Mortimer J. Adler's conversion to Christianity at age 82 represented far more than a personal spiritual choice - it exemplified a broader pattern of Jewish intellectual apostasy in twentieth-century America. Analysis of Adler's autobiographies and religious writings reveals a decades-long philosophical trajectory shaped by Thomistic thought, beginning in his twenties and intensifying during his "Thomistic Period" (1938-1945) when several of his students converted to Catholicism. Through biographical and textual analysis, a striking pattern emerges: Adler systematically rejected Jewish sources and traditions while displaying minimal engagement with Jewish texts and thought, instead relying on stereotypical characterizations of Judaism alongside deep knowledge of Christian philosophical traditions. His influence on Jewish students' conversions to Christianity, combined with his later theological writings advocating religious "disputations," reflected a profound disconnection from Jewish historical experience and contemporary reality. This disconnection illuminates a larger phenomenon in American Jewish intellectual life where academic philosophical pursuits become increasingly detached from Jewish cultural and religious identity, often leading to assimilation through intellectual rather than purely social channels.