Paul Tillich, German-American philosopher and theologian (d. 1965)
Paul Johannes Tillich (August 20, 1886 – October 22, 1965) was a German-American Christian existentialist philosopher and Lutheran Protestant theologian who is widely regarded as one of the most influential theologians of the twentieth century. Tillich taught at a number of universities in Germany before immigrating to the United States in 1933, where he taught at Union Theological Seminary, Harvard Divinity School, and the University of Chicago.

Among the general public, Tillich is best known for his works The Courage to Be (1952) and Dynamics of Faith (1957), which introduced issues of theology and culture to a general readership. In academic theology, he is best known for his major three-volume work Systematic Theology (1951–63), in which he developed his "method of correlation", an approach that explores the symbols of Christian revelation as answers to the problems of human existence raised by contemporary existential analysis. Unlike mainstream interpretations of existentialism which emphasized the priority of existence over essence, Tillich considered existentialism "possible only as an element in a larger whole, as an element in a vision of the structure of being in its created goodness, and then as a description of man's existence within that framework."Tillich's unique integration of essentialism and existentialism, as well as his sustained engagement with ontology in the Systematic Theology and other works, has attracted scholarship from a variety of influential thinkers including Karl Barth, Reinhold Niebuhr, H. Richard Niebuhr, George Lindbeck, Erich Przywara, Langdon Gilkey, James Luther Adams, Avery Cardinal Dulles, Dietrich Bonhoeffer, Sallie McFague, Richard John Neuhaus, David Novak, John D. Caputo, Thomas Merton, Robert W. Jenson, Thomas F. O'Meara, 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."In addition to Tillich's work in theology, he also authored many works in ethics, the philosophy of history, and comparative religion. Tillich's work continues to be studied and discussed around the world, and the North American Paul Tillich Society, Deutsche Paul-Tillich-Gesellschaft, and l'Association Paul Tillich d'expression française regularly host international conferences and seminars on his thought and its possibilities.