The Department of Special Collections holds a diverse array of material pertaining to philosophical studies. Collections of note include:

• The Arthur Lovejoy Papers: The papers span the years 1872 to 1963 and include correspondence, manuscript notes for lectures, notebooks, diaries, newspaper clippings, reports, speeches, photographs, drafts, typescripts, galley proofs, and books owned and annotated by Lovejoy.
• The Josiah Royce Collection: The Royce Collection spans the years from 1878 to 1916 and includes correspondence with members of the George B. Coale family (chiefly Mr. Coale, 1878 - 1887), his unpublished Hopkins dissertation, several manuscript compositions, photographs and lecture notes by a student in one of Royce's philosophy classes at Harvard.
• The Charles S. Peirce Papers: Collection consists of one bound holographic notebook of philosopher and mathematician, Charles S. Peirce. The notebook contains a catalog of books on logic and scholastic philosophy from Peice's personal library. Peirce also noted the estimated value of each title. Most likely, Peirce compiled the notebook, 1880-1881, at a time when he hoped to find a buyer for his library. Most of the books were acquired by the Johns Hopkins University in 1881.
• The George Boas Papers: The collection spans the years from 1920 to 1980, and consists of articles, correspondence, notebooks, reprints, short stories, and speeches.
• Philosophy Department Records: The records of the Philosophy Department range in date from 1922 to 1993, and are divided into four series: (1) Administrative Records, 1942-1989; (2) Curriculum, 1934-1993; (3) Faculty, 1922-1989; (4) Student Records, 1945-1989. Series 4 is further divided into two subseries: (1) Ph.D. Students, 1948-1989; and (2) Special/Master of Arts/Withdrawn Students, 1945-1989. The record group consists of correspondence, annual reports, alumni newsletters, student records and examinations. There are also files on various fellowships awarded within the department and information pertaining to the celebration of the centenaries of the births of Josiah Royce and John Dewey. Of special interest is correspondence with Arthur O. Lovejoy, located in the "Lovejoy Fellowship" file in Series 1.

Special Collections, including rare books and manuscripts from the George Peabody Library  and the John Work Garrett Library, holds a collection of early and important landmarks in philosophy. Recent acquisitions include first editions of literary and philosophical works by  Lou Andreas-Salome and the first edition of Spinoza's Reflexions Curieuses d'un Esprit des-Interressé sur les matieres les plus Importantes au salut, tant Public que Particulier  (1678).