My aim is to reconstruct the basic steps and the fundamental idea of Kant’s transcendental deduction of categories as well as Hegel’s interpretation and reframing of Kant’s idea. Hegel’s reading is crucial for two reasons: first, for fixing the basic form of the Kant­ian argument and secondly, for understanding its metaphilosophical relevance. For Hegel, philosophical proof has a specific nature, which distinguishes it from scientific proof and brings it closer to a juridical one. In this perspective the transcendental deduction, which (...) is universally considered one of the most difficult chapters in the history of philosophy, reveals itself as the genuine clarification of specifically philosophical proof. I first present the idea of Kant’s transcendental deduction in the Critique of Pure Reason as well as its Hegelian reading in the Science of Logic and reformulation as the very method of philosophy in the Philo­sophy of Right. I show what in the Kantian argumentation constituted the basis for Hegel’s own interpretation and transformation. In so doing, I highlight a ‘red thread’ between the two ideas of the transcendental deduction. I conclude by proposing a formal account of Kant’s and Hegel’s ideas and by summing up the main metaphilosophical insights we can gain from Kant’s idea and its Hegelian interpretation. (shrink)