The collection includes several thousand items of correspondence with scientists (originals, copies, clippings from the published literature), from such figures as Niels Bohr, Erwin Schrd̲inger, Willem de Sitter, David Hilbert, Moritz Schlick, and Max von Laue, as well as more obscure or controversial people. There are many files of Einstein lecture notes, manuscripts (some unpublished) and pads of his calculations. In addition, there is much correspondence involving many of the major figures of the 20th century on subjects such as literature, music, politics, pacifism, arms control, philosophy, Zionism, the founding of Hebrew University, human rights, etc. In short, the collection is a kaleidoscope of a scientist's mind and influence, as well as the interactions of the science, politics and culture of the 20th century.