The "Divine Comedy" was entitled by Dante himself merely "Commedia," meaning a poetic composition in a style intermediate between the sustained nobility of tragedy, and the popular tone of elegy.
"Plutarch's Lives, written at the beginning of the second century A.D., is a social history of the ancient world by one of the greatest biographers and moralists of all time.
"The Six Enneads ... is the collection of writings of Plotinus, edited and compiled by his student Porphyry (c. 270 AD). Plotinus was a student of Ammonius Saccas and they were founders of Neoplatonism.
The book presents lucid descriptions of human mental activity, with detailed considerations of the stream of thought, consciousness, time perception, memory, imagination, emotions, reason, abnormal phenomena, and similar topics.