Karl Rahner’s “world church” turns out to be a church of significant theological and cultural pluralism in which doctrine can sometimes strain to unify disparate elements. This article examines this problem in light of Rahner’s theory of doctrinal development. First, it examines the notion of doctrine itself, suggesting a pliable model inspired by usages of “dogma” in the early church which reflect both teaching and confession of faith. Second, Rahner’s theory of doctrinal development is discussed in light of Newman’s theory. (...) Rahner’s theory shares Newman’s emphasis on “mind” or “faith consciousness.” Although both attend to the historical mediations of revelation, the truth of doctrine remains at an ideational level, an expression of abstract truth. William Lynch’s notion of the imagination of faith and dogma as a poetic embodiment of truth offers an alternative model that accommodates fundamental insights of both Rahner and Newman. Finally, this article discusses how we can find a foundation for coherence amidst a pluralism of interpretations. The ancient regula fidei is invoked. Here, Rahner’s suggestion of short creedal formulae provides a possible modern equivalent. It is also itself an example of doctrinal development appropriate for situations within the world church in which Catholics now find themselves. (shrink)