Abstract

In the Western tradition of thinking, the tradition of Plato and Descartes, the separation between the human intellectual faculties and the sensuous faculties has influenced everyday thinking about perception. Human cognition, the capacity of reason and critical thinking, has always been privileged over the sense impressions. In Platonist ontology, the world of appearances is separated from the world of ideas and, consequently, what is observed and perceived is at peril of being deceptive. Therefore, one must not put too much emphasis on what is seen; only critical reflection based on systematic doubt is to be trusted. In addition, until at least the mid-nineteenth century, Crary (1990) argues, human visual perception was rendered unproblematic as it was conceived of as a mere registration of external events. The camera obscura, a device known since at least the medieval period, served as a model for human visual perception. In the mid-eighteenth century, however, both philosophers, such as Arthur Schopenhauer, and scientists, such as the German scientist Herman von Helmholtz, started to theorize on human visual perception. They began to conceive of human vision as a form of trained capacity and a matter of attention rather than a passive registering of the external world. Instead of being a universally shared human capacity, vision was portrayed as a subjective and highly personal skill bound up with other cognitive and perceptual systems. For instance, the ability to concentrate the gaze for longer periods of time was found to be a matter of training and personal interest and not an inherent capacity.