Dualists

Dualists are those who defend dualism, the view that reality comprises two fundamental kinds of things or properties. In the philosophy of mind, dualism maintains that mental phenomena are not reducible to physical phenomena. There are two broad forms: substance dualism and property dualism. Substantive dualism holds that mind and body are distinct substances; the mind is non-physical and can, in principle, exist independently of the body. Property dualism holds that there is one physical substance but that mental properties—such as consciousness, intentionality, and qualia—are non-physical properties that cannot be reduced to physical properties.

Historically, Cartesian dualism, advanced by René Descartes in the 17th century, is the most influential version. Descartes proposed res cogitans (thinking substance) and res extensa (extended substance) and suggested a causal interaction through the pineal gland, a idea widely rejected today but emblematic of mind–body interaction. In the contemporary era, discussions have shifted toward more nuanced forms, including naturalistic or dual-aspect approaches, where mind and matter are seen as two aspects of a single underlying reality. Philosophers such as David Chalmers have argued for a robust form of naturalistic dualism, while others defend physicalism or alternative frameworks.

The main challenge for dualists is the interaction problem: how can non-physical mental states causally interact with physical brain states? Critics argue that dualism is untenable or unnecessarily metaphysical, favoring materialist accounts. Despite criticisms, dualist perspectives continue to influence debates on consciousness, personal identity, and the hard problem of consciousness.