Abstract: Although it is well-known that Locke denied toleration to atheists, relatively little has been said in the scholarship about what exactly this denial amounted to. This article attempts to fill in this gap by considering, amongst others, Locke’s writings on education and the conduct of the understanding. It first analyzes Locke’s definition of atheism. It then shows how in fact Locke distinguished different strands of atheism and how he thought one becomes an atheist. Finally, the article sketches out Locke’s views about how to deal with these different strands. In offering an extensive discussion of Locke’s response to atheism, the article portrays both the philosopher’s calmness and consistency.