Tolerance and pluralism seem to draw on the same criterion of legitimacy. The liberal case for tolerance, however, leads to a series of paradoxes, including Popper's paradox of tolerance according to which tolerating theintolerant is self-defeating. Spinoza's defense of tolerance as it emergesfrom his Theological-Political Treatise and his Ethics is more pervasive and much more encompasssing than the liberal justification. Spinoza justifies tolerance as a private and public virtue as well as on prudential grounds. Although Spinoza's conception of tolerance appears in significant respects paradoxical and contradictory - e.g., it is puzzling why Spinoza, the philosopher of reason, should avocate tolerance of religious superstition that may lead to oppression and violence - it is ultimately coherent and relevant to contemporary debates provided it is understood dialectically. The article seeks to present Spinoza's dialectic of tolerance by placing it in the context of his philosophy and of the political conflicts that marked Dutch society during his lifetime. The article then explores the relevance of Spinoza's theory for a post-Enlightenment justification of tolerance and pluralism. The article concludes that although Spinoza focuses on reason and post-Enlightenment pluralists on identity (and hence differences), Spinoza's theory is in many ways compatible with a pluralist defense of tolerance which is arguably superior to traditional liberal defenses.