Rabbi Yosef Shaul Nathanson—Shoel u-Meshiv רבי יוסף שאול נתנזון — שואל ומשיב

Rabbi Yosef Shaul Nathanson became rabbi of Lemberg in 1857 and held the post for eighteen years; but he was consulted long before that and far beyond the city. He was one of those to whom people write when they do not know whom else to ask.

His responsa—Shoel u-Meshiv, Asker and Answerer—came out in six parts and ran to thousands of answers. The century was new and so were the questions: may one ride a train on Shabbat if it moves by itself; what of machine-made matzah; what of photography, of new medicines, of printed scrolls. He answered quickly and to the point—he was sometimes reproached for speed, never for lightness: every answer stood on sources.

The dispute over machine matzah, where he permitted and Rabbi Shlomo Kluger forbade, is among the most famous of that century, and both books are read side by side.