Colors
I couldn't decide on a way to pick just a few random colors categories, without being too reductive and not doing justice to the rich 'gradient' of ideas through which all these texts are connected.
Thus, the ideas shown span the rainbow and mix in and out of each other. Each of the big three main ideas are the primary colors of light: red, blue, and green. From there, the ideas branch off into intermediate colors depending on how they are situated in context with (or "bleed" into/out of) the rest!
Grey, or the absence of color, shows connections to an overarching text or larger guiding principle that doesn't fit cleanly under one type of sub-color or color grouping. (Although grey texts are mentioned in multiple places, their descriptive bubbles are also connected to the some of the major colored ideas I thought they represented)
Shapes
Circles indicate "big ideas" or concepts from the class
Squares indicate more specific insights that go beyond this
Unshaped text is the smallest level of specificity, and deals with further analysis/insights, textual specifics/details, and/or formal features