This article explores the complex and contested intellectual relationship between two of the key thinkers of the Early Enlightenment: Spinoza and Bayle. The key issue of contention between them is not, it is argued, the question of the existence and nature of God, but their profoundly contrasting visions of the nature of philosophy as a politically emancipatory practice. The article analyzes Bayle's rejection of Spinoza's systemic certainty, and the significance of this rejection in relation to Bayle's own anti-systemic philosophy of (...) openness and incompletion. This contrast between Bayle and Spinoza is deployed to clarify the interpretation of Bayle's theory of toleration and of his late writings. (shrink)