I begin with three fundamental features of the idea of ‘secularism.’ I will want to make something of them at different stages of the passage of my argument in this paper for the conclusion—among others—that the relevance of secularism is contextual in very specific ways. If secularism has its relevance only in context, then it is natural and right to think that it will appear in different forms and guises in different contexts. But I write down these opening features of secularism at the outset because they seem to me to be invariant among the different forms that secularism may take in different contexts. It is hard to imagine that one hasn’t changed the subject from secularism to something else, something that deserves another name, if one finds oneself denying any of the features that I initially list below.