[2] Later he studied medicine at Paris and Padua (where he attended Cesare Cremonini's lessons), and became physician to Louis XIII.At the age of twenty, Naudé published his first book Le Marfore ou Discours Contre les Lisbelles.[6] At the desire of Cardinal Richelieu he began a controversy with the Benedictines, denying Jean Gerson's authorship of De Imitatione Christi.[10] Mazarin's library was sold by the Parlement of Paris during the troubles of the Fronde, and Queen Christina invited Naudé to Stockholm.[6] The friend of Gui Patin, of Pierre Gassendi and all the liberal thinkers of his time, Naudé was no mere bookworm; his books show traces of the critical spirit which made him a worthy colleague of the humorists and scholars who prepared the way for the better known writers of the siècle de Louis XIV.He was a major proponent of scouring secondhand bookshops and print shops for valuable and hard to find literary works.Having bought up in every last one of them all the books, whether in manuscript or in print, dealing in any language whatever with any subject or division of learning no matter what, he has left the stores stripped and bare.It should, if possible, be situated between some spacious court and a pleasant garden, from which it may enjoy good light, a wide and agreeable prospect, and pure air, unpolluted by marshes, sinks, or dunghills; the whole arrangement so well planned and ordered that it is compelled to share nothing unpleasant or obviously inconvenient.[14] As a librarian and scholar, Naudé proposed "to direct a wealthy collector into paths of bibliothecarian righteousness"[15] as a result of his belief that the current century had advanced far beyond their predecessors with regard to the quantity and quality of the information or resources that they had access to.Naudé's knowledge and expertise left a lasting impact on both the library community and the world at large, with his influence guiding collectors, scholars, politicians, and religious leaders.In the introduction to his book, Naudé wrote that he is not an expert in the field of librarianship but he presented what he believed to be the most important ideas.Regardless whether they are ancient or modern works, if a book were held in high regard by practitioners of a particular field then it should be present in any collection.