Rabbi Israel Salanter (1810–1883), founder and guiding light of the Mussar movement, is one of the most underappreciated modern Jewish thinkers. Embedded within his traditional language is a profound understanding of the nature of human motivation and a vision that was ahead of its time. He felt that only profound insight into human psychology could supply modern Jews with the tools that they needed to face the challenges of a rapidly changing society and new technologies. Rabbi Salanter argued that human motivations are not transparent; a purely intellectual approach to self-improvement can blind people to the hidden impulses that drive us toward both proper and improper behavior. Ohr Yisrael includes his teachings that only a richer psychology that accounts for subconscious and irrational motives can help modern Jews improve their characters and better their service of God. These collected texts, gathered in a bilingual edition for the first time, with a new translation and commentary by Rabbi Irving Yitz Greenberg and Rabbi Justin Pines, offer readers not only an understanding of a creative historical figure, but insight into the workings of the human personality and religious soul.