ר׳ אריה משה אליהו קפלן

ר׳ אריה משה אליהו קפלן (1934–1983), born Leonard Martin Kaplan in the Bronx, was an American Orthodox rabbi, physicist, translator and exceptionally prolific popularizer of Judaism. After a largely secular childhood he entered Torah Vodaath, then studied at the Mir Yeshiva in Jerusalem and received ordination from ר׳ אליעזר יהודה פינקל. Returning to the United States, he earned degrees in physics at the University of Louisville and University of Maryland and conducted magnetohydrodynamics research at the National Bureau of Standards. He subsequently served congregations in Iowa, Tennessee and New York before devoting himself increasingly to writing, editing and youth education. Working with the Orthodox Union and NCSY, he produced lucid introductions to Jewish belief and practice that became influential in the baal-teshuvah movement. His annotated The Living Torah combined translation with archaeological, linguistic and rabbinic material. He also translated and interpreted ספר יצירה, ספר הבהיר, דרך ה׳ and other classics, and restored meditation to serious discussion within Orthodox Jewish spirituality. He died suddenly in Brooklyn at forty-eight and was buried on the Mount of Olives. Several major works appeared posthumously from completed manuscripts and edited lectures.