Allegory in the Middle Ages

As we read Dante's Purgatorio it will be helpful to gain some understanding of how the Bible was interpreted in the Middle Ages. A great deal of the basis for Biblical reading can be found in the works of Augustine and Thomas Aquinas. Much of this turns on the nature of allegory as construed in the Middle Ages.

The Letter to Can Grande allegedly written by Dante (whether it was by him or no, it's generally believed that he'd agree with its tenor) sets forth a contrast between the allegory of the poets, as can be found, for example, in Plato, and the allegory of scripture.

Wikipedia offers a brief summary of Dante's views.

From Dante's letter:

...it may be called "polysemous", that is, of many senses [allegories]. A first sense derives from the letters themselves, and a second from the things signified by the letters. We call the first sense "literal" sense, the second the "allegorical", or "moral" or "anagogical". To clarify this method of treatment, consider this verse: When Israel went out of Egypt, the house of Jacob from a barbarous people: Judea was made his sanctuary, Israel his dominion (Psalm 113). Now if we examine the letters alone, the exodus of the children of Israel from Egypt in the time of Moses is signified; in the allegory, our redemption accomplished through Christ; in the moral sense, the conversion of the soul from the grief and misery of sin to the state of grace; in the anagogical sense, the exodus of the holy soul from slavery of this corruption to the freedom of eternal glory.. they can all be called allegorical.

More on Dante's letter and a detailed look at the typological view of Scripture can be found here.