Functionalism (philosophy of mind) in the context of "Mental state"

A mental state, or a mental property, is a state of mind of a person. Mental states comprise a diverse class, including perception, pain/pleasure experience, belief, desire, intention, emotion, and memory. There is controversy concerning the exact definition of the term. According to epistemic approaches, the essential mark of mental states is that their subject has privileged epistemic access while others can only infer their existence from outward signs. Consciousness-based approaches hold that all mental states are either conscious themselves or stand in the right relation to conscious states. Intentionality-based approaches, on the other hand, see the power of minds to refer to objects and represent the world as the mark of the mental. According to functionalist approaches, mental states are defined in terms of their role in the causal network independent of their intrinsic properties. Some philosophers deny all the aforementioned approaches by holding that the term "mental" refers to a cluster of loosely related ideas without an underlying unifying feature shared by all. Various overlapping classifications of mental states have been proposed. Important distinctions group mental phenomena together according to whether they are sensory, propositional, intentional, conscious or occurrent. Sensory states involve sense impressions like visual perceptions or bodily pains. Propositional attitudes, like beliefs and desires, are relations a subject has to a proposition. The characteristic of intentional states is that they refer to or are about objects or states of affairs. Conscious states are part of the phenomenal experience while occurrent states are causally efficacious within the owner's mind, with or without consciousness. An influential classification of mental states is due to Franz Brentano, who argues that there are only three basic kinds: presentations, judgments, and phenomena of love and hate.

Mental states are usually contrasted with physical or material aspects. For (non-eliminative) physicalists, they are a kind of high-level property that can be understood in terms of fine-grained neural activity. Property dualists, on the other hand, claim that no such reductive explanation is possible. Eliminativists may reject the existence of mental properties, or at least of those corresponding to folk psychological categories such as thought and memory. Mental states play an important role in various fields, including philosophy of mind, epistemology and cognitive science. In psychology, the term is used not just to refer to the individual mental states listed above but also to a more global assessment of a person's mental health.

The mind–body problem is a philosophical problem concerning the relationship between thought and consciousness in the human mind and body. It addresses the nature of consciousness, mental states, and their relation to the physical brain and nervous system. The problem centers on understanding how immaterial thoughts and feelings can interact with the material world, or whether they are ultimately physical phenomena.

This problem has been a central issue in philosophy of mind since the 17th century, particularly following René Descartes' formulation of dualism, which proposes that mind and body are fundamentally distinct substances. Other major philosophical positions include monism, which encompasses physicalism (everything is ultimately physical) and idealism (everything is ultimately mental). More recent approaches include functionalism, property dualism, and various non-reductive theories.

Hilary Whitehall Putnam (/ˈpʌtnəm/; July 31, 1926 – March 13, 2016) was an American philosopher, mathematician, computer scientist, and figure in analytic philosophy in the second half of the 20th century. He contributed to the studies of philosophy of mind, philosophy of language, philosophy of mathematics, and philosophy of science. Outside philosophy, Putnam contributed to mathematics and computer science. Together with Martin Davis he developed the Davis–Putnam algorithm for the Boolean satisfiability problem and he helped demonstrate the unsolvability of Hilbert's tenth problem.

Putnam applied equal scrutiny to his own philosophical positions as to those of others, subjecting each position to rigorous analysis until he exposed its flaws. As a result, he acquired a reputation for frequently changing his positions. In philosophy of mind, Putnam argued against the type-identity of mental and physical states based on his hypothesis of the multiple realizability of the mental, and for the concept of functionalism, an influential theory regarding the mind–body problem. Putnam also originated the computational theory of mind. In philosophy of language, along with Saul Kripke and others, he developed the causal theory of reference, and formulated an original theory of meaning, introducing the notion of semantic externalism based on a thought experiment called Twin Earth.

In philosophy of mind, the computational theory of mind (CTM), also known as computationalism, is a family of views that hold that the human mind is an information processing system and that cognition and consciousness together are a form of computation. It is closely related to functionalism, a broader theory that defines mental states by what they do rather than what they are made of.

In cognitive psychology, information processing is an approach to the goal of understanding human thinking that treats cognition as essentially computational in nature, with the mind being the software and the brain being the hardware. It arose in the 1940s and 1950s, after World War II. The information processing approach in psychology is closely allied to the computational theory of mind in philosophy; it is also related to cognitivism in psychology and functionalism in philosophy.

David Malet Armstrong AO FAHA (8 July 1926 – 13 May 2014), often D. M. Armstrong, was an Australian philosopher. He is well known for his work on metaphysics and the philosophy of mind, and for his defence of a factualist ontology, a functionalist theory of the mind, an externalist epistemology, and a necessitarian conception of the laws of nature.

Keith Campbell said that Armstrong's contributions to metaphysics and epistemology "helped to shape philosophy's agenda and terms of debate", and that Armstrong's work "always concerned to elaborate and defend a philosophy which is ontically economical, synoptic, and compatibly continuous with established results in the natural sciences".

In the philosophy of mind, multiple realizability is the thesis that the same mental property, state, or event can be implemented by different physical properties, states, or events.

Philosophers of mind have used multiple realizability to argue that mental states are not the same as—and cannot be reduced to—physical states. They have also used it to defend or criticize many versions of functionalism, especially machine-state functionalism.