Is Functionalism a Convincing Theory of Mind?
I will conclude that functionalism is a highly convincing theory of mind. It successfully overcomes the rigidity of MBTIT via multiple realisability, and remains resilient against intuition-based objections like the Chinese Mind through the logical consistency of functional duplicates
- Functionalism is the view that all mental states are characterised by their functional roles (what they do) rather than their internal composition (what they are made of). A mental state is defined by its inputs (stimuli), its relation to other mental states, and its outputs (behaviour) - Its primary strength is its compatibility with Multiple Realisability: it allows that a human, an octopus, and a computer can all 'be in pain' if they perform the same global function, regardless of their hardware - I will evaluate functionalism against Ned Block's 'Chinese Mind' objection and Jackson's Knowledge Argument. I will argue that functionalism survives both by demonstrating that our intuitions about 'absurdity' are not a reliable guide to metaphysical reality
Section 1: Functionalism and the Strength of Multiple Realisability
- Unlike MBTIT, Functionalism doesn't have to explain why different physical things feel the same; it simply defines the feel as the function. This is parsimonious and logically robust - The only real challenge is the 'biological function' skepticism (e.g., octopuses might feel 'different' pain). However, Putnam’s logically possible alien version bypasses this by showing that even if octopuses *don't* feel pain, something *could* feel pain in a different substrate. This proves that identity must be functional, not just chemical
Hilary Putnam: The Functionalist Definition
- Putnam argues that what makes a mind a mind is its functional organization. Just as a 'mousetrap' isn't defined by being made of wood or metal, but by its function of catching mice, a mind is defined by its ability to process information and produce behavior - This allows for 'Multiple Realisability': mental states like 'pain' can exist in brains, computers, or aliens. What matters is the 'software' (functional role), not the 'hardware' (physical substrate)
Section 2: The Chinese Mind / China Brain Objection
- Block's argument relies entirely on intuition — it just 'feels' wrong that a country could be a mind. But as critics note, it also 'feels' wrong that a bunch of grey neurons could produce a mind. Our intuitions about the emergence of consciousness are universally unreliable - David Chalmers' cybernetic brain thought experiment provides a powerful counter: if we replace neurons one by one with silicon chips, and the function remains identical, it is more plausible to assume consciousness persists than to assume it suddenly 'vanishes' at a certain point. This supports Functionalism over Block's skepticism
Ned Block: The Chinese Mind (Absent Qualia)
- Block imagines the entire population of China (representing neurons) communicating via radios to perform the functional role of a human mind (the China Brain). Hooked up to a robot, this system would act exactly like a person - Block argues that while this system is functionally identical to a mind, it would have no qualitative experience (qualia). It is a 'functional duplicate' that is hollow inside. Therefore, functionalism fails because it cannot account for the internal 'feel' of consciousness
Section 3: The Mary Argument and Functional Facts
- The 'New Knowledge, Old Fact' response applies here just as it does to MBTIT. Mary learns a new 'way' of perceiving a functional state. Seeing red is a 'first-person' way of knowing the functional state of color-processing - Functionalism is actually better positioned than MBTIT to handle Mary because it defines the 'old fact' as a dynamic role rather than a static chemical. Mary already knew the 'role', she just hadn't 'played' it yet. Gaining the experience is simply the system entering that functional state
Frank Jackson: Mary against Functionalism
- If Mary learns all functional facts about color in her room, and then learns what red is like upon leaving, there must be more to red than its functional description. Qualia are properties that cannot be captured by mapping inputs to outputs - Therefore, even a perfect functional account of the mind is incomplete, as it misses the subjective 'what-it-is-likeness' of experience
- Functionalism provides a more flexible and scientifically viable framework for the mind than either dualism or identity theory. By decoupling the mental from the purely biological, it accounts for the diversity of conscious life forms we expect in a complex universe - While the China Brain experiment strains our common-sense intuitions, it fails to show a logical contradiction. Chalmers' 'cybernetic brain' thought experiment suggests that if the function remains constant, consciousness must remain constant too - The Mary argument is handled by the 'New Knowledge, Old Fact' response, showing that 'what it is like' is just a first-person perspective on a functional process. Therefore, functionalism is the most convincing physicalist theory available