The short answer is that retrieval is a particular way of doing historical theology, largely in its insistence on a certain posture toward the Christian past. In my view, I see retrieval as helpful, precisely because of this posture, despite my dissatisfaction with many instantiations of it.
Recent days and years have seen an increased interest in the idea of theological retrieval. While the interest in this idea has grown lately, the practice has been around for some time. This is nowhere near an exhaustive list, but all of the following projects fall within the broad brush of theological retrieval: Roman Catholic ressourcement, la nouvelle théologie, paleo-orthodoxy, ancient-future Christianity, evangelical Catholicism, Radical Orthodoxy, theological interpretation of Scripture, Evangelical ressourcement, and the New Studies in Dogmatics book series. Even if you are not familiar with any of these names, a short glance around evangelical theology today along with its recent publications would reveal that there is not only an increased interest in theological retrieval but also a growing call for its necessity.
So what is theological retrieval and is it any different than what we think of as church history or historical theology? The short answer is that retrieval is a particular way of doing historical theology, largely in its insistence on a certain posture toward the Christian past. In my view, I see retrieval as helpful, precisely because of this posture, despite my dissatisfaction with many instantiations of it.
To understand the posture, it helps to understand its foil. As the opening paragraph implicitly shows, the assorted incarnations of theological retrieval have major differences. But perhaps the most important general agreement is their pushback against at least two complementary problems: (1) the enlightenment and modern epistemological posture that prioritizes independence and progress along with (2) modern theology’s neglect of the terms, content, and resources of classical Christianity. This modern posture is rather obviously problematic to traditional Christianity as theologians have always been interested in passing on a deposit from the past to the future. These problems are not completely foreign to traditional Christianity, though. I would argue that much of our contemporary Christian culture could be described by individualism, relativism, and a thin understanding of history at best. Retrieval wants to help remedy this.
At this point it may still sound like theological retrieval simply wants to do church history as it has always been done. But more than just wanting to inform about the past, retrieval wants to cultivate a disposition. John Webster points toward the difference when he says that retrieval is an “attitude of mind” toward the Christian past that believes it to be uniquely valuable and necessary for the church in the present.
This call for more historical engagement suggests an understanding of history itself and how history should be done (historiography). There are competing views of historiography that are at play which will determine both if someone will participate and how they will participate in theological retrieval. Not everyone sees or does church history the same way.
This points to an important quandary. On the one hand, should the history of the church be understood essentially as a fall (or irreversible decline) that needs to be recovered from? Or on the other hand, should the history of the church be understood essentially as a consistently rich source that is best approached with deference and expectation? Once you answer this question, more questions follow, but this is the fundamental dichotomy against which theological retrieval is responding.