 In 1919 Cassirer was finally offered professorships at two newly founded universities at Frankfurt and Hamburg under the auspices of the Weimar Republic. He taught at Hamburg from 1919 until emigrating from Germany in 1933. During these years Cassirer completed his three-volume Philosophy of Symbolic Forms [Cassirer 1923, 1925, 1929b], which broke fundamental new ground beyond the neo-Kantianism of the Marburg School and articulated his own original attempt to unite scientific and non-scientific modes of thought (“symbolic forms”) within a single philosophical vision. In 1928 Cassirer offered a defense of Weimar [Cassirer 1929a] at the University’s celebration of the tenth anniversary of the Republic, and in 1929–30 he served as the rector of the University, as the first Jew to hold such a position in Germany. In the Spring of 1929 Cassirer took part in a famous disputation with Martin Heidegger in Davos, Switzerland, where Heidegger explicitly took Cohen’s neo-Kantianism as a philosophical target and defended his radical new conception of an “existential analytic of Dasein” in the guise of a parallel interpretation of the philosophy of Kant [Heidegger 1929]. Cassirer, for his part, defended his own new understanding of Kant in the philosophy of symbolic forms – against Heidegger’s insistence on the ineluctability of human finitude – by appealing to genuinely objectively valid, necessary and eternal truths arising in both moral experience and mathematical natural science (see [Friedman 2000] [Gordon 2010]).