Rabbi Nathansohn was born at Berezhany (Berzan), Galicia (today"s western Ukraine). He was the son of Aryeh Lebush Nathanson, rabbi at Berzan and author of "Bet El." He studied Talmud at Lviv (Lemberg) together with his brother-in-law Mordecai Zeeb Ettinger.
In the 1830s in Lemberg—then under the rule of the Austrian Empire—he founded an informal study-group under his tutelage. This “yeshiva” attracted some of the most brilliant students in Galicia. In 1857 Nathanson was elected rabbi of Lemberg, where he officiated for eighteen years.
He was a widely recognized rabbinical authority, and was asked to rule on various contemporary issues.
His rulings are still widely cited (for instance he was one of the first to permit the use of machinery in baking Matzah, which created a widespread halachic controversy). Nathanson was very wealthy, and was known for his activity as a philanthropist. he left no children after himself.
He died at Lemberg March 4, 1875.
