These records are described by topic, title of lecture, article or other work, or course title and are arranged into three series: General; Writings and Research; and Writings by Others. Folder titles have been maintained as they were encountered by processing archivist.

The General series contains one folder of correspondence, City Planning Committee records, and a binder of short essays on aspects of New School history.

The bulk of these files document Kallen's scholarly research, writings, and instruction during the 1930s-1960s and contain writings in the form of course and paper outlines, notes, manuscripts, annotated typescripts by him and others; along with research material such as clippings, programs, journals, and other printed material. These files are titled and ordered by topic, title of lecture, article or other work, or what may be a course title. Many topics center around religion and Kallen's work with Jewish organizations, such as the World Jewish Council and Farband-Labor Zionist Order during the 1950s-1960s. Some undated notes and outlines contain Harvard blue books, possibly stemming from Kallen's time there as graduate student and lecturer. His teaching work at the New School is documented throughout these files, such as his class reading lists. Of note are drafts and correspondence related to his play, The Book of Job: as a Greek tragedy, restored by Horace M. Kallen.

The Writings by Others series consists of offprints, journals and other printed publications, along with unpublished reports and papers, covering topics in philosophy and the social sciences. They are arranged alphabetically by author or, in the absence of author, journal title. Although offprints and journals will also be found in the Writings and Research series, the items in this series were encountered without notes or accompanying documents. Languages of publication are divided evenly between English and German, with a smaller number in French. Some items are inscribed to Kallen. Stamps and ephemera found with these materials, as well as one publication post-dating Kallen's death, indicate that they may have originated elsewhere and were possibly added while this collection was housed in Fogelman Library.