Humanist prejudice famously made medieval angelology the paradigm of ludicrous speculation with its caricature of "How many angels can dance on the head of a pin?" The truth is quite the opposite: many of medieval philosophy's most original and ingenious contributions actually came to light in discussions of angelology. In fact, angelology provided an ideal context for discussing issues such as the structure of the universe, the metaphysical texture of creatures (e.g. esse-essentia composition and the principle of individuation), and theories of time, knowledge, freedom, and...