On Christian Doctrine continues. In this installment, we get some short, easy rules about interpreting specific words and expressions which appear more than once in the Bible. We also learn that it’s safer to interpret a work from passages inside it than by reason.
Now, I know this sounds like “Turn off your brain when reading the Bible!”. But we are reading Augustine here, who never met a syllogism he didn’t like. All he’s saying is that the primary way to understand any literary work is studying the literary work itself, and that includes the Bible.
You might logically argue that Pip in Great Expectations is really Johnny Appleseed. (Pip means seed, right? So oranges, apples, pomegranates, same thing….) But the greater logic would be in recognizing that Dickens is the primary source for understanding Dickens, and that logical argument should draw on Dickens more than on itself if it wants to point to a true interpretation. Only then do you move to outside sources like history, linguistics, other authors of the time, literary journal articles, and “this is what I think; see if it makes sense.”