ר׳ שלמה בן אברהם אבן אדרת

ר׳ שלמה בן אברהם אבן אדרת (1235–1310), universally known as הרשב״א, was the dominant Catalan halakhist of his generation. Born into a prosperous Barcelona family, he studied Talmud with ר׳ יונה גירונדי and also received the teaching of ר׳ משה בן נחמן and ר׳ יצחק בן אברהם. He combined commercial activity with scholarship before serving for decades as rabbi and communal leader of Barcelona. Questions reached him from Iberia, Provence, France, Germany, Italy, North Africa and the eastern Mediterranean; the thousands of surviving responsa are an exceptional source for medieval Jewish law and social history. His חידושים interpret numerous Talmudic tractates, while תורת הבית systematizes dietary, purity and household law and עבודת הקודש treats Sabbath and festival observance. He defended Judaism against Christian and Muslim polemicists and intervened in communal disputes. In 1305, responding to renewed conflict over philosophy, he and the Barcelona leadership restricted the study of Greek natural science and metaphysics by the young while explicitly exempting medicine. His synthesis of Sephardic Talmudic analysis and practical halakhah profoundly influenced later codifiers, including ר׳ יוסף קארו.