Dov Baer of Lubavitch
Hasidic scholar wrote extensively on the mystical mind.
Reprinted from The Jewish Religion: A Companion, published by Oxford University Press.
Dov Baer of Lubavitch was a Hasidic master (1773-1827), who was successor to his father, Rabbi Shneur Zalman of Liady, in the leadership of the intellectual tendency in Hasidism known as Chabad. He is known as Dov Baer of Lubavitch (the Russian town where he settled) and as the Middle Rebbe, that is, the master who came in the middle between his predecessor and his successor as Chabad leaders.
By all accounts, Dov Baer was a genuine mystic (his valet reported that he would not infrequently go into a trancelike state in which he was totally unaware of his surroundings) but was also a capable organizer who drew up plans for a farming enterprise through which his followers would be able to earn an honest living while having sufficient time to devote to contemplation.
Dov Baer developed in a host of works the contemplative ideas of his father. Especially noteworthy in this connection are the two lengthy missives he wrote for the guidance of his followers: Tract on Contemplation and Tract on Ecstasy. The latter is one of the most remarkable documents on Jewish spirituality in the whole history of Jewish thought, a unique analysis of the mystical mind. In this tract, Dov Baer, while believing in the high value of ecstatic states that result from profound contemplation on the divine, sternly warns his followers against the forms of sham ecstasy in which there is too much of selfhood or which are sought by the worshipper with the express intention of obtaining cheap thrills from the ecstatic state, as he would from imbibing alcohol.
Like his father, Dov Baer believed that deep in the recesses of the Jewish psyche there is a "divine spark" of God Himself so that, at the highest stage of contemplation, this spark is rekindled and God meets Himself, so to speak.
In Dov Baer's scheme, contemplation on the whole kabbalistic scheme in which all worlds evolve from the Ein Sof through the sefirot down to our lowly world, is not only an extremely elevated form of divine worship but has the effect of refining the character of the worshipper. Contrary to the opinions of some moralists that character defects can be rectified by a direct onslaught, Dov Baer taught that it is only through contemplation on the divine glory and majesty that the character can really be improved and strengthened.
Opponents of Chabad were especially critical of Dov Baer's attempt to explain the kabbalistic mysteries in a rational way. Such an attempt, they protested, turned the kabbalah into a philosophical system entirely accessible to the human mind instead of a body of revealed truth which the human mind can only hope to apprehend, but never actually comprehend.