Kant's Transition Project and Late Philosophy is the first study to provide a close reading of the connection between texts written by Kant during 1796 and 1798. Connecting Kant's unfinished book project, the Opus postumum, with the Metaphysics of Morals, it identifies and clarifies issues at the forefront of Kant's focus towards the end of his life. Labelled by Kant as the “Transition Project”, the Opus postumum generates debate among commentators as to why Kant describes the project as filling a “gap” within his system of critical philosophy. This study argues for a pervasive transition project that can be traced through Kant's entire critical philosophy and is the key to addressing current debates in the scholarship. By showing that there is not only a Transition Project in Kant's theoretical philosophy but also a Transition Project in his practical philosophy, it reveals why an accurate assessment of Kant's critical philosophy requires a new understanding of the Opus postumum and Kant's parallel late writings on practical philosophy. Rather than seeing Kant's late thoughts on a Transition as afterthoughts, they must be seen at the centre of his critical philosophy.