Son of Spinoza sheds light on the interconnectedness between Jewishness and cosmopolitanism in the oeuvre of the Danish-Jewish intellectual Georg Brandes (1842-1927). Today, the historical tradition of interconnecting these concepts has largely been forgotten, although the construction of a somewhat synonymous relation between them became a key structuring element of modern antisemitism and later Nazi ideology. In this context, Georg Brandes–his writing and practice–stands as a crucial European cosmopolitan archive, due to the great influence he enjoyed throughout the European continent. Son of Spinoza challenges the presentation of Brandes in previous research as a so-called assimilated Jew who distanced himself from Jewishness, instead recognizing Brandes’ own self-identification as a Spinozist cosmopolitan and his depiction of himself and other modern Jews as ‘sons of Spinoza’.