Rabbi Menachem Mendel of Kotzk (1787–1859)

Rabbi Menachem Mendel of Kotzk, better known as Kotzker Rebbe, was a Hasidic leader. Born to a non-Hasidic family in Goraj, near Lublin, Poland, he became attracted to Hasidim in his youth. He was known for having acuqired impressive Talmudic and Kabbalistic knowledge at a young age. He was a student of the Rebbe Reb Bunim of Peshischa, and upon the latter's death attracted many of his followers. The Kotzker Rebbe is well known for his incisive and down-to-earth philosophies, and sharp-witted sayings. He appears to have had little patience for false piety or stupidity.

From wikipedia