The notion of system in Kant’s conception of a priori forms of knowledge is an organological one. Central to a philosophical system of this kind is the unity of purpose. Epistemological activity of transcendental subjectivity is therefore focussed self-organized activity with the judgement of experience as its telos.The present study mobilizes this basic insight to interpret the essential elements of the transcendental constitution of knowledge, i.e. of pure forms of intuition and categories. In this forced understanding, experience is living self-execution of the subject responsible in its theoretical empirical verdicts.Ultimately, this activity must even be interpreted as praxis in the moral-practical sense. These results extrapolate theses which at times are concealed in Kant’s work and sometimes are even counter-cast, so that occasionally one has to use Kant to argue against Kant.They also reveal aspects which have not been thematized in the conventional reception of Kant or have hitherto been missed in his work.