object of sensible intuition (or, as Kant alternatively puts it, of perception, or of inner experience). In light of Kant’s claim, confirmed above, that nothing persistent is given in inner experience, Kannisto queries: “[H]ow could the soul (even illusorily) seem to be perceived as something persisting in [inner experience]?” Indeed, this is an important question as I think it is key to understanding the development of Kant’s views on rational psychology in the late 1770s. As I document in Chapter 2, Kant himself took the concept that was at the basis of rational psychology to be given in inner intuition at least as late as the period of the Pölitz lecture notes (roughly 1776–78). Thus, the student notes on rational psychology read: “the concept of the soul is a concept of experience” (AA 28:263; cf. KRP, p. 64). Indeed, more than this, Kant at that time took the cognition of the substantiality and simplicity of the soul to be empirically grounded as well. Given that he himself had at one point laid claim to such empirical access to the persisting object of inner intuition, it stands to reason that Kant would have been keen to investigate the source of his error, an error, it so happens, that he shared with the entire Wolffian tradition.

Even so it is important to note that, even after Kant was disabused of the notion that inner sense discloses a persisting self, Kant does not regard it as impossible that such a self is given through inner sense; as he writes, “there is no persistent intuition to be found in inner sense” (B292; my emphasis) rather than that it is inconceivable that such a self be given, and he claims that in our representation of the ‘I’ there is simply no “predicate of intuition that, as persistent, could serve as the correlate for time-determination in inner sense” (B278) rather than that it would be altogether entirely inappropriate to seek for such a predicate (cf. also A350). Since the givenness of the persisting self to inner intuition is not an outright impossibility, but likely only a limitation imposed by our form of inner sense (though this claim would require more elaboration and defence than space here permits), I do not see any obstacle to the possibility that the soul should have the illusory appearance of the persisting object of inner intuition, even if, through the lens of criticism, we can determine that there is no such object really to be found through inner sense.

This account of illusion, while novel and controversial, is supported by largely overlooked textual evidence from both published and unpublished texts (which I present at KRP, pp. 84–90). Kannisto challenges my readings of a couple of these texts (admittedly two of the most compelling ones), but Kannisto’s alternative glosses are hardly the most obvious; for instance, regarding Kant’s claim at A402 that “nothing is more natural and seductive than the illusion of taking the unity in the synthesis of thoughts for a perceived unity in the subject of these thoughts,” Kannisto suggests that this may not mean that “I perceive the unity but that I perceive something that I take to be a unity due to a demand of reason”. It is not clear, however, why the subject of thought should have to be taken as a unity, in accordance with a demand of reason, when Kant is already clear that it contains unity inasmuch as it is (inferred from) the unity of apperception (see, among other texts, A365, A398, A403).

That said, Kannisto is quite right to stress the distinction between the putative perception of the unity (which we do not in fact have) and the demand of reason that we represent the unity of inner appearances (which gives rise to the illusion)—my claim is simply that it is in fulfilling the demand of reason to represent the unconditioned subject of thinking, in the course of which reason infers to the idea of the soul through abstracting the I think from the accompanying empirical manifold, that the idea of the soul naturally seems to represent an empirically given (i.e., perceived), rather than a merely thought unity. Accordingly, the demand on the part of reason, coupled with the fact that the I think is already conditioned by the manifold of sensible intuition, yields the illusory appearance of the resulting idea of the soul as the empirically given, persistent subject of inner intuition.

4.3 Narrow (and broad) rational psychology

This is not, of course, the only evidence I offer in favour of this interpretation of illusion, as I also show how it plays a central role in motivating the specific paralogistic errors on the part of the broad (i.e., empirically-informed) rational psychology of the Wolffian tradition. On this score, Kannisto claims that my account, if anything, is too successful inasmuch as it is no longer clear how this account of illusion applies to the narrow (i.e., strictly) rationalistic psychology of Descartes and Leibniz. As Kannisto writes, such a psychologist seems to be “free from this (allegedly inevitable) illusion, and even avoids […] metaphysical error”. I tackle this problem in the Conclusion, though Kannisto is unsatisfied with my comparatively brief treatment there of this side of the story. I cannot expand much more on this topic here, but it might be helpful to re-emphasize some of the main points of my account.

