He received ordination at Hebrew Union College in Cincinnati in 1948. After returning to Berlin to serve as rabbi of the Berlin Jewish Community under the auspices of the World Union for Progressive Judaism he met Lily Rose (1913–2009) whom he later married. In 1950 he returned to the United States serving in Temples in Lynn, Massachusetts, where he came into contact with Rabbi Joseph B. Soloveitchik of Boston whom he came to view as an important teacher, and in Fargo, North Dakota. He was a member of both Reform and Conservative rabbinic assemblies.
He edited the journal Judaism-A Quarterly Journal from 1961 until 1969 and was the senior editor of the Werke of Hermann Cohen.
He was awarded an honorary degree by the Hebrew Union College-Jewish Institute of Religion.
Both in person and by correspondence he entered into dialogue with the American Mennonite theologian and pacifistJohn Howard Yoder,[1][2][3] with the American Catholic monk and writer Thomas Merton, and with many leading figures in philosophy and in Jewish thought.
Following Hermann Cohen, Schwarzschild espoused a form of neo-Kantianism and emphasized the role of the halakha in Judaism as a rational system of moral ideals. He was also strongly influenced by Maimonides.
He asserted at the National Interreligious Conference on Peace:
"When God, the Radical, demands that we seek peace, He demands that we radically seek radical peace...not only when it fits into the political plans of our government, nor only when it is socially safe to talk about it, nor yet to the degree to which this seems practically prudent and promising of results, but under the irresistible command of God, always, everywhere, in every way, and totally, religion must insist on, explore, and practice the ways of peace toward the attainment of peace." (Judaism, Fall 1966).
Articles
'The Tragedy of Optimism - Steven Schwarzschild’s Writings on Hermann Cohen', State University NY Press, New York 2018 (George Y. Kohler, ed.)
'The Personal Messiah-Toward the Restoration of a Discarded Doctrine,' (1956), in Kellner, M. (ed.),The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'Franz Rosenzweig and Existentialism,'(1956), in Year Book of the Central Conference of American Rabbis,
'Do Noachites Have to Believe in Revelation? (A Passage in Dispute between Maimonides, Spinoza, Mendelssohn, and Hermann Cohen). A Contribution to a Jewish View of Natural Law,' (1962), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'To Re-Cast Rationalism,' (1962), in Frank, D. Leaman, O. and Manekin, C.H. (ed.), (2000), The Jewish Philosophy Reader, (Cambridge University Press).
'The Lure of Immmanence-The Crisis in Contemporary Religious Thought,' (1967), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'Judaism, Scriptures, and Ecumenism,' (1967), Neusner, J. (ed.), Judaism and Christianity: The New Relationship, (1993), (Garland Pub.)
'On the Theology of Jewish Survival,' (1968), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'A Note on the Nature of Ideal Society-A Rabbinic Study,' in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'The Legal Foundation of Jewish Aesthetics,' (1975), in Kellner, M. (ed.), Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'The Tenability of Herman Cohen's Construction of the Self,' (1975), Journal of the History of Philosophy, Vol. 13, No. 3
'The Question of Jewish Ethics Today,' (1976), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'Moral Radicalism and "Middlingness" in the Ethics of Maimonides,' (1977), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'Jean-Paul Sartre as Jew,' (1983), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'An Introduction to the Thought of R. Isaac Hutner,' Modern Judaism, (1985), Vol. 5, No. 3
'A Critique of Martin Buber's Political Philosophy-An Affectionate Reappraisal,' (1986), in Kellner, M. (ed.),The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'On Jewish Eschatology,' (1986), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'Modern Jewish Philosophy,' (1987), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'Shekhinah and Eschatology,' (1987), in Kellner, M. (ed.), The Pursuit of the Ideal: Jewish Writings of Steven Schwarzschild (1990), (State University of New York Press)
'Adorno and Schoenberg as Jews Between Kant and Hegel,' Leo Baeck Institute Yearbook, (1990), 35
'The Unnatural Jew,' in Yaffe, M.D. (ed), Judaism and Environmental Ethics: A Reader, (2001), (Lexington Books.)
Kellner, Menachem. "Torah and Science in Modern Jewish Thought: Steven Schwarzschild vs. Yeshayahu Leibowitz," Torah et Science: Perspectives historiques et théoriques: études offertes à Charles Touati, Gad Freudenthal, Jean-Pierre Rothschild, and Gilbert Dahan, eds. (Paris: Peeters, 2001), pp. 229–237.
