Now this development brought a new synthesis on a much more modest level, on the level of Kant’s division of the world of knowledge from the world of values.
But this synthesis also broke down at the end of the 19th and beginning of the 20th centuries, partly under the impact of inner theological development – here I name my great teacher, Troeltsch; and then some of the theologians of the 19th century, my other great teacher, Martin Kaehler of Halle, from the Pietistic and revivalistic tradition; and then some others. And first of all of course, from the world-historical events which spell the end of centuries of European life, the First and then the Second World War.
Now again, represented by Karl Barth, “the diastisis against the synthesis between Christianity and the modern mind” was real. And we are now in a period in which even in many groups formerly liberal in this country, we find an understanding of the problem of the opposition against the synthesis.
Now when you want to hear now, at the end of this whole lecture, my own answer, then I say : Synthesis never can be avoided, because man is always man and at the same time under God. But he never can be under God in such a way that he ceases to be man. And in order to try a new way beyond the former ways of synthesis, I try what I call the way of correlation, namely to accept all the problems which are involved in self- criticizing humanism – -we call it existentialism, today; it is self-analyzing humanism – -and then, on the other hand, to show that the Christian message is the answer to these questions.
Now that is not synthesis, but it is not diastasis either; it is not identification nor is it separation: it is correlation. And I believe that the whole history of thought as I tried to show it to you, points today in this direction.
Paul Tillich, A History Of Christian Thought – Table of Contents