The Birth of Tragedy
One such student was Friedrich Nietzsche: after initial support, Usener turned against him as a scholar after reading "The Birth of Tragedy". Other students included Hermann Diels, Paul Natorp, Hans Lietzmann, Albrecht Dieterich, Richard Reitzenstein, and Aby Warburg. Ulrich von Wilamowitz-Moellendorff, the leading German classical scholar of the following generation, studied at Bonn 1867-9; but tended to disagree with Usener. Their correspondence has been published.