The Rare Books Collections include all works owned by the Library which were published before 1850 as well as later works which are exceptionally valuable, are numerically scarce, or have significant provenance. The collections are strongest in Catholic history and theology, but also include significant holdings in philosophy, Irish history, and French literature.
Many items in the Rare Books Collections are examples of interesting binding or printing and can be used for a study of book history.
The Sablé Collection for 19th French Studies includes works from the 19th century Romantic period including literature, history, society and culture.
The Émile Zola Collection is one of the world's most important collections about Émile Zola and includes copies of his correspondence.