This series comprises scholarly papers, articles, and audtio recordings of speeches and lectures by Ruth Barcan Marcus, as well as notes, outlines, and correspondence related to her writings. The bulk of materials concerns the topics of modal logic and belief, two of Marcus' foremost research interests. The paper, "Women in Philosophy," delivered at an unspecified conference or event, details both Marcus' own experience as a woman in the field of philosophy, as well as her perspective on the status and role of women in philosophy throughout her life and career.