Heresy in Judaism
Various movements within the religion have been viewed heretical by those who disagreed with them.
Reprinted from The Jewish Religion: A Companion, published by Oxford University Press.
Heresy is the holding of beliefs contrary to the Jewish religion. Any attempt to study the phenomenon of heresy in Judaism has to take note of the differences in this matter between Judaism and the Christianity. The various councils of the Christian dominations met in order to define Christian doctrine, any departure from which was seen as heresy. In Judaism, on the other hand, while there are Jewish dogmas, there has never been any officially accepted formulation of these, no meeting, say, of authoritative rabbis, to decide what it is that Judaism teaches in matters of faith.
It is no accident that Maimonides, who drew up his 13 principles of the Jewish religion, was the first noted Jewish thinker to attempt a systematic treatment of the various types of heresy. Ironically, Maimonides himself was accused of heresy because of his declaration that anyone who believes that God is corporeal is a heretic! What actually happened in the history of Judaism was that a kind of consensus emerged among the faithful that there are limits in matters of faith, broad to be sure, to step beyond which is heretical.
There are a number of terms corresponding to heretic in the rabbinic sources. There are references to Jews who "deny the root principle," denoting atheism in its practical sense, that is, the attitude which, while not necessarily denying that God exists, denies that God is concerned with human life and its conduct.
Another widely used term is apikoros, not connected, strangely enough, in the rabbinic literature with the Greek philosopher Epicurus, but understood as referring to people who entertain false beliefs about the Torah and who revile its teachers. But the most frequent term for heretic is min. This word (plural minim) means a "species" and is used to denote a sectarian. For "heresy" the word, coined from min, is minut.
To give one example among many, the Talmud (Berakhot 12b) observes that when Scripture states "do not follow your own hearts (Numbers 15:39)” it refers to heresy (minut) since in another verse it is said: 'the fool hath said in his heart there is no God (Psalms 14:1).' The minim mentioned in the rabbinic literature may be the early Christians or the Gnostics but the term minim embraces all sectarians who hold dualistic views contrary to pure Jewish monotheism.
In the post-Talmudic period, among the groups to be declared heretical by the rabbinic upholders of the tradition were the Karaites; some of the rationalistic philosophers; the Shabbeteans, and the Frankists. Some of the kabbalists dubbed opponents of the kabbalah heretics for denying the 'true science', while these opponents considered the kabbalah to be heretical because of its belief in the sefirot.