The two papers published here for the first time were written by Leo Strauss(1899–1973) in or around 1945, when he was teaching at the New Schoolfor Social Research in New York City. One of Strauss's colleagues atthe New School was Kurt Riezler (1882–1955). Riezler had earned a PhDin classics, but had an even more distinguished career as a practicalpolitician; he had been a high-ranking cabinet member in both Imperial andWeimar Germany and a drafter of the Weimar constitution. He had wide-rangingscholarly interests, having written books on the theoretical foundations ofpolitics, art, ancient philosophy, and the fundamental structure of social life.Because they shared an interest in the foundations of social science, he andStrauss co-taught a couple of courses in the mid-1940s (onAristotle's De anima and Descartes'sPassions of the Soul [along with Solomon Asch], and onPlato's Theaetetus [along with AlexandreKoyré]). Strauss indicated the enduring respect he had for Riezler ina eulogy he wrote for him in 1955 and republished as the concluding essay inWhat Is Political Philosophy? and Other Studies in1959.