If discourse on visuality in the seventeenth and eighteenth centuries repressed and concealed whatever threatened the transparence of the optical system, Goethe signals a reversal, and instead poses the opacity of the observer as a necessary condition for the appearance of phenomena. Perception occurs within the realm of what Goethe called “das Trübe” – the turbid, cloudy, or gloomy. Pure light and pure transparence are now beyond the limits of human visibility.
–Jonathan Crary, Techniques of The Observer
The site of analysis is no longer representation but man in his finitude. . . . It was found that knowledge has anatomo-physiological conditions, that it is formed gradually within the structures of the body, that it may have a privileged place within it, but that its forms cannot be dissociated from its peculiar functioning; in short, that there is a nature of human knowledge that determines its forms and that at the same time can be manifest to it in its own empirical contents.
–Michel Foucault, The Order of Things