functionalism
In plain wordsThe view that minds are defined by how they work, not what they are made of: pain, for example, is whatever inner state plays pain's part, linking injury, other thoughts and behavior.
The theory in philosophy of mind that mental states are individuated by their causal roles — the conditions that typically produce them, the effects they typically have and their interactions with other mental states — and not by the stuff that realizes them. To be in pain, on this view, is to be in a state with pain's profile of causes and effects, one brought on by bodily damage, issuing in distress and avoidance and meshing appropriately with beliefs and desires, whether that state occurs in a human brain, an octopus or a machine. Functionalism motivates multiple realizabilitymultiple realizability, n.: The idea that the same mental state, such as pain, could be produced by very different physical systems — human brains, octopus brains or perhaps computers — just as one program can run on different machines. and underlies the computational theory of mindcomputational theory of mind, n.: The idea that thinking is a kind of computation: the mind processes information by following rules, much as a computer runs a program, and the brain is the machine doing it.. Computational functionalism, the version holding that implementing the right computations suffices for consciousness, is the working hypothesis of influential assessments of machine consciousnessmachine consciousness, n.: Whether a machine such as an AI system could have genuine experiences of its own — and the research field that tries to find out, or to build such a machine., such as the 2023 report on indicator properties of consciousnessindicator properties of consciousness, n.: A checklist of design features that leading scientific theories link to consciousness, used to judge how likely it is that a particular AI system could be conscious.. Critics argue that function leaves something out, citing qualiaqualia, n.: The individual felt qualities of experience — the particular redness of red, the taste of mint, the sting of a burn — that seem impossible to capture fully in words. and absent-qualia cases, the Chinese roomChinese room, n.: A thought experiment: a person who knows no Chinese follows a rulebook to answer Chinese messages so well that outsiders think they understand. If the person doesn't understand, does a computer running a program? and BlockheadBlockhead, n.: An imagined machine that passes any conversation test by looking up prewritten replies in an unimaginably huge table. Most people judge it unintelligent, which suggests that behavior alone does not prove intelligence..
If computational functionalism is true, the question is not what the model is made of but which computations it performs.
Origin
Hilary Putnam proposed machine-state functionalism in 'Minds and Machines' (1960) and 'Psychological Predicates' (1967), comparing mental states to the states of a Turing machine. Jerry Fodor, David Armstrong and David Lewis developed other versions in the 1960s and 1970s, and functionalism became the dominant view in philosophy of mind and cognitive sciencecognitive science, n.: The scientific study of how minds work — how we reason, use language, remember and see — combining psychology, neuroscience, linguistics, philosophy, anthropology and artificial intelligence..
Usage note
Not to be confused with functionalism in sociology, linguistics or architecture. Functionalism is usually paired with physicalism but does not strictly entail it, since a functional role could in principle be filled by something nonphysical.
Related
- multiple realizabilitymultiple realizability, n.: The idea that the same mental state, such as pain, could be produced by very different physical systems — human brains, octopus brains or perhaps computers — just as one program can run on different machines.
- computational theory of mindcomputational theory of mind, n.: The idea that thinking is a kind of computation: the mind processes information by following rules, much as a computer runs a program, and the brain is the machine doing it.
- substrate independencesubstrate independence, n.: The idea that a mind depends only on the pattern of information processing, not on the material doing it, so a mind could in principle run on silicon as well as on neurons.
- mind–body problemmind–body problem, n.: The age-old question of how the mind — thoughts, feelings, experiences — relates to the physical body and brain. Is the mind simply what the brain does, or something more?
- machine consciousnessmachine consciousness, n.: Whether a machine such as an AI system could have genuine experiences of its own — and the research field that tries to find out, or to build such a machine.
- Chinese roomChinese room, n.: A thought experiment: a person who knows no Chinese follows a rulebook to answer Chinese messages so well that outsiders think they understand. If the person doesn't understand, does a computer running a program?
- biological naturalismbiological naturalism, n.: John Searle's view that consciousness is a real biological product of brains, as digestion is of stomachs, so running a computer program would not by itself create a mind.
Sources
- Putnam, H. (1967). Psychological Predicates. In W. H. Capitan & D. D. Merrill (eds.), Art, Mind, and Religion. University of Pittsburgh Press. Reprinted as 'The Nature of Mental States'.
Mentioned in
consciousnessconsciousness, n.: Having experiences: there being something it feels like to be you, as when you see red or feel pain. Whether any AI is or could become conscious is an open and fiercely debated question., computational theory of mindcomputational theory of mind, n.: The idea that thinking is a kind of computation: the mind processes information by following rules, much as a computer runs a program, and the brain is the machine doing it., integrated information theoryintegrated information theory, n.: A scientific theory that measures consciousness by how much a system works as a single, unified whole rather than as separate parts. It implies that ordinary computers, whatever software they run, have little or no consciousness., machine consciousnessmachine consciousness, n.: Whether a machine such as an AI system could have genuine experiences of its own — and the research field that tries to find out, or to build such a machine., mind–body problemmind–body problem, n.: The age-old question of how the mind — thoughts, feelings, experiences — relates to the physical body and brain. Is the mind simply what the brain does, or something more?, philosophical zombiephilosophical zombie, n.: An imagined being that behaves exactly like a person — talking, laughing, even saying it feels pain — but has no inner experience at all. Philosophers use it to ask whether behavior proves a mind., philosophy of artificial intelligencephilosophy of artificial intelligence, n.: The branch of philosophy that asks what AI is and could be: whether machines can think, understand or be conscious, what intelligence is, and what we owe to and should expect from intelligent machines., qualiaqualia, n.: The individual felt qualities of experience — the particular redness of red, the taste of mint, the sting of a burn — that seem impossible to capture fully in words., theory of mindtheory of mind, n.: Being able to work out what someone else believes, wants or knows — even when it is not what you believe — and to use that to guess what they will do next. Researchers test whether AI has it., behaviorismbehaviorism, n.: The view that the mind should be studied, or even defined, only through observable behavior rather than inner thoughts or feelings. It shapes debates about whether AI that acts intelligently really is intelligent., biological naturalismbiological naturalism, n.: John Searle's view that consciousness is a real biological product of brains, as digestion is of stomachs, so running a computer program would not by itself create a mind., illusionismillusionism, n.: The view that the inner glow of experience that seems so hard to explain is a kind of trick the brain plays on itself: we are conscious, but not in the mysterious way it seems., indicator properties of consciousnessindicator properties of consciousness, n.: A checklist of design features that leading scientific theories link to consciousness, used to judge how likely it is that a particular AI system could be conscious., Jerry FodorJerry Fodor, prop. n.: An American philosopher who argued that thinking is computation in an inner 'language of thought', and that neural networks cannot explain the structured nature of thought., multiple realizabilitymultiple realizability, n.: The idea that the same mental state, such as pain, could be produced by very different physical systems — human brains, octopus brains or perhaps computers — just as one program can run on different machines., Ned BlockNed Block, prop. n.: An American philosopher who distinguished felt experience from information available for thinking, and who imagined a lookup-table machine to show that passing a conversation test need not mean intelligence., substrate independencesubstrate independence, n.: The idea that a mind depends only on the pattern of information processing, not on the material doing it, so a mind could in principle run on silicon as well as on neurons.