"Nothing in theological content will persist unaltered, and everyone will have to face the test of immigrating to the secular, to the profane." After 1,800 pages a personal remark: This quote from Theodor W. Adorno had always irritated him and busy. Almost a confession. It reads like the summary of the company that Jürgen Habermas has now published. The result of a twenty-year retreat that combines monastic and scholar rooms: the way back, an attempt to tell the story of the post-metaphysical age.