Does anyone remember the remarkable episode of "Yes, Prime Minister" in which Jim Hacker has to appoint a bishop?  The candidates put to him all seem to be academics and political activists.  Theology, it seems, is the route by which non-believers stay in the church.  None of the candidates has ever actually served as a parish priest.
Unless I am misreading his cv, this seems to be the case with Archbishop Rowan Williams.  Before his first bishopric (Monmouth) he was a theology lecturer at Cambridge, and prior to that at a theological college.
