 With respect to the ostensibly subjective side of human knowing, he invested considerable energy in articulating a concept of “perception of relations” (perception des rapports) which functions both as a theory of judgment (explaining why it is that we find certain kinds of symmetry and proportion pleasing) and a theory of cognitive functioning at a more basic level, one characterized by psychoneural relations, as it were. Countering that subjective emphasis, however, Diderot also warned against the “surfeit” of organic sensitivity as a source of hyper-reactivity, and of sensory stimulus as a ground for perception without any internal unifying principle. These reflections are also found in the character Bordeu in the Rêve who serves to ground the perceptions and queries from Mlle de Lespinasse regarding the ravings of the dreaming D’Alembert in a clear objective ground. Diderot describes the overly sensitive actor in the Paradoxe sur le comédien as suffering from a “weakness in their constitution”, and speaks ironically about the welter of emotions (“des sensibilités diverses”) on stage being incapable of forming a unified whole.