Die Seele und ihre Vermögen: Kants Metaphysik des Mentalen in der Kritik der reinen Vernunft
Kant’s Critique of Pure Reason aims to determine boundaries of reason. Reason is a
faculty of the soul. But Kant does not deal explicitly with the question what a faculty of the soul itself may be. The dissertation construes Kant’s implicit notion of a mental faculty in relation to psychological debates in 17th and 18th century Germany. It can be shown that Kant agreed with Christian August Crusius in that faculties are real properties, an assumption that was denied by Christian Wolff. This poses a problem which is fundamental for understanding Kant’s project: How can we have knowledge of mental faculties at all? If knowledge of faculties was empirical for Kant, it would belong to psychology rather than to epistemology which, according to Kant, must not rely on empirical facts. In order to find out whether there can be knowledge a priori about mental faculties, the book provides a close reading of relevant passages from published texts and other sources (lecture transcripts, Reflexionen). The final result is negative: Kant has no conclusive argument for the real existence of mental faculties. Nevertheless, an awareness of Kant’s unwritten “metaphysics of the mental” is essential for understanding implicit premisses of Kant’s thought.