Tonight is the yahrzeit of Menachem Mendel of Kotzk (aka The Kotzker Rebbe):

Menahem Mendel of Kotzk (1787-1859) was one of the outstanding and most original leaders of the hasidic movement. Born near Lublin into a non-hasidic family, he was attracted to the movement in his youth and became a disciple of Jacob Isaac ha-Hozeh (“the Seer”) of Lublin, of Jacob Isaac (“The Holy Jew”) of Przysucha, and later of Simhah Bunem of Przysucha. His teachings, although part of Hasidism and in some ways continuing its classic lines of thought, are in other ways diametrically opposed to the teachings of the founder of Hasidism, Israel ben Eliezer Ba’al Shem Tov (the Besht). Menahem Mendel indeed meant a revolution within Hasidism, and would-be followers flocked to his side. While the Besht emphasized love, joy, and compassion for this world, Menahem Mendel demanded constant tension and an unmitigated militancy in combating this egocentricity. The Baal Shem Tov was kind to everyone, and Menahem Mendel was harsh. In Medzibozh there was light, but in Kotsk there was fire where furious zeal of the prophets of old came back to life. Classical Hasidism tried to reach all the Jews, while Menahem Mendel was interested only in the select, the few. Above all in importance to Menahem Mendel was the quest for absolute truth which he taught could be reached only through utmost freedom. Such freedom meant not to give in to any outside pressures, it meant not to conform, nor try to please oneself or anyone else. Adopting a non-hasidic approach for the day, Menahem Mendel taught that truth could be discovered through in-depth study of Torah and Talmud, a method touted by the Lithuanian mitnagdim, the ideological rivals of the hasidim. Finally, Menahem Mendel taught that the true worship of God is not in finding the truth, but rather in the honest search for it.

Source. Nods to Esti for the heads-up.