Herbert Mehrtens‘ work and the implications of the historical ideas he advanced went beyond the history of any single discipline. The article therefore addresses three broad issues: (1) Mehrtens‘ reconceptualization of mathematical modernism, in his field-changing book Moderne—Sprache—Mathematik (1990) and other works, as an epistemic and cultural phenomenon in a way that could potentially reach across and also beyond the sciences and also link scientific and cultural modernisms; (2) the extension of his work to the history of modernity itself via the concept of “technocratic modernism”; (3) his seminal contributions to the historiography of the sciences and technology during the National Socialist period, focusing on his critique of claims that mathematics, the natural sciences and technology were morally or politically “neutral” during or after the Nazi era, and on his counter-claim that mathematicians and other scientists had in fact mobilized themselves and their knowledge in support of Nazism’s central political projects. Taken as a guide for understanding science-politics relations in general, Mehrtens‘ work was and remains a counterweight to the political abstinence adopted by many who have followed the “cultural turn” in history of science and technology. In the broadest sense, the article is a plea for the culturally relevant and politically engaged historiography of the sciences and humanities that Mehrtens himself pursued.

Epistemological issues associated with Cantorian set theory were at the center of the foundational debates from 1900 onward. Hermann Weyl, as a central actor, saw this as a smoldering crisis that burst into flames after World War I. The historian Herbert Mehrtens argued that this “foundations crisis” was part of a larger conflict that pitted moderns, led by David Hilbert, against various counter-moderns, who opposed the promotion of set theory and trends toward abstract theories. Among counter-moderns, L.E.J. Brouwer went a step further by proposing new foundational principles based on his philosophy of intuitionism. Meanwhile, Felix Hausdorff emerged as a leading proponent of the new modern style. In this essay, I offer a reassessment of the foundations crisis that stresses the marginal importance of the various intellectual issues involved. Instead, I offer an interpretation that focuses on tensions within the German mathematical community that led to a dramatic power struggle for control of the journal Mathematische Annalen.