Paul Johannes Tillich (; German: [‘tIlIx]; August 20, 1886 – October 22, 1965) was a German-American Christian existentialist philosopher, Christian socialist, and Lutheran theologian who was one of the most influential theologians of the twentieth century. Tillich taught at German universities before immigrating to the United States in 1933, where he taught at Union Theological Seminary, Harvard University, and the University of Chicago.
For the general public, Tillich wrote the well-received The Courage to Be (1952) and Dynamics of Faith (1957). His major three-volume Systematic Theology (1951-1963) was for theologians; in many points it was an answer to existentialist critique of Christianity.
Tillich’s work attracted scholarship from other influential thinkers like Karl Barth, Reinhold Niebuhr, H. Richard Niebuhr, George Lindbeck, Erich Przywara, James Luther Adams, Avery Cardinal Dulles, Dietrich Bonhoeffer, Sallie McFague, Richard John Neuhaus, David Novak, Thomas Merton, Michael Novak, and Martin Luther King Jr. According to H. Richard Niebuhr, “[t]he reading of Systematic Theology can be a great voyage of discovery into a rich and deep, and inclusive and yet elaborated, vision and understanding of human life in the presence of the mystery of God.” John Herman Randall Jr. lauded the Systematic Theology as “beyond doubt the richest, most suggestive, and most challenging philosophical theology our day has produced.”
Tillich also authored many works in ethics, the philosophy of history, and comparative religion. His ideas continue to be studied and discussed at international conferences and seminars.