In 1948 Ludwik Fleck published a paper in Polish discussing the use of humans in medical experiments, thereby addressing his peers. Though the paper has so far not been translated or studied, it has been taken to indicate Fleck’s deep commitment to ethical questions, notably the question of informed consent. In being written by a former victim of the Nazi policy and a survivor of the Holocaust also acting as an expert witness in the trial of the IG Farben in (...) Nuremberg, the paper is of interest. A scrutiny of Fleck’s text and related sources discloses, however, not only the complexity of the issue at the centre of the Nuremberg trial, but also Fleck’s unexpected stance in seemingly adducing his arguments from both the German defendants and the prosecution, heavily informed by US scientists. Further, the contentious discussion of the past in Fleck’s paper reveals its links to modern bioethical discussion. Though sometimes oblivious of that past, it still faces the same questions. (shrink)