Abstract

The ArgumentIn this essay I will sketch a few instances of how, and a few forms in which, the “invisible” became an epistemic category in the development of the life sciences from the seventeenth century through the end of the nineteenth century. In contrast to most of the other papers in this issue, I do not so much focus on the visualization of various little entities, and the tools and contexts in which a visual representation of these things was realized. I will be more concerned with the basic problem of introducing entities or structures that cannot be seen, as elements of an explanatory strategy. I will try to review the ways in which the invisibility of such entities moved from the unproblematic status of just being too small to be accessible to the naked or even the armed eye, to the problematic status of being invisible in principle and yet being indispensable within a given explanatory framework. The epistemological concern of the paper is thus to sketch the historical process of how the “unseen” became a problem in the modern life sciences. The coming into being of the invisible as a space full of paradoxes is itself the product of a historical development that still awaits proper reconstruction.