Michael Harrington works primarily on medievalism in both its Western and Eastern forms. He looks at the genesis of medieval philosophy in Late Antique Neoplatonists such as Iamblichus, Augustine, and Dionysius the Areopagite, and how their texts and practices percolate through a commentary tradition that stretches over the next thousand years. In the field of Chinese philosophy, he looks at how the Song and Ming dynasty Confucians appropriate certain Buddhist and Daoist concepts to form what later Chinese philosopher Hu Shi refers to as a Chinese Middle Ages.