This recently occured to me, and I am a fool for just spilling it out on the net and not writing an article for some famous periodical on it.
I now why Tillich fell out of favour. It's David Tracy's fault.
See, every time I see a reference to correlation in theology these days, I always have the same feeling that there is something wrong. I always feel that what the writer is criticising has little resemblance to what Tillich intended with his correlation method.
Let me first describe what I feel is the usual notion of what the method of correlation does, then describe what Tillich really meant, and finally describe how this is the fault of poor Tracy.
It may all be down to a poor choice of term (English, as you know, was not one of Tillich's strengths). Usually people think that when using a correlation method in Theology you seek for similarities in the Christian tradition on the one hand, and for example (secular) philosophy on the other. In effect you would be saying something like "The Christian doctrine of sin is the same as Heidegger's notion of guilt". This method is correctly criticised for in effect using semi-religious language to re-tell the secular story.
However, this was not what Tillich meant with the method of correlation. For Tillich the point is to use philosophy, psychology, art and similar discourses to describe relevant questions in the present cultural situation. Theology then seeks to give answers to these questions, based on revelation (scripture, tradition and so on). Interestingly a few decades ago this idea was considered to be to give theology a to great role, believing that theology could actually provide answers to common human problems. Wouldn't it be better to just let Theology deal with religious problems?
I guess this is one of the reasons Tracy developed Tillichs method by adding the idea of the hermeneutic circle. No longer would Theology give answers to problems in the human situation but there would be a going back and forth where theology and the situation would interpret each other. This, however, seems to lead to a situation where theology looses its right to interpret itself by its own rules, which is what the method is usually criticised for.
Of course, Tracy is not completely wrong. What he describes does take place. But it is not a method for theology. What he describes is something that has to do with being a theologian, which is a slight but important difference.
Tillich's point was that Theology always has used the method of correlation and always will. And I still can't see how it could be otherwise if theology want to be relevant in any way. So, case in point. In the introduction of "Radical Orthodoxy - a New Theology" we read:
The present collection of essayes attempts to reclaim the world by situating its concerns and activities within a theological framework. Not simply returning in nostalgia to the premodern, it visits sites in which secularism has invested heavily - aesthetics, politics, sex, the body, personhood, visibility, space - and resituates them from a Christian standpoint; that is in terms of the Trinity, Christology, the Church and the Eucharist.
This is exactly what Tillich meant with correlation, to address concerns in the present world from a theological standpoint. Clearly, depending on what questions are asked, different aspects of the Christian tradition will be emphasized, but the fact that Tillich would put the focus on creation and salvation rather than Trinity and Christology is more down to him being Lutheran and not a (roman/anglo) catholic in an age where that mattered.