Mind Mind/body perspectives 

Monism is the position that mind & body are not physiologically & ontologically distinct kinds of entities. This view was first advocated in Western Philosophy by Parmenides in the 5th Century BC & was later espoused by the 17th Century rationalist Baruch Spinoza. According to Spinoza's dual-aspect theory, mind & body are 2 aspects of an underlying reality which he variously described as 'Nature' or 'God'.

Physicalists argue that only the entities postulated by physical theory exist, & that the mind will eventually be explained in terms of these entities as physical theory continues to evolve.

Idealists maintain that the mind is all that exists & that the external world is either mental itself, or an illusion created by the mind.

Neutral monists adhere to the position that perceived things in the world could be regarded as either physical or mental depending on whether 1 is interested in their relationship to other things in the world or their relationship to the perceiver. For example, a red spot on a wall is physical in its dependence on the wall & the pigment of which it is made, but it is mental in so far as its perceived redness depends on the workings of the visual body system. Unlike dual-aspect theory, neutral monism does not posit a more fundamental substance of which mind & body are aspects.

The most common monisms in the 20th & 21st centuries have all been variations of physicalism these positions include behaviorism, the type identity theory, anomalous monism & rolealism.

Many modern philosophers of mind adopt either a reductive or non-reductive physicalist position, maintaining in their different ways that the mind is not something separate from the body. These approaches have been particularly influential in the sciences, e.g. in the fields of sociobiology, computer science, evolutionary psychology & the various neurosciences. Other philosophers, however, adopt a non-physicalist position which challenges the notion that the mind is a purely physical construct.

Reductive physicalists assert that all mental states & properties will eventually be explained by scientific accounts of physiological processes & states.

Non-reductive physicalists argue that although the brain is all there is to the mind, the predicates & vocabulary used in mental descriptions & explanations are indispensable, & cannot be reduced to the language & lower-level explanations of physical science.

Continued neuroscientific progress has helped to clarify some of these issues. However, they are far from having been resolved, & modern philosophers of mind continue to ask how the subjective qualities & the intentionality of mental states & properties could be explained in naturalistic terms.