Defences of classical learning in St. Augustine's De Doctrina Christiana and Erasmus's Antibarbari

New information technology can be an invaluable aid to research in the history of ideas provided it is built on scientific foundations. This article discusses the case of Diderot and D'Alembert's Encyclopédie and analyses its use of earlier dictionaries (the Dictionnaire de Trévoux, Chambers's Cyclopaedia and Moréri's dictionary). It also shows how neglect of existing research in the history of ideas and ignorance of how these eighteenth-century European publications were elaborated, combined with inappropriate use of software for detecting plagiarism, have led to totally mistaken findings. These findings, widely publicised thanks to the Internet, constitute a real danger for future research. The article concludes that the intellectual community urgently needs to invest seriously in the digital humanities in order to safeguard future research.