Kaplan was the first to systematically argue that Ravina and Rav Ashi were not the redactors of the Talmud, but rather the Savoraim.
In 1906, Kaplan moved to New York and continued his studies at the Rabbi Isaac Elchanan Theological Seminary.
[1][5] After briefly serving in rabbinical positions in Glen Cove, NY and Bradford, PA, in 1917, Kaplan became an instructor of Talmud at the Mizrachi Teachers Institute,[2] which was eventually merged into Yeshiva College by Rabbi Meir Bar-Ilan.
[6] Kaplan returned to Columbia University for his PhD and, in 1932, he completed his dissertation, "The Redaction of the Babylonian Talmud," under the supervision of Richard Gottheil.
[8] While originally rejected by scholars such as Boaz Cohen[5] (or considered only one possibility by Gedaliah Alon),[9] Kaplan's thesis of the post-Amoraic redaction of the Babylonian Talmud has been further argued in the work of Hyman Klein, Abraham Weiss, Shamma Friedman, and David Weiss Halivni.