Induction of visibility: reflections on histological slides, drawing visual hypotheses and aesthetic-epistemic...

This paper focuses on histological slides and on the strategies of visual transformation of Santiago Ramón y Cajal. His practices and concepts reveal that not only the slides as such and their images have cognitive and aesthetic values crucial to the epistemic gain about the original material, but also the processes that unveil and reassess these values during observation and imaging. Therefore, considering the nature of these processes contributes to--besides the inquiry about the slides themselves--disclosing their role as epistemic and cultural objects in the history of the life sciences. To be beneficial to this inquiry, however, a closer definition of these processes is needed. I propose to define these operations in terms of the notion of "induction of visibility," which specifies general concepts of "visualisation" or "making something visible" as an instrument generating and transporting visual knowledge. Processes of visibility induction, I argue, constitute a category of visual action in their own right, which derives from and generates aesthetic and epistemic operations likewise. For this category, I propose, therefore, the concept of "aesthetic-epistemic action".