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17. Mind and Body / E. Mind as Physical / 2. Reduction of Mind

[all mental events can be explained physically]

22 ideas
You needn't be made of laughing particles to laugh, so why not sensation from senseless seeds? [Lucretius]
     Full Idea: One can laugh without being composed of laughing particles, ..so why cannot the things that we see gifted with sensation be compounded of seeds that are wholly senseless?
     From: Lucretius (On the Nature of the Universe [c.60 BCE], II.988)
     A reaction: Lovely argument! You might feel driven to panpsychism in your desperation to explain the 'weirdness' of consciousness, but it would be mad to attribute laughter to basic matter, so comedy has to 'emerge' at some point.
We could probably, in principle, infer minds from brains, and brains from minds [Russell]
     Full Idea: It seems not improbable that if we had sufficient knowledge we could infer the state of a man's mind from the state of his brain, or the state of his brain from the state of his mind.
     From: Bertrand Russell (The Ultimate Constituents of Matter [1915], p.131)
     A reaction: This strikes me as being a very good summary of the claim that mind is reducible to brain, which is the essence of physicalism. Had he been born a little later, Russell would have taken a harder line with physicalism.
Searle argues that biology explains consciousness, but physics won't explain biology [Searle, by Kriegel/Williford]
     Full Idea: Searle appears to argue that phenomenal consciousness is explained in biological terms, but that biological properties are irreducible to purely (micro)physical ones.
     From: report of John Searle (The Rediscovery of the Mind [1992]) by U Kriegel / K Williford - Intro to 'Self-Representational Consciousness' n1
     A reaction: Searle is very hard to pin down, and this account suggests the reason very clearly - because he is proposing something which is bizarrely implausible. The reduction of biology-to-physics looks much more likely than consciousness-to-biology.
If mind is caused by brain, does this mean mind IS brain? [Searle]
     Full Idea: I hold a view of mind/brain relations that is a form of causal reduction (mental features are caused by biological processes), but does this imply ontological reduction? (…No!)
     From: John Searle (The Rediscovery of the Mind [1992], Ch. 5.II.5)
     A reaction: What exactly is his claim? Presumably 'causal reduction' implies identity of (philosophical) substance. This seems to imply 'emergence' in a rather old-fashioned and dramatic way, though elsewhere Searle denies this.
Can the homunculus fallacy be beaten by recursive decomposition? [Searle]
     Full Idea: The idea (of Dennett and others) is that recursive decomposition will eliminate the homunculi.
     From: John Searle (The Rediscovery of the Mind [1992], Ch. 9.VI)
     A reaction: Lycan is the best exponent of this view, which I like. My brain clearly has a substantial homunculus which I call my PA; it regularly reminds of what I have to do in an hour's time. I am sure it is composed of smaller brain components working as a team.
Is the dependence of the psychological on the physical a priori or a posteriori? [Jackson]
     Full Idea: Should the necessary passage from the physical account of the world to the psychological one that physicalists are committed to, be placed in the a posteriori or the a priori basket?
     From: Frank Jackson (From Metaphysics to Ethics [1998], Ch.3)
     A reaction: That is, is 'the physical entails the mental' empirical or a priori? See Idea 3989. If we can at least dream of substance dualism, it is hard to see how it could be fully a priori. I think I prefer to see it as an inductive explanation.
The core of the puzzle is the bridge laws between mind and brain [Kim]
     Full Idea: From the emergentist point of view, the reductionists bridge laws are precisely what need to be explained. Why do these mental-physical correlations hold?
     From: Jaegwon Kim (Philosophy of Mind [1996], p.229)
     A reaction: Everyone is happy with the bridge laws from chemistry to physics, but no one knows (deep down) why those exact laws hold. We need to understand what consciousness is; its cause will then, I think, become apparent.
Prior to Kripke, the mind-brain identity theory usually claimed that the identity was contingent [Perry]
     Full Idea: Advocates of the mind-body identity theory typically claimed that identity between particular mental states and brain states was contingent, until Kripke argued persuasively that identity is always necessary.
     From: John Perry (Knowledge, Possibility and Consciousness [2001], §8.1)
     A reaction: Kripke wanted to argue against the identity theory, but what he seems to have done is reformulate it into a much more powerful version (involving necessary identity).
I am a reductionist about mind because I am an a priori reductionist about everything [Lewis]
     Full Idea: My reductionism about mind began as part of an a priori reductionism about everything.
     From: David Lewis (Lewis: reduction of mind (on himself) [1994], p.412)
     A reaction: He says this is 'a priori' to avoid giving hostages to fortune, but I think is the best explanation of the total evidence facing us
Intelligent agents are composed of nested homunculi, of decreasing intelligence, ending in machines [Dennett]
     Full Idea: As long as your homunculi are more stupid and ignorant than the intelligent agent they compose, the nesting of homunculi within homunculi can be finite, bottoming out, eventually, with agents so unimpressive they can be replaced by machines.
     From: Daniel C. Dennett (Sweet Dreams [2005], Ch.6)
     A reaction: [Dennett first proposed this in 'Brainstorms' 1978]. This view was developed well by Lycan. I rate it as one of the most illuminating ideas in the modern philosophy of mind. All complex systems (like aeroplanes) have this structure.
Mind-brain reduction is less explanatory, because phenomenal concepts lack causal roles [Papineau]
     Full Idea: Mind-brain reductions are less explanatory than characteristic reductions in other areas of science, ...because phenomenal concepts have no special associations with causal roles.
