Book IV. 160   ———————————— Argument—In this book it is proved that the extent and long duration of the Roman empire is to be ascribed, not to Jove or the gods of the heathen, to whom individually scarce even single things and the very basest functions were believed to be entrusted, but to the one true God, the author of felicity, by whose power and judgment earthly kingdoms are founded and maintained. 160     In Augustin’s letter to Evodius (169), which was written towards the end of the year 415, he mentions that this fourth book and the following one were begun and finished during that same year.