Abstract: While the Lettre de Thrasybule à Leucippe is marked by its criticism of all religions, those that prohibit human sacrifice, such as Christianity, seem morally preferable because they are compatible with secret unbelief. Focusing on the figure of Leucippus, this paper analyzes the effects of superstition on female subjectivity and the strategies deployed in the text to guide disbelieving female readers toward modesty and concealment.