"There is a general failure in antiquity to make a clear distinction between allegorical expression and allegorical interpretation. What we call ‘allegorical interpretation’ in this context normally takes the form of a claim that an author has expressed himself ‘allegorically’ in a given passage. . . . There is never any suggestion that the goal of the commentator is anything but the elucidation of the intention or meaning (διάνοια) of the author. Neither does the interpreter normally feel compelled to justify his claim that the text under consideration ‘says other things than the obvious. His goal is to find the hidden meanings, the correspondence that carry the thrust of the text beyond the explicit. Once he has asserted their existence, he rarely feels the need to provide a theoretical substructure for his claims. If such a substructure is implied, it is often no more than the idea that a prestigious author is incapable of an incoherent or otherwise unacceptable statement, and that an offensive surface is thus a hint that a secondary meaning lurks behind."
Lamberton, Homer the Theologian: Neoplatonist Allegorical Reading and the Growth of the Epic Tradition, 20.