This chapter surveys academic approaches to the themes of ritual purity and impurity within the ﬁelds of cultural anthropology and Islamic studies. At this stage, I am interested only in sketching the broad outlines of the debates on purity in both ﬁelds so as to situate my own approach within them. Accordingly, the chapter is divided into two main sections. The ﬁrst provides a summary of Mary Douglas’ inﬂuential theories; as shall be shown, almost regardless of setting, the same theories continue to dominate anthropological considerations of ritual purity beliefs and practices to this day (Ch. 1.1). The second section explores the varying approaches by Islamicists to Sunni Islam’s ritual purity texts, where Douglas’ theories have received a mixed response (Ch. 1.2). This exploration also provides me with an opportunity to brieﬂy sketch an outline of the purity system, the rudiments of which were ﬁrmly in place during the lifetime of Shaﬁ‘i (d. 820 CE). Appealing primarily to the recent contributions of Marion Holmes Katz, there follows a brief analysis on the degree to which normative classical Sunni tradition, and particularly its legal sphere, articulates the condition of ritual (im)purity in terms of danger and sin.