Geiger argued Judaism, not Christianity, founded Western civilization

Evidence

In essence, Geiger sought to establish definitively the foundational role played by Judaism in the advent of both Christianity and Islam. Above all, however, Geiger sought to undermine the privileged status that Christianity accorded itself in claiming to be the basis of Western civilization, an honor that he believed belonged to Judaism. — Ivan Davidson Kalmar, Derek Penslar, Orientalism and the Jews, 379

Categorization

• DEFINE: Establishes the revisionist move: a Jewish historian claiming civilizational primacy for Judaism against Christian supersessionism.