     From: David Papineau (Thinking about Consciousness [2002], 5.3)
     A reaction: This may always have some truth in it, but I would expect reductive accounts in the far future to get much closer to giving explanations of phenomenal experience. We can't work down from the phenomenal end, but we can work up from the physical/causal end.
Weak reduction of mind is to physical causes; strong reduction is also to physical laws [Papineau]
     Full Idea: Weak reduction of mind requires only that mental causes be identified with physical causes. A strong reduction requires also that the laws by which such causes operate follow by composition from non-special laws.
     From: David Papineau (Thinking about Consciousness [2002], App 3 n8)
     A reaction: I'm cautious about laws, but I still vote for strong reduction. No new principles are needed to make a mind from a brain.
Sensations may be identical to brain events, but complex mental events don't seem to be [Flanagan]
     Full Idea: There is still some hope for something like identity theory for sensations. But almost no one believes that strict identity theory will work for more complex mental states. Strict identity is stronger than type neurophysicalism.
     From: Owen Flanagan (The Really Hard Problem [2007], 3 'Ontology')
     A reaction: It is so hard to express the problem. What needs to be explained? How can one bunch of neurons represent many different things? It's not like computing. That just transfers the data to brains, where the puzzling stuff happens.
'Valence' and 'gene' had to be reduced to show their compatibility with physicalism [Field,H]
     Full Idea: 'Valence' and 'gene' were perfectly clear long before anyone succeeded in reducing them, but it was their reducibility and not their clarity before reduction that showed them to be compatible with physicalism.
     From: Hartry Field (Tarski's Theory of Truth [1972], §5)
We reduce the mind through homuncular groups, described abstractly by purpose [Lycan]
     Full Idea: I am explicating the mental in a reductive way, by reducing mental characterizations to homuncular institutional ones, which are teleological characterizations at various levels of functional abstraction.
     From: William Lycan (Consciousness [1987], 4.3)
     A reaction: I think this is the germ of a very good physicalist account of the mind. More is needed than a mere assertion about what the mind reduces to at the very lowest level; this offers a decent account of the descending stages of reduction.
Teleological functionalism helps us to understand psycho-biological laws [Lycan]
     Full Idea: Teleological functionalism helps us to understand the nature of biological and psychological laws, particularly in the face of Davidsonian scepticism about the latter.
     From: William Lycan (Consciousness [1987], 4.4)
     A reaction: Personally I doubt the existence of psycho-physical laws, but only because of the vast complexity. They would be like the laws of weather. 'Psycho-physical' laws seem to presuppose some sort of dualism.
Reduction of intentionality involving nonexistent objects is impossible, as reduction must be to what is actual [Jacquette]
     Full Idea: If intentionality sometimes involves a relation to nonexistent objects, like my dreamed-of visit to a Greek island, then such thoughts cannot be explained physically or causally, because only actual physical entities and events can be mentioned.
     From: Dale Jacquette (Ontology [2002], Ch.10)
     A reaction: Unimpressive. Thoughts of a Greek island will obviously reduce to memories of islands and Greece and travel brochures. Memory clearly retains past events in the present, and hence past events can be part of the material used in reductive accounts.
Early identity theory talked of mind and brain 'processes', but now the focus is properties [Heil]
     Full Idea: The early identity theorists talked of identifying mental processes with brain processes, but I am now proposing it as a theory about properties.
     From: John Heil (Philosophy of Mind [1998], Ch.3)
     A reaction: Since a process is presumably composed of more basic ontological ingredients, this is presumably a good move, but there is still a vagueness about the whole concept of a 'property'.
Scans of brains doing similar tasks produce very similar patterns of activation [Carter,R]
     Full Idea: The pattern of brain activation during, say, a word retrieval task is usually similar enough among the dozen or so participants who typically take part in such studies for their scans to be overlaid and still show a clear pattern.
     From: Rita Carter (Mapping the Mind [1998], p. 17)
     A reaction: This doesn't surprise me, though it could be interpreted as supporting type-type identity, or as supporting functionalism. Armstrong and Lewis endorse a sort of reductive functionalism which would fit this observation.
Thinking takes place on the upper side of the prefrontal cortex [Carter,R]
     Full Idea: The nuts and bolts of thinking - holding ideas in mind and manipulating them - takes place on the upper side of the prefrontal cortex.
     From: Rita Carter (Mapping the Mind [1998], p.312)
     A reaction: Keep this firmly in view! Imagine that the skull is transparent, and brain activity moves in waves of colour. Dualism would, in those circumstances, never have even occurred to anyone.
We imagine small and large objects scaled to the same size, suggesting a fixed capacity for imagination [Lavers]
     Full Idea: If we think of a pea, and then of the Eiffel Tower, they seem to occupy the same space in our consciousness, suggesting that we scale our images to fit the available hardware, just as computer imagery is limited by the screen and memory available.
     From: Michael Lavers (talk [2003]), quoted by PG - Db (ideas)
     A reaction: Nice point. It is especially good because it reinforces a physicalist view of the mind from introspection, where most other evidence is external observation of brains (as Nietzsche reinforces determinism by introspection).
Studying biology presumes the laws of chemistry, and it could never contradict them [Friend]
     Full Idea: In the hierarchy of reduction, when we investigate questions in biology, we have to assume the laws of chemistry but not of economics. We could never find a law of biology that contradicted something in physics or in chemistry.
     From: Michèle Friend (Introducing the Philosophy of Mathematics [2007], 3.1)
     A reaction: This spells out the idea that there is a direction of dependence between aspects of the world, though we should be cautious of talking about 'levels' (see Idea 7003). We cannot choose the direction in which reduction must go.