Virtue
Each of the 10 main characters values traditional Catholic virtues. These include the four cardinal virtues, the three theological virtues, and also in some theories the Greek conception of the tripartite person: prudence, justice, temperance, fortitude, faith, hope, charity, reason, spirit, and appetite. All 10 of the characters embody one of these virtues, which they bring with them to their interactions with the others as well as the morals of their stories. Amid a time when moral and ethical virtues were tossed aside in the face of suffering, these young people are trying to revive their religion. The general population lost faith in the Catholic church, but Boccaccio uses his pen to write about the few faithful ones who valued virtue over survival. They honorably accept their likely deaths and choose to preserve dignity and faith in the meantime.
Capitalist Values
Boccaccio, writing in 14th Century Italy, clearly understands the shift in cultural values. While the feudal system allowed people to strictly obey the church and to value their own lives through spiritual terms, the emerging metropolitization of Europe made those traditional values nearly impossible to preserve as they had been before. Now industry and capitalism lead people to be valued in society differently. Now they must be industrious, quick-witted, ambitious, etc.
Meta-narrative
Boccaccio is the master of the meta-narrative. He layers story upon story, interweaving many old tales. As an Italian artist, he participates in the model first laid by Dante in his Divine Comedy. Boccaccio nests his stories within grander stories, using much work from his predating authors. Similar to the phenomenon of sampling in hip-hop and rap, he samples classic folktales and the like from various countries in order to enrich his own storytelling. This is what makes him a master of the meta-narrative. He not only includes historical touchstones, but he makes them work for his own ends in the book. Rather than copy and pasting a story verbatim, he twists it into something which suits his meta-narrative as well. This is true for all 100 stories.
