Kant’s objections to Cartesian accounts of the mind in the first Critique often lead readers to assume that he endorses some form of materialism, but the discussion of psychological ideas serves, Kant claims, to “destroy completely all materialistic explanations of the inner appearance of our soul” (4:334). As the chapter shows, the Prolegomena makes a distinctive appeal to the regulative use of these psychological ideas to argue against psychological materialism, or the view that our psychological states can be explained in terms of materialistic grounds, and further buttresses – in a different fashion – the position that Kant develops in the ‘Paralogisms’ section of the first Critique.

Chapter 3, “The Form of Reflexivity and the Expression of Self-Presence”, explores the role of transcendental apperception for inner experience according to the Transcendental Deduction (B) of the first Critique. By showing the insufficiencies of two alternative views defended in the literature, namely the psychological view and the logical view, the chapter argues that transcendental apperception is the capacity for reflexive consciousness in general. Its characteristic form, the general form of reflexivity, is the most general condition on any conscious representation and can be expressed by the phrase “I think”. The chapter concludes by arguing that the phrase “I think”, if in fact attached to a representation in thought, expresses self-reference to oneself as individual thinker, yet without determining oneself.

Chapter 6, “The Demands of Theoretical Reason and Self-Knowledge”, completes Kant’s account of empirical self-knowledge – the theoretical knowledge I have of myself as a psychological person. Following Kant’s general theory of knowledge, I argue that self-knowledge requires – in addition to a cognition of myself – an attitude of assent towards this cognition and an epistemic ground for holding this cognition to be true. By laying out different types of epistemic grounds, I distinguish corresponding levels of self-knowledge. The highest level is a complete comprehension of myself based on an a priori idea of myself as a whole. While this highest level can never be attained, it sets the normative standard for all lower levels of self-knowledge. Hence, we are bound to conceptualize all psychological phenomena in accordance with a system of psychological predicates, and to approximate a complete individual self-concept, which, if available, would completely a+H9nd fully adequately describe an individual person. Finally, I outline possibilities of error, such as self-blindness and self-deceit, and revaluate the doctrine of transparency that is often ascribed to Kant.

Chapter 4, “The Conditions of Self-Reference”, examines two ways in which one can conceptually represent oneself in judgements, in light of the results of the Paralogisms (in the Transcendental Dialectic of the first Critique). The logical “I” defines the way in which any thinking subject must represent itself in thought, and hence its logical predicates are conditions of I-judgements in general. The psychological “I” is used to represent oneself in empirical I-judgements, viz. inner experience, and under the temporal conditions of perception (which were derived in Chapter 2). Yet a close reading of the Paralogism of Personal Identity, and other passages, reveals that the principle of persistence cannot be applied in inner experience. The category of substance, therefore, requires a different kind of sensible explication to capture the trans-temporal unity of persons.

As the pre-eminent Enlightenment philosopher, Immanuel Kant is famous for emphasizing that each and every one of us is called to “make use of one’s own understanding without direction from another” (Enlightenment 8:35). We are all called to make up our own minds, independently from the external constraints imposed on us by others. In the face of this Enlightenment calling, much of Kant’s philosophy, then, reads as a manual for how to employ one’s mental faculties in the proper way – faculties that are supposed to be universally realized by all human beings. Given his focus on a universal conception of the human mind, Kant tells us surprisingly little about what makes us the unique individual persons we are and how we come to know ourselves as such.

Chapter 1, “Inner Sense as the Faculty for Inner Receptivity”, sets the stage by introducing Kant’s basic model of representation and by defining two pairs of concepts that will guide my analysis: reflexivity and referentiality, on the one hand, and objective and subjective validity on the other. Through an examination of the historical context, the chapter develops an account of inner sense as a transcendental faculty of sensibility, and gives preliminary accounts of central concepts, including affection, sensation, appearance, intuition, perception, and experience. As a result, the chapter suggests that – by analogy with outer sense – inner sense receives inner appearances and yields distinctively inner intuition according to its specific form, i.e., time. The full argument for this claim will be put forward only in Chapter 2. Finally, by considering insights concerning the faculties for desire and feeling from the third Critique and the Anthropology, the chapter develops a broader notion of inner receptivity as susceptibility to all mind-internal causes.

This book set out to explore what, for Kant, makes us unique individual persons and how we come to know ourselves as such. It has done so by examining levels of representational self-determination and by showing how the bits and pieces of a mental life constitute a unified person. Beginning with the lowest levels of self-affection and inner perception (Chapter 2), it moved to the levels of self-consciousness (Chapter 3), logical self-determination (Chapter 4), and inner experience (Chapter 5), and, finally, arrived at the normative demands that govern both the acquisition of self-knowledge (Chapter 6) and the self-formation as a unified person (Chapter 7). These normative demands are based on the idea of the soul, which has been shown to define the unifying form of a person’s mental life. It is the idea under which we have to conceive of ourselves as persons and the idea that prescribes what it takes to be a person at all.