Ruth's research focuses on Robespierre, the history of social science, and feminist political theory. She is the author of 'Fatal Purity: Robespierre and the French Revolution' (Chatto and Windus, 2006). She is Affiliated Lecturer and College Fellow at Gonville & Caius College, Cambridge.

Ruth convened the 'Writing a Biography' course for the MRes at CELL in 2007-8, and remains an academic visitor at CELL.