From establishing a comparison between, on the one hand, the concepts of cultural anthropology that express the principles of ritual efficacy, and, on the other hand, the uses of those concepts by Ancient Greek historians, it appears that the particular concepts of performativity, mana, and psychological efficacy are formulated from a modern and generalising point of view, and do not answer the question of how rites really work – a question that has recently attracted attention in the field of ritual studies. In this article, the question of efficacy is considered in relation to a number of Greek rites and texts from across the classical and archaic periods. This analysis reveals other principles, and particularly the significance of processes capable of establishing a relationship of alterity with the world of everyday experience. This principle contributes to making ritual into a distinct mode of action.