Dualism is the view that mind and body, or spirit and matter, are fundamentally different kinds of things. In the provided context, it appears primarily as mind-body dualism, with two major historical reference points: Plato in ancient Greek thought and René Descartes in early modern philosophy. Plato distinguished an immortal soul from a mortal body and argued that the soul survives death and undergoes reincarnation. This made the soul something separable from the physical body. Descartes later gave the most influential modern formulation of this position by defining thinking substance (res cogitans) and extended substance (res extensa) as distinct realities. For Descartes, the mind is non-material and can exist independently, whereas the body is mechanical and cannot think.
The context also connects dualism to debates around mind uploading. Dualistic traditions are said to resonate with the idea of separating mind from body and preserving only the mind. In that sense, dualism provides a philosophical background for the question of whether an informationalized mind could exist independently of its biological substrate. At the same time, the context notes opposing views such as Aristotle’s claim that soul and body are inseparable. Dualism therefore functions not only as a historical doctrine but also as part of an ongoing problem: whether consciousness or mind can exist apart from matter.