O cenzurowaniu ksiąg w dawnych bibliotekach klasztornych

The early printed books collection held by the University of Warsaw Library contains about 300 books printed from the 15th to the 17th century, with various marks of the 17th-century library censorship. Thanks to the provenance research conducting by the Early Printed Books Department staff we can recognize that most of these books were once held in monasteries. The purpose of this article is to present various methods of censorship, notes such as: “haereticus” or “prohibitus”, the names of authors or other people contributing to the work which were crossed out, obliterated or cut out, fragments of texts concerned heretical or salacious content – removed in different ways. Censorship marks are interesting as yet poorly explored testimonies of post-tridentine spirituality. Their analysis can bring new perspectives to the studies of sociology of religion.