The mind-body problem is an ongoing problem in the philosophy of mind and in metaphysics, concerning the nature of the relationship between the mind, or conciousness, and the physical world.

The mind-body problems asks a number of questions: Are the mind and body are separate substances or elements of the same substance? What is their relationship to each other? What is conciousness? And how can conciousness arise out of ordinary matter?

There are a number of responses to the mind-body problem, though none have universal acceptance. A number of these positions are outlined below:

Dualism, the position that the mind is essentially not physical, and exists separately from the body. Dualism comes in various forms:

Interactionism, which states that the mind and body have causal interaction.

Occasionalism, which states the apparently causal links between mind and body are actually divine intervention.

Parallelism, which states that the apparent causal link between mind and body is an illusion, and that mind and body run parallel to one another.

Property dualism, which holds that the mind emerges from the body, and obtains status as something separate.

Monism, the position that the mind and body are not fundamentally separate. There are several types of mind-body monism:

Physicalism, including most commonly-held positions today, which asserts that the mind may be reduced to the physical processes of the brain.

Behaviourism, which holds that talk about mental states can be reduced to talk about behaviours.

Functionalism, which states that mental states are caused by behaviours, senses and other mental states.

Type physicalism, which argues that mental states are equivalent to brain states.

Idealism, which claims that the mind is all that exists.

Phenomenalism, which reduces the physical world to perceptions which exist within the mind alone.

The mind-body problem was brought up in antiquity, and can be seen in the works of Plato, though its modern formulation can be credited to René Descartes, who also presents a dualist response.