Giovanni Boccaccio, Genealogia Deorum Gentilium 1.3
“It is to be understood that there is not one simple meaning to these fictions; rather, this may be called polisenum, that is to say ‘of many meanings.’ The first sense may be considered through the outer surface of the fiction, and this is called the literal sense. Other senses are those which are signified through the surface, and these are said to be allegorical.
To make my point clearer, I will provide an example. Perseus, by a figment of the poetic imagination, was the son of Zeus who killed the Gorgon and then, victorious, flew away into the air. While this is read literally, the historical sense is offered up to us. If one were to search for the moral sense of the tale, it is a depiction of wisdom’s victory over vice and the approach to real virtue. But if we wanted to take the tale allegorically, it signifies the elevation of a pious mind to the celestial heights after it has spurned all worldly pleasures. Further, an anagogical interpretation would have it that the story represents the ascent of Christ to God the Father after overcoming the ruler of this world.
Even though these approaches may be called by different names, they can all be called allegory, as it often happens. The word allegory is derived from the Greek allon, which means alienum or diversum (different or diverse), and on that account, however many interpretations may be diverse in the historical or literal modes, they may all rightly be called allegory. Yet, I hardly have a mind to explain the stories which I present according to all of their particular senses or interpretations, since I imagine that it is enough to explicate one of many different senses, though on occasion perhaps more senses will be brought to the fore.”
sciendum est his fictionibus non esse tantum unicum intellectum, quin imo dici potest potius polisenum, hoc est moltiplicium sensum. Nam sensus primus habetur per corticem, et hic licteralis vocatus est; alii per significata per corticem, et hi allegorici nuncupantur.
Et ut quid velim facilius assummatur, ponemus exemplum. Perseus Iovis filius figmento poetico occidit Gorgonem, et victor evolavit in ethera. Hoc dum legitur per licteram hystorialis sensus prestatur. Si moralis ex hac lictera queritur intellectus, victoria ostenditur prudentis in vicium, et ad virtutem accessio. Allegorice autem si velimus assummere, pie mentis spretis mundanis deliciis ad celestia elevatio designatur. Preterea posset et anagogice dici per fabulam Christi ascensum ad patrem mundi principe superato figurari.
Qui tamen sensus etsi variis nuncupentur nominibus, possunt tamen omnes allegorici appellari, quod ut plurimum fit. Nam allegoria dicitur ab allon, quod alienum latine significat, sive diversum, et ideo quot diversi ab hystoriali seu licterali sint sensu, allegorici possunt, ut dictum est, merito vocitari. Verumtamen non est animus michi secundum omnes sensus enucleare fabulas que sequuntur, cum satis arbitrer unum ex pluribus explicasse, esto aliquando apponentur fortasse plures.