Concern for purity led to the expulsion of lepers, those impure because of contact with the dead, and those “suffering from a discharge” of bodily fluids, from the camp of the Israelites as described in Book of Numbers 5:1-4. Lepers especially were considered not only unhealthy but ritually and ethically unclean, due to the prevalent belief that such an affliction implied some moral guilt on the part of either the individual or the leper’s parents. Elsewhere in the Hebrew scripture we hear of the practice of herem, placing a “ban” on certain things, such as the spoils of war or the results of ritual sacrifice. In biblical usage, to ban an item was to dedicate it totally to the Lord. Later Jewish tradition used the term herem to apply to a kind of excommunication. When authenticated instances of heretical views came to the attention of rabbinical authorities, they could banish the culprit from the community. The philosopher Baruch Spinoza (1632-1677), for example, was excommunicated from the Sephardic community for his insistence on the primacy of reason and for views judged to be pantheistic. Earlier a Portuguese Jew named Uriel da Costa (1585-1640) underwent formal excommunication twice and endured public humiliation for his unacceptable views. Some interpret both Spinoza and da Costa as examples of a clash between Enlightenment views and traditional Jewish beliefs.