During the council, Rahner accepted the Chair for Christianity and the Philosophy of Religion at the University of Munich and taught there from 1964 to 1967. Subsequently, he was appointed to a chair in dogmatic theology at the Catholic theological faculty of the University of Münster, where he stayed until his retirement in 1971. Rahner then moved to Munich and in 1981 to Innsbruck, where he remained for the next 3 years as an active writer and lecturer, also continuing his active pastoral ministry. He published several volumes (23 total in English) of collected essays for the "Schriften zur Theologie (Theological Investigations)", expanded the "Kleines theologisches Wörterbuch (Theological Dictionary)", co-authored other texts such as "Unity of the Churches: An Actual Possibility" with Heinrich Fries, and in 1976 he completed the long-promised systematic work, "Foundations of Christian Faith".