The literature of modernism around 1900 reflects an iconic change in the relationship between the prevailing cultural medium of writing and the rival pictorial medium. Challenged by the heightening of evidentiality promised by avant-garde painting, early cinema, and linguistic and psychological imagery, authors like Hofmannsthal, Rilke, and Musil developed a language of visionary boundary-transgression that remained fully aware of its resources while at the same time appropriating the other medium for its expressive purposes. The study inquires into the poetological consequences of the specific pictorial awareness of modernist literature and relates the contexts in which it developed to the history of knowledge.