Thesis advisor: Marilee Ogren / The suggestion of a mind-brain duality that emerges out of Descartes’ cogito argument is assessed in the context of twenty-first century neuroscience. The Cartesian texts are explored in order to qualify the extent to which the cogito necessitates such dualism and the functions that Descartes attributes to a non-corporeal soul are precisely defined. The relationship between the mind and brain is explored in the context of a number neuroscientific phenomena, including sensory perception, blindsight, amusia, phantom limb syndrome, frontal lobe lesions, and the neurodevelopmental disorder Williams syndrome, with an attempt to illuminate the physiological basis for each. Juxtaposing the two perspectives, the author concludes that Descartes hypothesis of a disembodied soul is no longer necessary and that a purely physiological understanding of the human mind is now possible, and that there is an underlying affinity between this assertion and Descartes theory of mind. / Thesis (BS) — Boston College, 2009. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: College Honors Program. / Discipline: Psychology.