Judging by most contemporary accounts, the virtues of cross-disciplinary research, teaching and scholarship are above reproach. Conference organisers announce with pride that ‘l’interdisciplinarité a porté ses fruits’; governments and universities sponsor ever-growing numbers of interdisciplinary research teams. Such activity is especially pertinent to eighteenth-century studies. The Republic of Letters inspired scholars, scientists, artists, and writers to engage in spirited, multilingual and long-term correspondence with colleagues throughout Europe. As many contributors to this...