For a long time, a certain tradition had become synomymous or allied to metaphysics; similar to how say logic is related to metaphysics today, philosophical theology was once allied with metaphysics.
(Christian) Theology is sometimes divided into components comprising an overall system. A rationally worked out worldview, if it is to be considered a worldview at all, must encompass accounts of all aspects of the world in which we inhabit. Some people still these days entetain the notion of a systematic theology, although often some of the studies in theology consist in specific components. I’m no expert in theology by a long shot, but so far as I recall about theology; there are the following components that comprise systematic theology:
1. Morality and ethics, Value Theory
2. Metaphysics (or ‘Philosophical theology’)
3. Politics (a notable example of this would be Liberation theology)
4. Reactions to contemporary movements: political and social theory, gender theory, psychoanalysis, race and ethnicity studies
5. Christology (the conception of Jesus – the sole figure in the Christian faith, issues such as ‘was Christ a man or God?’, is God in three parts?)
6. Sotierology (concerning ‘grace’ and salvation)
7. Eschatology (concerning the end of days)
There are other aspects which come about but aren’t worth mentioning (like angelogy).
Lately, from the perspective from theology, philosopher-theologians have seen the appeal of analytic philosophy being spliced into their philosophical system. The motivations for this are:
a. Mainstream theology is being hjacked by ‘fringe’ and ‘fashionable’ and short-lived movements. Feminism was a major interest about 2-3 decades ago but since has faded; Black and Asian theology is something which has begun to recieve attention; postmodernism and theology has also been considered. Theology, in a struggle to maintain relevance and establishing some kind of ‘cutting edge’, is failing to establish the kind of clarity and logical rigour had by the likes of Aquinas, or Barth.
b. Theology has been hijacked by continental theology which has led to a confused and needlessly polemical discipline dividing into an intellectual excercise. THere seems to be a serious division between apologetics (by the evangelicals) and theology (by the liberal, intellectual side of Christendom).
c. IT has been demonstrated by the work of people like Alston, Van Inwagen and Swinburne, that the tools of recent philosophy can be employed in the defence and clarification of their notion of God. In other words, theology can be returned to philosophy, rather than living on the outskirts of the humanities and social sciences (continental philosophy for short).
How am I to consider what kind of agenda philosophical theology would entertain? I am not sure, but I am going to start on the Summa Theologica some time soon.