Twenty years ago I attempted to clarify thinking about Judaism in proposing a more refined terminology which, if properly used, would eliminate the all too frequent fallacies of equivocation by which discussion is bedevilled (‘Defining Judaism:Some Ground-Clearing’, Jewish Journal of Sociology, VII, 2, 1965, pp. 153–75). It is not my purpose here simply to exhume that article: on the other hand, I do not feel that I can usefully begin again ab initio, since the situation has not been radically transformed as it had been in the thirty years preceding 1965. The two decades since and including the Six Days War have witnessed much entrenchment of position, intensification of doctrinaire assertion, and heightening of enthusiasm, but little inclination (until the Lebanon War began to stimulate it in Israel) towards questioning what have become popularly accepted axioms:and it is still the case that anyone who dares to question the assumption that Israeli national sovereignty now is, and for all time will remain, a sine qua non for the survival of Judaism will not get much of a hearing. What I intend here is to reconsider my earlier findings from the angles of belief, authority, and peoplehood, particularly since I feel that the last-mentioned had perhaps been allowed inadequate weight in my previous endeavour. I consequently repeat here, for convenience of reference, the terminological distinctions proposed in that article, together with the tentative working definition of Judaism with which it concluded. I doubt its usefulness, save from a negative standpoint, i.e. what it excludes. But if we are to consider peoplehood, we need to know who, and what, is a Jew: and the only uniquely valid definition of a Jew that satisfies me is a transmitter of Judaism. The question seems to me otherwise meaningless without some terms of reference, e.g. who is a Jew for purposes of joining synagogue X, or speaking for Anglo-Jewry or world Jewry at forum Y, or qualifying for Israeli citizenship under the law of return, etc. Here, then, is my tentative formula: