the doctrine of Mainstream Hasidic "Popular Tzadikism" developed, especially by Elimelech of Lizhensk. In this, while true deveikut was unattainable by the common folk through their own efforts, the substitution of attachment, sometimes called "Deveikut", to the Tzadik enabled everyone to perceive and experience Divinity. This was the first time that Jewish mysticism, embodied in the elite esoteric deveikut of the Tzadik, was combined with practical, popular social doctrine and movement. Tzadikism, and its parallel worship of God through materiality, became the most distinctive feature of Hasidic Judaism, distinguishing Hasidism from other forms of traditional Judaism. The Tzadik embodied Divinity, through Hasidism's adaption of the Kabbalistic notion of Yesod-Foundation, becoming the channel of Divine spiritual and physical blessing to his followers. The Russian Chabad school of Shneur Zalman of Liadi and his successors became the exception from Mainstream Hasidism, in seeking to communicate the elite esoteric dimension of deveikut as widely as possible, through its approach of intellectual investigation of Hasidic thought. In this, as in the different Polish Peshischa-Kotzk school that stressed personal autonomy, the main role of the Tzadik was as teacher in Habad, or mentor in Peshischa. The most extreme form of Mainstream Tzadikism, sometimes opposed by other Hasidic leaders, was embodied in "Wonder-working" Rebbes, for whom Divine channelling of blessing through theurgic practice became central, at the expense of Torah teaching. Hasidism developed the customs of Tish (gathering), Kvitel (request) and Yechidut (private audience) in the conduct of the Tzadik. Deveikut and Teshuvah Teshuvah, often translated into English as "Repentance", literally means "Return" to God in Judaism. Halachic codes identify its defining stages in personal spiritual repentance and atonement from sin. Musar literature generally see its role in broader self-understanding, spiritual growth, and personal fidelity. Hasidic thought, based upon Kabbalistic exegesis, gives it a mystical ascending structure. It interprets two levels of return, "Lower Teshuvah" (Lower Return to God), and "Higher Teshuvah" (Higher Return). In Hasidic philosophy, Teshuvah does not only involve repentance and rectification of previous spiritual faults. Rather, as the Baal Shem Tov taught, even perfectly righteous Tzadikim need to return to God, in the higher Teshuvah of continual ascent in holiness. With new revelations of mystical Divinity, come new awareness of Bittul (self-nullification) and desire for God in Deveikut. According to Kabbalistic exegesis of the Hebrew word "Teshuvah" (תשובה), it can be read as "Returning the letter hei" (תשוב-ה). The Tetragrammaton essential Divine