The Discarded Image is a series of lectures, later collected for print, in which C. S. Lewis told of the Medieval worldview, or the System, as he calls it, and its effect on literature of the time (and a bit afterwards - Dante features as an example). Very useful.
Some of the tropes discussed in this book:
- All Myths Are True: Not true per se (you don't actually believe in Hermes and Athena, do you?), but the medievals tended to believe what they read, and what they had to read was eclectic.
- But I Read a Book About It: Lewis explains that in the Middle Ages there were no textbooks - bestiaries are not meant to teach about how animals actually behave, but how men ought, with a heavy dose of literary tradition that was chic to know. Same goes for maps and many other medieval writings. If you wanted a practical skill, you had to learn it from someone.
- Dreaming the Truth: If a medieval work contains a dream sequence, the dream will likely be of this sort.
- Earth Is the Center of the Universe: Erm, yes and no. In the material order of things, sure. But in the spiritual order Earth is sort of the suburbs. (See The Space Trilogy for a literary depiction)
- Epic Catalogue: The medievals loved catalogues of any sort, not always in epic poetry.
- The Fair Folk: Lewis mentions several medieval theories on what, exactly, they are.
- Four-Temperament Ensemble: The four temperaments are discussed in some detail, part of the definition of temperament being how the person handles anger. For instance, if you're an eleven year old and see your friend being bullied, you:
- push the bully away, calling him some choice words, then focus on comforting your friend if you're Sanguine,
- launch yourself at the bully with full intention of breaking nose if you're Choleric,
- fret and obsess over what you should do, feel guilty about not doing it, possibly daydream later on about delivering an epic "The Reason You Suck" Speech if you're Melancholic,
- hang quietly in the background and help your friend clean themselves up later, while lending a sympathetic ear if you're Phlegmatic.
- Shout-Out: Since medieval culture was such a bookish one, these abounded.
- Western Zodiac: Astrology is also discussed, insomuch as it features in literature.