Abstract

The aim of this paper is to examine Francis Glisson’s theory of perception insofar as it concerns the lowest class of living beings: plants. Plants have a special status, they are located between inanimate objects and animals in the hierarchy of being. Unlike the former, they are organic, but unlike the latter they are unconscious. Peculiar to Glisson is the claim that vegetative organization requires self-referential perception. In light of traditional epistemology, this claim may sound puzzling, because we tend to associate self-representation with conscious thought. In order to make sense of Glisson’s self-referential, but unconscious perceptions, the first part of the paper investigates the role of perception in the vegetative process of organization. The second part is a comparative study on two ways of drawing the distinction between unconscious perceptions and conscious sensations. The first one is the Cartesian approach as outlined by Antoine Arnauld in the early 1680s, the second one is Glisson’s theory. In light of the comparison it is argued that Glisson’s is a higher order theory of sensation in which the phenomenon of consciousness requires the delimitation of the all-inclusive, self-referential nature of perception.