Contrary to Maurice Wiles’ opinion that Anglicanism has no identifiable content, Philip Turner states that, “the doctrinal content Anglicans share is embedded primarily in liturgical practices the purpose of which is to form the character of a communion of believers. Its liturgical and formational setting means that the doctrinal content of Anglicanism is, as it were, scattered through a complex of practices rather than focused in a specifically theological document.”
Turner is careful here, noting that if one says that the primary focus of Anglicanism is “liturgical practices,” then one is also saying in the same breathe that the heart of Anglican theology is the doctrine of the Holy Trinity. For at the center of the Book of Common Prayer is the “prayer to the Father, through the Son, in the Spirit.”
The complex of liturgical practices that comprise the doctrinal content of Anglicanism is, of course, found in The Book of Common Prayer. And the Catechism at the back of the 1979 Prayer Book offers "a brief summary of the [Episcopal] Church's teaching [i.e., doctrine] for an inquiring stranger who picks up a Prayer Book" (p. 844). I note also that the Prayer Book describes the Catechism as "a commentary on the creeds," which underscores the normative centrality of the doctrinal content of the Apostles' and Nicene Creeds for the Episcopal Church (ibid.).
So even if it's true that, as one bishop and Anglican priest have written, "The Episcopal Church does not readily think in terms of 'doctrine'," that's not because we have no identifiable doctrine. It's right there in the Prayer Book. We corporately enact it every time we gather for the liturgy. And in the Prayer Book's ordination vows, clergy have voluntarily promised "to conform to the doctrine, discipline, and worship of the Episcopal Church" (pp. 513, 526, & 538). That would be a very strange promise to make if we had no identifiable doctrine!