Rosenkötter reconsiders Freud's 'non vixit' dream, starting from associations in 'The Interpretations of Dreams'. Although it is Paneth and Fliess who appear in the dream, many details point to Freud's teacher, Brücke. (In the dream the pupil has assumed the teacher's role.) Freud's scientific ideal was moulded on Brücke's apostolic positivism, which proved an obstacle to the hermeneutic procedures of the new psychology. With regard to the birth of psychoanalysis, the author feels that Freud's ambivalent dream of tyrannicide may have been aimed at positivism as represented by Brücke.