R. Israel b Shabbetai Hapstein of Kozienice (1733–1814), hasidic zaddik and preacher, born in Apta; one of the first propagators of Hasidism in Congress Poland. His teachers were R. Samuel Shmelke Horowitz of Nikolsburg, R. Dov Baer the Maggid of Mezhirech, R. Elimelech of Lyzhansk, and R. Levi Isaac of Berdichev, with whom he was on friendly terms. In his early years, R. Israel withdrew from society and became an ascetic. After the death of his father, a poor bookbinder, he moved to Przysucha where he earned his living as a teacher (melammed). He then settled in Kozienice where his eloquent preaching gained him the appellation the "Maggid of Kozienice."R. Israel's homilies were notable for their elegant structure and lucid exposition, even though they included much kabbalistic symbolism, and had a great impact on his listeners. He would admonish them "with pleasing and sweet persuasion and not with hard words" (Avodat Yisrael, Avot). On the role of the preacher he taught: "He who reproves people and teaches them the Law and the word of G-d must have insight into the heart of every single one of them, even of the very wicked."

R. Israel became noted for his activity as a zaddik. Many followed him because of his whole-hearted approach to the worship of G-d and his ecstatic mode of prayer through Devekut. According to Israel, the principal duty of the zaddik was to give spiritual guidance to his followers and assist them in divine worship. The devotion to G-d by the zaddik is a dynamic action through which those under his protection also attain devotion to G-d. Thus the zaddik elevates the spirit of the average man and brings him nearer to the Creator, which is the aim of Hasidism. However, the simple man will never attain the heights which the zaddik himself reaches. As a "practical zaddik" R. Israel gained great popularity, actively assisting his followers apart from his duties of spiritual guidance. He thus cared for the welfare, children, and livelihood of his Hasidim and even distributed remedies and amulets. The Mitnaggedim sharply criticized him for this activity while the Hasidim justified it, explaining that the amulets contained his name only. R. Israel's fame also reached high-ranking Poles, and he apparently had connections with the family of the Polish prince Czariorski. He was alive to public affairs and during the period of the grand duchy of Warsaw was to have participated in a convention of delegates of the Polish communities convening in Warsaw mainly to discuss the heavy taxes imposed on the Jews. R. Israel took steps against the opponents of Hasidism and tried, unsuccessfully, to prevent the printing of anti-hasidic works appearing in Warsaw in the late 18th century. A man of the people, he spiced his discourse with proverbs. With his friend R. Jacob Isaac ha-Hozeh of Lublin he was among the principal disseminators of Hasidism of the school of R. Israel b. Eliezer Ba'al Shem Tov in the interior of Poland. He had a profound knowledge of both traditional and esoteric learning, and participated with the greatest scholars of his time in a halakhic discussion on the question of the agunah. His principal halakhic work is Beit Yisrael (Warsaw, 1864). His tractates on the Kabbalah testify to his great esoteric knowledge. A hasidic story relates "that before he traveled to the Maggid of Mezhirech he studied 800 books on Kabbalah and after all that when he came to the holy Maggid of blessed memory he realized that he had not yet learned anything" (Toledot Adam le-Shabbat Hanukkah); his writings on Kabbalah are Or Yisrael, (Czernowitz, 1862); Ner Yisrael, (Vilna, 1822); and others. His principal work on Hasidism is Avodat Yisrael (Yozepof, 1842).