In order to substantiate this claim, I will discuss the question how to characterise the authorship of early modern dissertations within a contemporary metadata schema. The problems I describe arose during the compilation of a dataset if early modern dissertations across disciplines which were published between approx. 1550 and 1800 and preserved in French university libraries and the national library of France. Both the union catalog of French university libraries (SUDOC) and the general catalog of the BNF provide SRU interfaces allowing for the retrieval of limited datasets. Relevant data were retrieved and parsed using Python scripts by the author. The dataset itself still needs to undergo peer review and will hopefully be published in a separate data paper.