The article examines the thought of the fifth century theologian, Vincent of Lérins, particularly his claims that there is great progress and development in Christ’s Church, and that this progress and development must be in fundamental continuity with what preceded it (eodem sensu eademque sententia). The author argues that Vincent’s hermeneutical principles have been theologically influential in the past and, properly understood, offer significant insights for an apposite notion of doctrinal development today.