Practical theology (PT), as a discipline, takes a great deal of
interest in empirical information. In fact, there is an entire school
of thinking within PT — found mainly in the Netherlands and Germany —
that’s called “Empirical Theology.” Practical theologians, because of
the importance of the groundedness of the discipline, are often
well-versed in a social science, the way James Fowler was in
developmental psychology when he developed his Stages of Faith Development.

(An aside: to all of you pissy commentors, I never said that practical theology was the only
type of theology that is grounded, just that it is the most committed
to being grounded. Contextual theologies like liberation, feminist, and
black theologies surely blur the line between systematics, PT, and
biblical studies.)

Other practical theologians take other disciplines as their dialogue
partners, often social psychology, social theory, and sociology. All of
these are important to the practical theologian who is trying to
determine what’s going on in God’s world.
Thus, we turn to social scientists who specialize in figuring out the
“what’s going on?” question. And more and more, practical theologians
are taking up the instruments of empirical research and gathering data
themselves.

This does lead to two interrelated questions: 1) What is the
practical theologian’s mode of interdisciplinarity? It’s intellectually
dishonest to raid other disciplines for their fruits, especially when
they’re saying what you hope they’ll say. So one must enter humbly and
respectfully into dialogue with a field that is not one’s primary are
of expertise. And 2) Who sets the agenda for theology? It seems odd to
let psychologists or sociologists dictate what we should theologize
about. On the other hand, when a dramatic social change happens (e.g.,
globalization), or something happens in the natural sciences (e.g.,
discovery of the “gay gene”), it does seem incumbent upon theology to
respond. Again, these are not decisions to be entered into lightly.

Ultimately, this is what it means for PT to be “grounded.” It means
that there’s a descriptive moment to PT that does, indeed, set it apart
from other types of theologizing.