In modern discourse about the history of science, it seems to be widely accepted that at the end of the nineteenth century, Germany was one of the leading countries in the production of science. In the past, historians of science tried to trace back a specific ‘German style’ of science that—in combination with other factors—determined this German dominance around 1900, especially in the life sciences. Considering the theoretical concept of ‘national styles’, it has to be kept in mind that around (...) 1900, contemporaries already proclaimed ‘national styles’ of science as representations of national identity. Thus, the question arises as to how far existing historiographical conceptions of national styles may include earlier claims and prejudices. Careful reconstructions of contemporary discourses on national styles and inquiries into the ‘stylisation’ of a dominant, successful ‘German style’ are necessary. One of the contemporary critics of a ‘German style’ of science was the physiologist Jacques Loeb (1859–1924), who emigrated to the USA in 1891. Loeb corresponded regularly with the physicist and philosopher Ernst Mach (1838–1916). Ernst Mach can be considered Loeb's intellectual father with whom he corresponded about strategic, philosophical, and epistemological questions. Using the Loeb–Mach correspondence, the aim of the paper is to reconstruct Loeb's conception of a ‘German style’ of science and its differences to an ‘American style’. Changes in his views are discussed as well as the roots of his views and some of their consequences. Finally, Loeb's ideas on national styles and his working profiles before and after his emigration are compared to historiographical analyses of ‘American’ or ‘German’ styles of science around 1900. (shrink)