as an Austrian of?cer in the First World War; afterwards he was forced to return to Poland and then because of his revolutionary political activities to emigrate to Germany; with the rise to power of the Nazis he had to ?ee to France and then Americawhilehisfamily,whichremainedinEurope,perishedinNaziconcentration camps. Our own acquaintance with the work of these two authors is also indebted to historical context (under incomparably more fortunate circumstances): the revival of Marxist scholarship in Europe in the wake of the student movement and the p- fessionalization of history of science on the Continent. We hope that under the again very different conditions of the early twenty-?rst century these texts will contribute to the further development of a philosophically informed socio-historical approach to the study of science.