Danny Saunders One of the main characters of the novel, along with Reuven Saunders. Danny, a Hasidic Jew, struggles to combine his father's strict religious practice with his own more secular interest in human psychology.
Rabbi Isaac (Reb) Saunders Danny's father, and the leader of his Hasidic sect. Reb Saunders personifies the Hasidic "rebbe" (from "rabbi," or teacher) in that he is strict and serious and obeys Jewish law to the letter.
Reuven Malter Danny's friend and the narrator of the novel. Like Danny, Reuven is an Orthodox Jew. But unlike Danny, Reuven can enter the secular world while still retaining his Orthodox Jewish identity because he is a Modern Orthodox Jew rather than a Hasidic Jew.
David Malter Reuven's father, who teaches Jewish studies at a yeshiva.
Manya The Malters' Russian housekeeper.
Mr. Galanter Reuven's softball coach.
Davey Cantor The boy on Reuven's softball team who warns Reuven that Danny's yeshiva team members are "murderers."
Tony Savo A patient who shares Reuven's hospital room. Mr. Savo apparently is a washed-up professional boxer.
Billy Merrit A young boy who, along with Mr. Savo, shares Reuven's hospital room. Billy is completely blind, which greatly upsets Reuven and Reuven's father because they fear that Reuven could end up the same way if his wounded eye doesn't heal properly.
Roger Merrit Billy's father, a caring man who dotes on his son.
Dr. Snydman The doctor who successfully operates on Reuven's damaged left eye.
Mrs. Carpenter The nurse who cares for Reuven, Mr. Savo, and Billy in the hospital.
Professor of Talmudic study at Samson Raphael Hirsch Seminary and College. Danny and Reuven study the Talmud with him. Although Reuven comes intellectually alive in his classroom, Rav Gershenson asks him not to use his father's — Mr. Malter's — methods of explaining the Talmud in his classroom.
Professor Appleman Danny's psychology professor at Hirsch College. Appleman specializes in experimental psychology, a field of study that Danny initially dislikes but later accepts as valid, and convinces Danny to pursue an advanced degree in clinical psychology.
Levi Saunders Danny's sickly younger brother.