In this article, I discuss Anselmian theism, which is arguably the most widely accepted form of monotheism. First, I introduce the core theses of Anselmian theism and consider its historical and developmental origins. I contend that, despite its name, Anselmian theism might well be older than Anselm. I also claim, supporting my argument by reference to research in the cognitive science of religion, that, contrary to what many think, Anselmian theism might be a natural result of human cognitive development rather than a mere philosophical artefact. Second, in the course of explaining the merits of Anselmian theism, I argue that this doctrine seems to benefit from at least three virtues. Third, I discuss existing arguments against Anselmian theism and maintain that most of them can be classified into three types. Finally, I suggest a novel strategy on the basis of which it is possible to defend Anselmian theism from these arguments.