Adam_Ferziger Adam S. Ferziger is a Jewish historian and author. He is known for his study of Jewish assimilation in the Diaspora, and for documenting the evolving relationship between Orthodox and non-observant Jews.Ferziger is the author of Exclusion and Hierarchy, and co-editor of New Perspectives on the Study of Orthodoxy , with Aviezer Ravitzky and Yosef Salmon.