The century following the year 5250 - referred to above - witnessed a phenomenal flourishing and revolutionary expansion in the study of, and preoccupation with, the Kabbalah. It was the age of R. Mosheh Cordovero, whose expository works - of remarkably lucid style - have become primary sources. Immediately after him followed R. Isaac Luria, the Ari ("Lion"), whose all-encompassing teachings soon were recognized universally as final and authoritative and had an impact on the totality of Jewish life. It was an age that ushered in an altogether new era: R. Isaac Luria declared that as of then it is not only permissible but a mitzvah, a duty, to reveal Pnimiyut haTorah, the esoteric part of Torah. (As explained in Igeret Hakodesh, sect. XXVI. See R. Chaim Vital, Sefer Hagilgulim 12, ch. 32: "In this our present era, which is the last era, it IS necessary to reveal chochmat Ha'emet (lit. 'the wisdom of Truth'; the mystical teachings of the Torah) in order that Mashiach will come, as stated in Tikunei (Zohar) that by merit of the Zohar the King Mashiach will be revealed.")

Ever since then there has been a continuous flow of mystic works appearing in print: the writings and teachings of the aforementioned R. Mosheh Cordovero and R. Isaac Luria, and of their disciples; commentaries on the Zohar; mystical expositions of the Bible and Rabbinic texts; special tracts propagating the principles and premises of the Kabbalah and introducing the novice to them. All these works, mostly written by scholars whose authoritative expertise in the Talmudic-Halachic branches of the Torah equalled their mastery of the Kabbalah, stressed the significance of, and need for, an intensive study of Pnimiyut haTorah - the very soul of the Torah which animates and illuminates the body of the exoteric tradition.

(See especially R. Isaac ben Immanuel de Lattes' approbation for the first printing of the Zohar (prefacing most editions since then); R. Mosheh Cordovero, Or Ne'erav\ (parts I-V);\ft.2 Sha'ar Hahakdamot, Introduction; Or Hachamah, Introduction; Shomer Emunim; and so forth.

These, and many others, went to great lengths to refute in detail the various objections raised to an extensive study of mysticism. They state emphatically the admissibility and necessity thereof nowadays, in spite - and precisely because of - the spiritual decline of our own times.

Note also R. Chaim Vital's resolution of the seeming contradiction between this claim on the one hand and the restrictive prerequisites referred to above, by stating: "If we were to apply the prerequisites as strictly as they appear to be, no one would be able to pursue this study unless he had an instructor as great as R. Shimon bar Yochai to resolve all problems encountered. Thus it seems to me that the mitzvah to pursue this wisdom remains in effect, provided one has adopted the following approach: when seeing bewildering passages which may arouse doubts, one must think 'If this matter appears to be in vain - it is on MY account (lack of knowledge...) that is, I do not understand it because of the deficiency of MY intellect, and not, Heaven forbid, because the subject-matter is questionable....

The study (of mysticism) is prohibited only to him who is unable to stand in the Palace of the King and may come to heresy, Heaven forbid, because he thinks himself very wise and without any deficiency on his part. See Kol Ramah on Zohar III:141a (quoted in Nitzutzei Zohar, ad loc\ft.1.); also Eitz Chayim, end of Introductions. Moreh Nevuchim I:ch. 31-34, and III:ch. 26 and 50.

See the frequent discussion of this theme in Likutei Sichot (see there index, Hafotzat Hama'ayanot; Chassidut; Pnimiyut Hatorah); and the anthology Or Hachassidut.)

However, this open dissemination of the Kabbalah, which began gradually in mediaeval times and expanded drastically from the sixteenth century onward, remained restricted basically to the scholarly world. Two centuries passed since R. Isaac Luria before there was a further development bringing the Zohar's vision of the 'end of days' a major step closer to realization.