Précis of <i>The World According to Kant―Appearances and Things in Themselves in Critical Idealism</i>, Oxford/New York: Oxford University Press, 2021

Throughout the history of the reception of his philosophy, Kant has often been read as a thoroughly anti-metaphysical thinker. According to this kind of reading, he is squarely focused on, and his positive contributions in theoretical philosophy are confined to, epistemology, whereas his contributions to metaphysics are merely negative, consisting in a scathing critique. Despite its popularity, this anti-metaphysical reading has not gone unchallenged, however. There have been several periods since the early nineteenth century in which metaphysics-friendly readings have flourished. Surveying contemporary Kant scholarship, it is becoming harder and harder to deny that one of these periods is right now. I count myself among the dissenters from the anti-metaphysical paradigm. As I read him, Kant is not opposed to metaphysics per se but merely to the method that metaphysicians have employed before him. As far as the cognition of freedom, God, and immortality is concerned, which is metaphysics’ ‘final aim,’ Kant's methodological correction is to argue that this cognition is possible only ‘in a practical respect,’ that is, by relying on substantive premises that can be justified only in the context of his practical philosophy, based on considerations about the conditions for the possibility of rational agency. But his theoretical philosophy also contains quite a bit of metaphysics, which supplies the basic framework in which his practical philosophy is developed and without which it could not even get off the ground. The metaphysical content of Kant's theoretical philosophy is his critical idealism, understood as an ontological position. His methodological innovation in the theoretical context consists in relying on broadly epistemological considerations about the nature and function of human cognitive faculties in order to derive ontological conclusion about the nature and ontological status of various kinds of entities. In The World According to Kant, I offer an interpretation of Kant's critical idealism understood as an ontological position, provide a detailed analysis of his arguments for it, and identify the fundamental assumptions on which it depends. (Kant's epistemology and philosophy of mind are the topic of a companion volume currently in progress.) While the primary goal of this exercise was to furnish a faithful reconstruction of Kant's account of the world, I hope that my efforts at clearly presenting it in all of its intriguing glory will also help to generate interest in it as a viable contender in the ongoing debate about the fundamental structure of reality. I, for one, find it rather attractive and believe that it merits our serious consideration. After the dust has settled, the world according to Kant can be described as follows. Its most striking feature is that it comprises several distinct levels of reality, which differ in fundamentality. This is a feature of the world about which Kant agrees with Leibniz. In Kant's case, there are at least two such levels, which I call the ‘transcendental level’ and the ‘empirical level.’ The transcendental level, which is the most fundamental level, is a mind-independent level at which things in themselves exist. The empirical level is a mind-dependent level at which Kantian appearances and empirical space and time exist. Although Kant does not explicitly talk about it, it is useful, again following Leibniz, to add a second, even less fundamental mind-dependent level, which we may call ‘fictional level,’ at which imaginary entities such as fictional characters, mathematical objects, and pure space and time exist. Appearances and imaginary entities are intentional objects understood as immanent representational contents, or ‘in-existent’ objects of representations. The intentional object of a representation is distinct from the representation itself, that is, the vehicle of the content, which is a property of an individual mind; in the case of referring representations, the intentional object may also be distinct from the referent of the representation, and certainly is distinct from it if the referent is mind-independent. Appearances and other intentional objects are fully mind-dependent in the sense that they have being and all of their determinations (that is, roughly, their real properties) and other ontological ingredients (if there are any) solely in virtue of being represented by finite minds. In contrast to appearances, things in themselves are fully mind-independent in the sense that they neither exist nor have any of their determinations or other ontological ingredients in virtue of being represented by finite minds. Appearances and other intentional objects are mind-dependent through and through, while things in themselves are mind-independent through and through, so to speak. Due to their radically different nature, things in themselves and appearances are numerically distinct and do not ontologically overlap in any way. Even though, just like imaginary entities, appearances are fully mind-dependent, they are ontologically more fundamental thanks to the special kind of representations on which they depend. Appearances are intentional objects of experience, whose explication is Kant's main focus in the Analytic of the Critique of Pure Reason (‘Critique’ from now on). Outer appearances are intentional objects of outer experience; inner appearances are intentional objects of inner experience. The nature of the mind-dependence of appearances and Kant's account of experience are examined in chapter two. Two defining theses of Kant's critical idealism are the claims that empirical objects such as tables and planets are outer appearances and thus fully mind-dependent, and that empirical selves or minds, that is, the minds familiar to us from our self-consciousness, are inner appearances and thus fully mind-dependent. Another defining thesis of Kant's critical idealism is the claim that pure space and time are forms of sensibility, one of our two main cognitive faculties. That pure space and time