This paper focuses on the memory of António Ribeiro dos Santos and on the sociability networks of the first chief librarian of the Royal Public Library of the Court. The lifestyle of the academic and librarian is mirrored on the rules of civility he adopts in his correspondence to academics and intellectuals. The networks of literary sociability of António Ribeiro dos Santos are national and international, and they do not exclude the participation of educated and erudite women. Connecting some topics of the debate of ideas that he feeds himself, it is worth mentioning his pioneering efforts to uphold moderation of judicial sentences and partial abolition of the death penalty in Portugal. His philosophical and political thought allowed him to take stock of the great cultural changes brought by the Enlightenment, and to bring the legacy of modern legal utilitarianism closer to the catholic rationalism and humanism values.