“The similarities between this phenomenon and Christian monasticism on the one hand and the condition of the perfecti or bonshommes among the Cathars on the other, are especially striking, despite the clear divergences resulting from the different attitudes of Judaism and Christianity toward celibacy. The Nazirites are not simply hasidim in the well-defined sense of the Book of the Pious and German Hasidism.
But it is evident that we are dealing with a parallel stratum in the Jewish communities, many of whose members undoubtedly also inclined toward the more radical demands of German Hasidism. At the end of his halakhic work Rabad himself picked out of his talmudic material precisely that definition of hasiduth that most closely approximated the mentality of the German Hasidim.
R. Ezra of Gerona, in his commentary on the aggadoth, also calls Jacob the Nazirite by the name Jacob the Hasid. What is important for us is the existence of a stratum with society that by its very definition and vocation had the leisure for a contemplative life. It goes without saying that such a stratum could give rise to men with mystical tendencies.
Members of this group are also mentioned in the earliest kabbalistic sources after Jacob the Nazirite as representatives of a mystical tradition; the names may as well be those of historical personalities as of fictitious figures appearing in pseudepigraphic documents. Indeed, it is precisely the fictitious character of these names of perushim and nezirim that seems so characteristic of the mood prevailing in these kabbalistic circles.”
Gershom Scholem, Origins of the Kabbalah, pp. 229-31.