I never gave Boccaccio's Decameron too much thought: just a bunch of dirty stories from the proto-Renaissance. But lately, after having taught that period of turmoil in Europe that was the 14th century, I'm reconsidering the work. Here's the initial thought (yet to be fleshed out by a bit of reading, research, and retreat from the chaotic landscape that is currently casa de Lasseter); is Boccaccio doing something similar to what Plato is doing in the Republic?
Plato's work is oft considered a repository of philosophic thought, and indeed it is, but I conjecture that Plato is using philosophy as a vehicle for constructing a mythological world (in much the same way that Shakespeare uses murder in Macbeth or Tolkien uses warfare and fantasy in his works). The point is not the philosophy but the structure and underlying principles. For Plato the structure is based on the number 10 (though the divisions, I think, are later imposed explicitly they are implicit in the original text) but more directly on the number (or ratio) of phi - the golden proportion. What Plato seems to be suggesting is that there is a right and a wrong way of thinking and such dualistic thought is based on the relationship of the lesser and the greater to the whole. The ultimate dramatic purpose of the work is to aid in the emancipation of his interlocutor, Glaucon, whose materialistic vision of the world borders on despair (Glaucon, after all, is the character that raises the image of Gyges' ring and suggests that everyone with such power would do injustice).
In Decameron there is a structure to the story based on ten as well; Deka meiron means "ten days" - there are ten characters - ten stories a day for a total of 100 stories. The balance between the characters is 3 to 7; not quite the golden proportion, indeed - but suggestive of it. The seven women in the story parallel (most commentators suggest) the Pleiades whilst the three men parallel the triune godhead. Definitely a relation of feminine and masculine and definitely a number ratio that was chosen intentionally. The names of the seven characters (referred to as "the Brigata", "the Brigade") themselves are all fanciful and reflect something of the hidden, or occult, knowledge of Western culture.
Looking just at the first and last story also gives a clue. Just as Athens had suffered plague, warfare, riots, famine, dissolution, death, and corruption on a massive scale by the time Plato was creating his interlocutor, Glaucon, so too had Europe suffered corruption, warfare, famine, climate fluctuation, disease, death and moral disintegration by the time of Boccaccio. The characters have fled into a remote castle to escape the horrors of city life and the plague, much as Socrates has "gone down" into the city at the beginning of the Republic. The stories told by the characters in Decameron to pass the time reflect the stories and myths Plato incorporates into his lively discussion of justice in the Republic. Indeed, in Boccaccio's work it is as if the characters are debating a subject through the use of stories; similar to what Chaucer does in his work "Canterbury Tales". The subject debated in Decameron, though, is never explicitly expressed, but I conjecture it probably has something to do with the awfulness surrounding the characters and their opinion of the divine presence that would allow such awfulness to occur. The fact that the Brigata congregates first at the Basilica of Santa Maria Novella before retiring to Fiesole signifies as well. Not only was this the first great basilica in Florence it represented the power of the Church, the beauty of Renaissance art and artwork, and the presence of the divine in His house. It may even be that their congregating here first signifies their own deaths and the retiring to Fiesole is a passage to the next world.
The first story is about deceiving the whole of society and even God perhaps, just as Gyges does. The main character of the first story lives a life of utter corruption and by a false confession at the end of his life secures a legacy of holiness which proclaims him a saint in the eyes of history, again like Gyges. "And why not?" the author seems to be asking at the outset. "If the promises of the divine god have all failed us why shouldn't we carpe diem? The god, after all, is a fool and idiot, cruel and easily swayed. Let us cuckold him and deal with him as the children of the world deal with one another."
The last story also suggests a path similar to Plato's story. Just as the myth of Er stands as corrective to the myth of Gyges, so too the story of the long-suffering wife seems to stand in contrast to the charlatan saint. In this story the lord who deceives his wife and puts her through the worst of trials (pretending to execute her children, divorcing and degrading her, only to restore everything at the end) reminds us of the divine being in Job. The wife is a parallel to Psyche enduring for Cupid; she represents how the Church and the individual soul ought to act in a time of great travail. Her story reminds us that there is great goodness even in the worst of darkness. The very last story of the ten day sequence leaves the hearers with a sense that the divine is not a charlatan even if his reasons for testing us seem obscure. It encourages endurance and persistence in a justice that transcends the calculating economy of getting our due and it shifts the mythological perspective of our relationship to the divine from cunning slave versus master to loving spouse obedient to a magnanimous bridegroom.
Whether Giovanni Boccaccio had direct access to Plato's Republic I do not yet know. He certainly seems to have had access to the occult system of numbers and thought that informed both the golden era of Athens and the Italy of proto-Renaissance Europe. It is, therefore, plausible that the structure and intent of both works might follow a parallel course.
Moreover, the stories in Decameron, just as the stories in Plato, are not mere entertainment. Instead, like all great literature, they edify, inform, and create the mythological world out of which the characters, and thus the readers of the story, choose and act. Mythology informs life and what we see and read, listen to and talk about changes who we are.
A very good blog devoted to this great work can be found HERE at Behold the Stars.