Regarding dualism, he dismissed the extreme form of dualism that stemmed from such philosophers as Plato (body and soul) and Descartes (mind and matter), as well as the theory of extreme monism and the mind–brain identity theory.
Mengenai dualisme, ia menolak bentuk ekstrem dualisme yang berasal dari filsuf-filsuf seperti Plato (tubuh dan jiwa) dan Descartes (pikiran/budi dan materi), serta teori monisme ekstrem dan teori identitas budi-otak.