Catholicity

Catholicity, from the Greek katholikos meaning universal, denotes the quality of being universal or whole. In Christian ecclesiology, catholicity describes the universal scope, faith, and mission of the Church—its unity across places and ages, its continuity with apostolic teaching, and its obligation to proclaim the Gospel to all people.

In traditional confessional usage, catholicity is one of the four marks of the Church summarized in the Nicene Creed: one, holy, catholic, and apostolic. The term thus expresses not only doctrinal fullness but also the Church's universality and apostolic succession.

Historically, early Christian writers used catholicity to refer to the Church's universal reach and its fidelity to the apostolic faith. Irenaeus argued that the Church is catholic because it preserves the faith throughout the world and across generations.

Different Christian traditions discuss catholicity with varying emphasis. The term often names the universal Church rather than a single institution; for many in the Orthodox and Protestant contexts it signals universality of the gospel. In Roman Catholic usage, catholicity is linked to the Church's unity under the Church's hierarchy and its fullness of means of salvation.

In contemporary theology, catholicity remains a focal point in ecumenical dialogue, liturgy, and doctrinal formulations that seek to articulate the Church's universal mission while recognizing local particular churches and shared doctrine.