In this book, Dennis Schulting presents a staunch defence of Kant's radical subjectivism about the possibility of knowledge. This defence is mounted by means of a comprehensive analysis of what is arguably the centrepiece of Kant's Critique of Pure Reason, namely, the Transcendental Deduction of the Categories. Radical subjectivism about the possibility of knowledge is to be understood as the thesis that the possibility of knowledge of objects essentially and wholly depends on subjective functions of thought, or the capacity to judge by virtue of transcendental apperception, given sensory input. Subjectivism thus defined is not about merely the necessary conditions of knowledge, but nor is it claimed that it grounds the very existence of things. Novel interpretations are provided of such central themes as the objective unity of apperception, the threefold synthesis, judgement, truth and objective validity, spontaneity in judgement, figurative synthesis and spatialunity, nonconceptual content, idealism and the thing in itself, and material synthesis. One chapter is dedicated to the interpretation of the Deduction by Kant's most prominent successor, G.W.F. Hegel, and throughout Schulting critically engages with the work of contemporary readers of Kant such as Lucy Allais, Robert Hanna, John McDowell, Robert Pippin, and James Van Cleve.