But, of course, a system has a danger of becoming a prison, and also the danger, when it is built, of moving within itself, of separating itself from reality, of becoming something which is, so to speak, above the reality which it is supposed to describe. Therefore I am not so much interested in the systems as such – with a few exceptions, for instance with relationship to Origen – but I am interested in the power of these systems to express the reality of the Church and its life.

The Church doctrines have been called dogmas, and in former less noble periods of Christian instruction – for instance when I myself was young – the whole thing was called “the history of dogma.” This cannot be done any more. One calls it “history of Christian thought.” But this is only a change in name, because nobody would dare to present a history of Christian thought in the sense of what every theologian in the Christian Church had thought. That would be an ocean of contradictory thoughts. But this series of lectures has a quite different intent: to show you those thoughts which have become accepted expressions of the life of the Church. And this is what the word “dogma” originally meant.

The concept of dogma is one of the things which lie between the Church and the secular world. Most secular people are afraid of the dogmas of the Church, and not only secular people but also members of the churches themselves. “Dogma” is a red cloth waved before the bull in a bull fight: it produces anger, aggressiveness, or in some cases flight, and I think the latter is mostly the case with the “seculars” with respect to the Church.

Why is this so? Because the word has a very interesting history, which you must know. The first step in this history is the use of “dogma” derived from the Greek doxein, “having an opinion”, in the Greek schools of philosophy preceding Christianity. Dogmata are the differentiating doctrines of the different late Greek schools of philosophy, the Academics (from Plato), the Peripatetics (from Aristotle), the Stoics, the Skeptics, the Pythagoreans. Each of these schools had special fundamental doctrines in which they were distinguished from each other, and if somebody wanted to become a member of one of these schools, he had to accept at least the basic presuppositions which distinguish this school from another school.