Mind Philosophy of mind 

Philosophy of mind is the branch of philosophy that studies the nature of the mind, mental events, mental roles, mental properties, consciousness & their relationship to the physical body. The mind-body problem, i.e. the relationship of the mind to the body, is commonly seen as the central issue in philosophy of mind, although there are other issues concerning the nature of the mind that do not involve its relation to the physical body.

Dualism & monism are the 2 major schools of thought that attempt to resolve the mind-body problem. Dualism is the position that mind & body are in some way separate from each other. It could be traced back to Plato, Aristotle & the Samkhya & Yoga schools of Hindu philosophy, but it was most precisely formulated by René Descartes in the 17th century.Substance dualists argue that the mind is an independently existing substance, whereas Property dualists maintain that the mind is a group of independent properties that emerge from & cannot be reduced to the brain, but that it is not a distinct substance.

The 20th century philosopher Martin Heidegger suggested that subjective experience & activity cannot be made sense of in terms of Cartesian 'substances' that bear 'properties' at all . This is because the nature of subjective, qualitative experience is incoherent in terms of – or semantically incommensurable with the concept of – substances that bear properties. This is a fundamentally ontological argument.