The fourth moment of the Analytic of the Beautiful is concerned with the modality of a pure judgment of taste, specifically the necessity claim or demand for agreement that is made in connection with a judgment purporting to be pure. It was argued in Chapter 3 that the modality of the pure judgment of taste, like that of logical judgments, is unique among the moments in that it does not contribute anything to the content of the judgment, but concerns instead its bearing on the judgment of others, or what might be termed its evaluative force. Thus, the content of a pure judgment of taste is completely determined by its disinterestedness, its subjective universality based on a free harmony of the faculties, and its basis in the form of the object or its representation. Since these exhaust the conditions under which a given judgment of taste can be pure, they also determine the distinct elements of the quid facti. What the fourth moment analyzes is the demand for the agreement of others made by a judgment possessing these features.

Its basic claim is that this demand presupposes the idea of a common sense [Gemeinsinn], an idea which combines within itself all of the factors analyzed separately in the first three moments, and which therefore functions as the supreme condition of the possibility of a pure judgment of taste.