Chapter 11 — Part I: The Creed — Article IX: The Holy Catholic Church; the Communion of Saints
Section 9. Moreover, the end of this vocation, that is, the knowledge and possession of things eternal will be at once understood if we but remember why the faithful of the Old Law were called a Synagogue, that is, a flock for, as St. Augustine teaches, they were so called, because, like cattle, which are wont to herd together. they looked only to terrestrial and transitory goods. Wherefore, the Christian people are justly called, not a Synagogue, but a Church, because, despising earthly and passing things, they pursue only things heavenly and eternal.