Renaissance libraries are not mere evidence of antiquarianism or the prerogative of bibliophiles. Publishing activity development facilitates knowledge dissemination. New editions of ancient texts are issued by printers who introduce technical innovations and collaborate with the humanists in charge of the philological accuracy. The personal marks of library owners and book readers, ex libris and marginalia, provide information about intellectual communities in their socio-economic and historical context. Examination of Renaissance physicians’ libraries through possession marks and paratexts (dedicatory epistles, addresses to the reader, prefaces) sheds light on books as tools for advancing doctrine, practice and professional skills. A case in point is a new library, 318 books of Jesuitic provenance currently in the National Library in Rome, printed between the early 16th and the mid-17th cent., whose owner, Laurentius de Rubeis, has not yet been identified. We will describe this library, discuss its utility, formulate hypotheses about its owner, and present the BUDE database centralizing data pertaining to the transmission of ancient texts in the Renaissance. Linking history of medicine and history of book reading with the intellectual and social history fuels the debate about the role of books in the transformation of a (venerable) past into present and future.