Starting from the discussion of the premiere of Ithaka (Landestheater Darmstadt 1967) and its context, the paper contends that the piece, written by Gottfried Benn half a century earlier, cannot be merely read as an essayistic dialogue about scientific debates of the late 19th and early 20th centuries, as an autobiographic showdown behind the mask of Dr. Rönne or even as a sombre anticipation of Nazism. In fact, a close reading of the text and its multi-layered, masterly dramatic construction shows the avant-gardist openness of Ithaka, which can be considered as a theatrical experiment: the author tests on fictitious characters affected by ‘cerebral distortions’, reflecting disparate tendencies of the fin-de-siècle epistemology and philosophy, and observes the consequences of such a collision up to its tragic ending.