The manuscripts from Qumran have not only revealed to us something of the “inner life” of Palestinian Judaism in the late Second Temple period, but have also provoked new ways of understanding the nature of Second Temple Judaism itself. In this essay I want to clarify, with reference to the Qumran material, the nature and origin of “Jewish sects” by posing a distinction between social segregation and heteropraxis. This distinction will in turn become useful in exploring the nature of ancient Judaism itself. The existence of a sect implies the existence of a “parent,” from which the sect obtains some of its identity but against which it matches its identity also. (This, to my mind, distinguishes a “sect” from a “movement”; in my own definition, a sect is schismatic.) What was that “parent” Judaism? Three issues in particular that arise from recent scholarship on this “Judaism” are (a) when can we first speak of “Judaism”? (b) should we more accurately speak of “Judaism” or “Judaisms”? and (c) what kind of processes best describe the development of this “Judaism” – centrifugal, centripetal or both?

While reasons for the social segregation of the Qumran sect(s) – and thus their sectarian formation in the strict sense – can in fact be plausibly reconstructed, the polemics the texts display do not reveal why, of the range of ideas and practices that Second Temple Judaism exhibits, and the variety of process of accommodation, the particular issues specified (which often amount to differences in halakhah, understanding of scriptural law, and notably calendar and purity) should have generated sects.