At this point Adorno reversed his earlier priorities: now his musical activities came second to the development of a philosophical theory of aesthetics. Thus, in the middle of 1929 he accepted Paul Tillich's offer to present an habilitation on Kierkegaard, which Adorno eventually submitted under the title "The Construction of the Aesthetic". At the time, Kierkegaard's philosophy exerted a strong influence, chiefly through its claim to pose an alternative to Idealism and Hegel's philosophy of history. Yet when Adorno turned his attention to Kierkegaard, watchwords like "anxiety," "inwardness" and "leap"—instructive for existentialist philosophy—were detached from their theological origins and posed, instead, as problems for aesthetics. As the work proceeded—and Kierkegaard's overcoming of Hegel's idealism was revealed to be a mere interiorization—Adorno excitedly remarked in a letter to Berg that he was writing without looking over his shoulder at the faculty who would soon evaluate his work. Receiving favourable reports from Professors Tillich and Horkheimer, as well as Benjamin and Kracauer, the University conferred on Adorno the "venia legendi" in February 1931; on the very day his revised study was published, 23 March 1933, Hitler seized dictatorial powers.