Schopenhauer offers ‘nature is not divine but demonic’ as a direct rebuttal of Spinoza's pantheism, his identification of ‘nature’ with ‘God’. And so, one would think, he ought to have been immune to the ‘Spinozism’ that became, as Heine called it, ‘the unofficial religion’ of the age. In fact, I argue, Schopenhauer's Spinozism is at least as deep as that of any of his contemporaries: his debt...