Epstein diligently studied the works of Isaac Baer Levinsohn, Nachman Krochmal, and S. D. Luzzatto, and when he traveled in western Europe for the first time in 1861, he made the acquaintance of J.L. Rapoport, Z. Frankel, and Michael Sachs. After his father's death in 1874 (see Israel Epstein's biography in ''Ha-Shaḥar'', vi.699-708) Epstein took charge of his extensive business interests, but gradually wound up all his affairs, and from 1884 devoted most of his time to travel and study. He settled in Vienna in 1876 and became an Austrian subject. He was the possessor of a large library which contained many valuable manuscripts.
