Constructive comparative ecclesiology is the method used by the Faith and Order Commission in its transdenominational documents. The method aims at characterizations of the Church that are inclusive of as many churches as possible. These interpretations thus represent an existential ecclesial existence that is shared by Christians across the churches. This common existential ecclesial existence can be the basis for partial communions among churches, that is, communions that recognize common ecclesial bonds despite substantial ecclesial differences that prevent full communion. The thesis of this essay, then, is that the usefulness of constructive comparative ecclesiology lies in its encouragement of partial communion among the churches.