This article examines a number of racist and antisemitic interpretations of the philosophy of Spinoza put forward by German authors in the period 1880-1940. Particular attention is given to the views of völkisch authors such as Eugen Dühring and Houston Chamber-lain, and national-socialist philosophy professors such as Hans Grunsky and Max Wundt, who worked within the newly founded discipline of nazi Juden forschung. Their aim was to isolate Spinoza's thought from its wider 'Germanic' context and to present it as typically 'Jewish' - with all the negative connotations that word suggested (derivative, intellectuals, materialistic). According to Grunsky, Spinoza's hidden agenda in developing his political philosophy had been to subject the 'Aryan' peoples to the dictates of a 'new Torah'. At the same time, however, Spinoza's own interpretation of Mosaic law as a purely political legislation had helped Immanuel Kant develop a pernicious notion of Judaism as a non-religion. Through Kant's influence Spinoza's thought was open to exploitation for antisemitic purposes, just as the German-Jewish philosopher Hermann Cohen had feared. The claim that Judaism is not a religion also appears in Hitler's Mein Kampf. The suggestion that Hitler derived some ideas from Spinoza and the Enlightenment generally is still to be examined seriously.