If we take (as I suggest) the illusion at the ground of Kant’s critique of the rational psychologist (broad and strict) to consist most generally in the temptation to conflate “an empirical perception with an intellectual representation” (p. 231), a conception of illusion which is suggested by the formulation at A402 (quoted above), then I think such an illusion does serve to account for the divergent conflations of the self that lie at the basis of the errors of both sorts of rationalist psychologies. The broad, Wolffian rational psychologist falls prey to this conflation by mistaking what is really an intellectual representation (the soul) for an empirical representation, whereas the narrowly rationalistic psychologist falls prey to the converse temptation and overlooks the (minimally) empirical character of the I think (cf. B422–3n.) and proceeds to mistake it for a purely intellectual representation of an object.

Accordingly, while the two strains of rational psychologists proceed to make rather different sorts of errors (one applying categories in their empirical signification to the soul, the other making a transcendental misuse of the categories with respect to the soul), both can generally be taken to be motivated by an initial confusion between empirical and intellectual representations of the self: either by taking reason’s idea of the soul as an empirical representation, or by taking the “empirical proposition” I think as purely intellectual. Given this, the narrow rational psychologist is not charged with the admittedly incongruent mistake of taking “the soul [to be] given in inner experience”, as Kannisto interprets me, but rather such a psychologist is guilty of overlooking precisely this (minimally) empirical character of the I think in taking what is really an “indeterminate empirical intuition” included in the I think for a purely intellectual intuition.

While I thus take this general account of illusion to account for the errors of both strains of rational psychologist, and in virtue of the same idea of the soul, in the end this only serves to underline the importance of Kant’s criticism of the broad rational psychologist, which goes some way towards vindicating my one-sided focus on it. The fact that the narrow rational psychologist is charged with overlooking the (minimally) empirical character of the I think makes it that much more urgent for Kant to come to grips with the sort of rational psychology that would take this (all-too) seriously. While there are, therefore, two “sides” to the (single) illusion at the root of rational psychology, these are, or so it seems to me, of unequal importance for Kant to address in his criticism.

I should note that Kannisto’s own take on the illusion afflicting the idea of the soul, which he offers as a friendly amendment to my own, faces difficulties of its own (though, in his defence, it is not a fully elaborated position). Very briefly, Kannisto identifies the illusion with the claim that “the soul as the object of the idea exists”, and that the resulting errors on the part of the broad and narrow rational psychologists result from “whether they determine this soul broadly both as an object of experience and reason or narrowly as merely an object of reason”. However, that illusion should be taken to consist in the existence of the soul is a non-starter as Kant is clear that the soul (as the thinking subject, or the ‘I’ of the I think) does exist as when, for instance, he affirms Descartes’ claim that “I (as a thinking being) am” (A368; see also A355 and A342/B400 and KRP 190-1). Accordingly, there is simply no illusion here.

Kannisto goes on to claim that in virtue of falling prey to this illusion the broad rational psychologist is led into error insofar as “the appearance of the soul” that is in fact given in intuition is (mis)taken for, for instance, a substance. Ultimately, however, this fails to make the broad rational psychologist’s error terribly interesting (or sophisticated) after Kant’s exposure of it, since without a (putative) intuition of the persistent to ground its application, the category of substance is simply misused, which error is easily corrected. By contrast, in taking the application of the category as grounded in a tenacious illusory appearance of the soul as the persisting object of inner intuition, we can see why the broad rational psychologist was (and continues to be) misled in making an empirical use of the concept of substance (inasmuch as it seems that its application conditions were fulfilled), and indeed why even psychologists of the calibre of a Wolff, Crusius, and particularly Kant could have committed such an error.

4.4 The empirical concept of the soul and its regulative use

That Kant has an “empirical concept” of the soul is something that Kannisto and I happen to agree on. Indeed, this point has been under-appreciated in the secondary literature, but Kant does refer to a concept of the soul in the Preface to the Metaphysical Foundations of Natural Science that is parallel to the “empirical concept of matter” (cf. AA 4:470). However, where this concept can come from is a matter of dispute between Kannisto and myself. Since Kannisto thinks that the soul “is really given as an appearance”, he takes, I presume, the empirical concept of the soul to be obtained through the usual process of reflection and abstraction.

