From the Pope:
"In 1967 we were still able to celebrate brilliantly the 150th anniversary of the creation of the Faculty for Catholic Theology at Tübingen; but this was the last celebration in the old style. At almost a moment's notice, there was a change in the ideological "paradigm" by which the students and a part of the teachers thought...almost overnight the existentialist model collapsed and was replaced by the Marxist...and the Marxist revolution kindled the whole university with its fervor, shaking it to its very foundations. A few years before, one could still have expected the theological faculties to represent a bulwark against the Marxist temptation. Now the opposite was the case: they became its real ideological center."
-Milestones by Joseph Cardinal Ratzinger, pp. 136-137.