The Heidegger Archive consists of the Nachlass of Helene Weiss, which is held at Stanford Library’s Department of Special Collections. It is a collection of detailed class notes (Nachschriften) taken by Helene Weiss and her associates during lecture courses and seminars given by Martin Heidegger from 1920 on. It forms a clearly presented corpus of Heidegger's teaching and philosophy in one of the most important periods of his philosophical career.

Helene Weiss (1901-1951) was a student of Martin Heidegger from 1920 until 1934, when she was driven into exile in Switzerland because she was Jewish. She received her doctorate in Basel under Prof. Schmalenbach. Eventually she settled in England and taught mainly at the University of Glasgow. She authored a book that earned Heidegger’s praise, Kausalität und Zufall in der Philosophie des Aristoteles. [Causality and Accident in Aristotle’s Philosophy] (Basel: Verlag Haus zum Falken, 1942).

Because she was absent from Freiburg University for family reasons during some of the semesters, Helene Weiss filled out her own notes from Heidegger's lectures and seminars by copying the class notes of H. Mörchen and other students. She was part of a group of students (Mörchen himself, Hans W. Loewald, Bondi, Franz-Josef Brecht, et al.), who used to meet after Heidegger's lectures to compare their own notes and to complete them with precise quotations from Greek texts and translations.

Dr.Weiss’ notes were long held by her nephew, Prof. Ernst Tugendhat, an alumnus of Stanford University. While he was teaching at the University of Heidelberg in the 1970s, he made the texts available to Prof. Thomas Sheehan and other scholars. Stanford University acquired the collection from Professor Tugendhat in 1992.