are forms of sensibility properly understood entails that they are intentional objects of pure intuitions, the a priori representations produced by sensibility. Pure space and time are thus fully mind-dependent. Since Kant conceives of empirical space and time in relationalist terms as constituted by the spatial and temporal determinations of empirical objects, which are fully mind-dependent, he is committed to the view that empirical space and time are fully mind-dependent too. Kant is thus a genuine idealist about empirical objects, empirical selves, and (empirical and pure) space and time. Empirical objects, empirical selves, and (empirical and pure) space and time are transcendentally ideal, that is, they are ideal or fully mind-dependent with regard to the transcendental, most fundamental level of reality. The part of Kant's critical idealism captured in these claims is his transcendental idealism. Empirical objects, empirical selves, and empirical space and time exist at, and are mind-independent with respect to, the empirical level of reality. For these entities are represented in experience as existent and mind-independent, which means that, with respect to the empirical level, or empirically speaking, they exist and are mind-independent. They thus are empirically real, that is, they are real with regard to the empirical level of reality. But, in contrast to other intentional objects, appearances genuinely exist, that is, they do not only exist at their special level of reality or in their special ‘intentional world,’ but even from (what I call) the point of view of fundamental ontology. The more fundamental ontological status of appearances compared to other intentional objects is due to the special character of experience. Experience both conforms to certain formal conditions of objectivity that distinguish it from other kinds of representations such as dreams and hallucinations, and depends on the affection of sensibility by things in themselves, which function as ultimate material conditions of experience and thereby ground appearances, supplying them with extra ontological weight, so to speak. The empirical level, despite being a mind-dependent level of reality, is home to genuinely existing entities. Kant's empirical realism about empirical objects, empirical selves, and empirical space and time, is thus a genuine kind of realism. That Kant's critical idealism includes empirical realism is also what distinguishes it from the idealism of Berkeley. Like Kant, Berkeley is a genuine idealist about empirical objects but (on Kant's reading of him) lacks the resources to introduce a further distinction between intentional objects that genuinely exist and intentional objects that only pseudo-exist. In contrast to Kant, Berkley is both a transcendental and an empirical idealist. The defining theses of Kant's transcendental idealism and empirical realism are collected and explicated in chapter three, which also comprises an examination of the relation between pure and empirical space and time, and a sketch of the differences between Kant's and Berkeley's idealism. Despite their numerical distinctness, appearances and things in themselves are closely related. Things in themselves ground appearances by transcendentally affecting sensibility and thereby bringing about sensations, which, in the construction of experience, provide the ‘matter’ for appearances and underwrite their existence. Empirical objects are grounded in things in themselves that are distinct from human minds. The grounding relation in this case need not be one-to-one. By contrast, each empirical self is grounded in a unique thing in itself, the transcendental self, which is a human transcendental mind. Each human being is thus composed of multiple distinct parts that differ with respect to their basic ontological status, namely, an empirical self and a body, both of which are appearances, a transcendental self, which is a thing in itself, and possibly some additional things in themselves that ground the body. The relation between appearances and things in themselves, the differences between Kant's and Berkeley's views about the grounding of empirical objects, and Kant's multiple-parts account of the human being are discussed in the first part of chapter five. In addition to affecting sensibility, things in themselves are supersensible, non-spatial and non-temporal, as well as distinct from God and thus finite. They also genuinely exist. Kant is a realist about things in themselves, as opposed to a fictionalist as which he is often portrayed. Last but not least, things in themselves as understood by Kant must be sharply distinguished from things in themselves as understood by the Leibniz-Wolffians. In contrast to Kantian things in themselves, Leibniz-Wolffian things in themselves are noumena, that is, objects that can be cognized in terms of pure concepts alone. The fictionalist reading is critically analyzed in chapter six, which also contains an examination and explanation of Kant's seemingly favorable attitude towards the Leibniz-Wolffian conception of things in themselves. As far as Kant's fundamental assumptions are concerned, the ultimate basis for his arguments for critical idealism is the finitude of the human mind and, more specifically, its fundamentally uncreative nature in which this finitude manifests itself. That the human mind is uncreative brings with it, among other things, that it necessarily includes a passive component, sensibility, which produces representations only in response to being affected. Being fully active and able to produce not only formal but also materially contentful representations on its own power is the prerogative of an infinite, divine mind. The essentially passive nature of sensibility underwrites the main premises in Kant's master argument for his transcendental idealism in the Transcendental Aesthetic of the Critique and in his arguments for the existence of things in themselves. Kant's case for transcendental idealism, including the master argument, is presented in chapter four; Kant's arguments for the existence of things in themselves are reconstructed in the second part of chapter five.