The habit of separating the intuitive from the abstractive functions, as they were called in the Middle Ages, goes far back in our tradition. Descartes, in the sixth Meditation, defined man as "a thing that thinks," to which reasoning came naturally; whereas imagining, the activity of the senses, required a special effort and was in no way necessary to the human nature or essence. The passive ability to receive images of sensory things, said Descartes, would be useless if there did (...) not exist in the mind a further and higher active faculty capable of shaping these images and of correcting the errors that derive from sensory experience. A century later Leibnitz spoke of two levels of clear cognition.1 Reasoning was cognition of the higher degree: it was distinct, that is, it could analyze things into their components. Sensory experience, on the other hand, was cognition of the lower order: it also could be clear but it was confused, in the original Latin sense of the term; that is, all elements fused and mingled together in an indivisible whole. Thus artists, who rely on this inferior faculty, are good judges of works of art but when asked what is wrong with a particular piece that displeases them can only reply that it lacks nescio quid, a certain "I don't know what." · 1. Leibnitz, Nouveaux essais sur l'entendement humain , bk. 2, chap. 29. Rudolf Arnheim is the author of Art and Visual Perception: A Psychology of the Creative Eye, Toward a Psychology of Art, The Dynamics of Architectural Form, and Visual Thinking. His previous contributions to Critical Inquiry are "On the Nature of Photography" and "A Stricture on Space and Time". (shrink)