In this talk I will present material from my current book project, Writing the Rules of Reason: The Social Life of Notation from Logic to Computing. It is a history of two fundamental transformations in the study of logic: First, logic was reconstructed from a humanistic study of reason to a mathematical science. Second, this new mathematical science was taken as a theoretical foundation for digital computing. I tell these intertwined stories by focusing on writing. How exactly does one write down an abstract logical statement? Before any theoretical construct could be embodied in a machine, it was first embodied on paper. Logicians always depended on inscriptive techniques to give physical form to their ideas, and different authors approached this problem in disparate ways. By centering notations and their communities of users, I show how the most abstract of sciences was rooted in the local milieus around an emerging transnational network of practitioners. Their work in logic was intertwined with local cultures and commitments. As notations proliferated, the growing diversity of symbolic techniques ultimately shaped not only the presentation but also the content of logic. My project builds on literature that has emphasized the importance of writing in the history of math, and calls for even great attention to the activities that record and perform theory on material surfaces. Focusing on writing grounds the history of math in histories of human practice.