Yet, once again, given that there is nothing persistent actually given in inner intuition, I am not sure what right Kannisto has to dub the resulting concept the soul since that concept would seem to require a representation of the subject as well, either as the identical I think or as the “standing and abiding” subject, neither of which is available to intuition. Kannisto proceeds to suggest that this concept is a candidate for doing the work which I assign to the illusory idea of the soul in connection with my treatment of the Appendix to the Dialectic, claiming that the availability of an alternative empirical concept suggests the need for a revision to my claim that “only” this idea of the soul “can ground the positive use of the idea of soul”. I see no need for such revision, however, since even granting the entirety of Kannisto’s account, his empirical concept of the soul cannot do the work required of it in the Appendix. As Kant there makes clear, with respect to the regulative use of reason, “a concept of experience (of that which the soul actually is” “cannot lead us very far”, which is what necessitates reason’s activity in framing for itself an idea of the soul in the first place (A682/B710).

The real issue, then, is whether the account of the “empirical concept” of the soul that I defend can in fact do the work it is assigned. On my view, while reason (in accordance with the above) frames for itself an idea of the soul, this idea nonetheless has the illusory appearance of being given as the persistent subject of inner intuition. Accordingly, while this idea, as an idea, is of something that cannot in fact be given in experience (the unconditioned subject of thinking), it nonetheless seems to be, and as a result this idea functions as an empirical (if illusory) concept of the soul. Significantly, while this empirical seeming misleads the rational psychologist in his efforts to cognise the soul, it has a positive function in guiding the understanding in the systematic cognition of inner appearances or the collection of mental states. Kannisto accepts that reason has this positive function, but denies that this idea, in its illusory capacity, can ground it, yet I do not find the objections he raises compelling. Like the focus imaginarius, the idea of the soul is of something that “lies entirely outside the bounds of possible experience”, although I take it that it nonetheless seems to be given in inner experience; and it is quite consistent with the designation of reason’s use as hypothetical in this function, because it is the resulting systematic arrangement of cognitions that is hypothetical or merely problematic, not the underlying idea (A646–7/B674–5).

More importantly, Kannisto overlooks what I take to be the strongest set of evidence in favour of taking such an illusory empirical representation of the soul as the ground of reason’s regulative use. This is the fact that the representation of a persisting subject must serve as the application-condition for the principles of the Analogies and, consequently, the ordering of inner appearances in causal relations (as with their reduction to more fundamental forces). As Kannisto notes, Kant never makes “any explicit references to the soul having to be given specifically in inner experience for the idea to function in its positive regulative role”, yet, the evidence in favour of my view is at least highly dispositive. Indeed, I take my account of the form the illusion must take to follow from the following five claims which are all explicitly asserted by Kant (the longer version can be found at KRP, pp. 217–19):

  1. The idea of the soul plays a positive role in regulating the investigation of inner appearances.
  2. This investigation involves the use of the causal principle of the Second Analogy (cf. A648–9/B677–8), which presupposes something persistent in experience (cf. A188/B231).
  3. This persistent thing cannot be an object of outer sense, without violating the integrity of a properly psychological investigation (A683/B711).
  4. Kant does characterise the idea of the soul in this function as the representation of something persisting (and as a simple substance; cf. A672/B700, A682/B710).
  5. But, the soul cannot be represented as really persisting by means of the senses (A107), and so this representation of something persisting (and so in time) must be effected by reason (A682/B710).

Kannisto’s account of the illusory appearance seems to me to violate (5) and to ignore (2) and (4), which latter oversights are by no means uncommon in the literature. Even so, assuming that we take these claims seriously on Kant’s part, and not as pre-Critical baggage or what not, I think they argue strongly in favour of the account of the illusory appearance of the soul that I provide, namely, as the empirical, albeit illusory, representation on the part of reason of the persistent subject of inner experience.

