In upholding the sensory principle of the classification of art, La Fontaine, consciously or not, took account of a tradition beginning in antiquity. The “philosophical century” was to have introduced a conceptual criterion, that of time and space. James Harris and Lessing are among the most ardent proponents of the division of art into the spatial and temporal. This criterion has played an important role in aesthetics. Among the countless systems of art classification developed in the course of the last two centuries, it has held a place of prominence to this day. Even those theorists who seek to soften the opposition between music and literature on the one hand, and the plastic arts on the other (Oskar Walzel), and who stress the union of space and time in the perception of the aesthetic object (Mikel Dufrenne), do not abandon the fundamental distinction between temporal and spatial art.