Interpretations of Kant’s Critique of Judgement often focus on the problematic of beauty and taste which a large part of the first part of his book is devoted to, or on questions of teleology connected with living nature analysed in the context of the second part. This article attempts to show that Kant in the third Critique tries to include the question of the relation of the theoretical and practical sphere in his treatment of this problematic. The crystallisation of Kant’s thought in this respect began to take place from the First Critique onwards. In clarifying this question we put to use the central concept of the Third Critique – purposefulness. The development of this concept in Kant’s thinking is traced. In the concluding part of the study we attempt to show that in employing the newly-formulated conception of purposefulness, Kant tackles the question of how the two spheres are connected by means of a thesis concerning the unity of the super-sensory substrate of nature and freedom.