Lastly, but in connection with this, Kannisto charges me with being so “fixated” on the empirical character of the representation of the soul to the extent that I overlook Kant’s real interests in undermining the possibility of a priori cognition of the soul, whether or not that concept is ultimately derived from experience or not. Indeed, I do take Kant’s (thus far unnoticed) shift from the claim that the concept of the soul is reflected from experience (in the Pölitz notes most obviously) to his identification of it as an inferred concept of reason in the Critique of Pure Reason, to signal a significant change in his approach to rational psychology (cf. KRP, pp. 72–81).

However, I think Kannisto is guilty of an anachronism here in what he understands by the “a priori knowledge of the soul” I am alleged to be leaving out. After Kant, of course, such knowledge is understood as what can be (putatively) cognised of the formal I think independently of all experience, and Kant rightly stresses in the Paralogisms, consistent with his discussion in the Transcendental Analytic, that such cognition is impossible. Before Kant, however, a priori cognition of the soul was understood merely in terms of what can be known of the soul through inferences from the concepts and principles disclosed in empirical psychology (cf. KRP, pp. 39–40). Accordingly, while the account of the empirical origin (or otherwise) of the representation of the soul is arguably irrelevant to the former conception of a priori cognition of the soul, it is entirely relevant to the latter since if, as Kant came to think, the soul is not an object of experience at all but an artifact of reason, then it is wrongheaded to think that rational psychology is ultimately continuous with empirical psychology, as Kant shows. As I argue, this is a radical claim on Kant’s part, although its radical character is not evident so long as commentators continue to conflate the mixed rational psychology that is the primary target of Kant’s criticism in the Paralogisms with that pure rational psychology that is only conceivable when we take the formal, and eminently Critical, I think as its “sole text”.

This only reconfirms, I think, that a full appreciation of the change(s) effected by Kant’s Copernican Revolution requires a thorough understanding of the regime it deposed. Kant scholars in the Anglo-American tradition have come a long way since Jonathan Bennett’s boast that no interpretative harm would come from ignoring “Wolff’s yard-long shelf of philosophy”,[4] and have come to recognize the indispensability of Wolff’s thought, not to mention that of Baumgarten, Crusius, Knutzen, Meier, Lambert, and Tetens, for an understanding and appreciation of the many insights of Kant’s philosophy. I hope to have provided further proof of the relevance of this tradition in Kant and Rational Psychology and, further, to have shown that the eighteenth century German philosophical tradition is even interesting in its own right. In closing, I would like to thank all of my critics for a very thoughtful and engaging discussion of my Kant and Rational Psychology. It is always a pleasure and privilege to discuss one’s work, but it is especially so with such knowledgeable, challenging, and charitable interlocutors.


[1] So, Ameriks claims that “it would be an astounding objection [on Kant’s part] to point out that such a characterization does not give us an empirical specification of the self—since the whole point of such [rational] psychology is to make non-empirical claims” (K. Ameriks, Kant’s Theory of Mind, 2nd edition [Oxford UP, 2000], p. xxviii).

[2] See B. Longuenesse, ‘Kant on the Identity of Persons’, Proceedings of the Aristotelian Society 107 (2007): 149–67; cf. p. 161.

[3] It bears noting, however, that some suspect that Wolff’s designation of the pre-established harmony as a mere ‘hypothesis’ is intended in this ‘Copernican’ sense as well, that is, as masking his confidence to avoid censure by a powerful Pietist opposition.

[4] J. Bennett, Kant’s Dialectic (Cambridge UP, 1974), p. 6.

© Corey W. Dyck, 2015.

Corey Dyck obtained his Ph.D. in Philosophy from Boston College in 2006, and is Associate Professor of Philosophy at the University of Western Ontario, Canada. He specializes in the history of German philosophy, with an emphasis on the eighteenth century. Besides contributions to volumes, he has published articles in the journals Journal of the History of PhilosophyKant-StudienBritish Journal for the History of PhilosophyPhilosophy CompassKantian Review, and Kant Yearbook. He is also the co-translator of Moses Mendelssohn’s Morning Hours: Lectures on God’s Existence (Springer, 2011), and, together with Falk Wunderlich, editor of Kant and his German Contemporaries (Cambridge UP, forthcoming).