Mind's place in nature

This is a response to LaudateAgno's post linked below. I am starting a new thread so that it doesn't get lost. I am grateful to LA for giving me this opportunity to clarify the materialist position. I will deal with the specific points made by LA in his post in some detail. But first, I wish to supply a more precise definition of physicalism than I have attempted hitherto. I will then show how physicalism is consistent with our having reasons for our actions and with our moral responsibility for our actions. I shall say that the world is “causally closed under physical description” iff (if and only if) all events under physical description (that is, described solely in terms of the sorts of categories that figure in the physicist's description – position, mass, charge, etc.) are completely explained by other events under physical description. Physicalism I shall define as the conjunction of two theses: (1) the world is causally closed under physical description, and (2) all events come under some physical description. “Events” I shall take, for the moment, as that of which existence can be affirmed or denied in the primary sense of “existence”. Reasons Can physicalism accommodate acting for reasons? To see that it can, let us take an analogy. Imagine that you are playing chess against a computer. The computer makes a move that prevents its being checkmated by your next move. It is surely true to say that it made the move it did “in order to” prevent itself from being checkmated. This derives from the fact that the computer is so programmed as to analyse all possible outcomes of different moves and select the one that will avoid checkmate. Given that this is the case, we can explain its moves in these terms, in terms of how the computer functions, how it deals with certain inputs to generate certain outputs. It should be noted that this is completely compatible with another kind of explanation for the computer's actions, in terms of the disposition of all the constituent particles of the computer, as well as the disposition of all the particles in its environment. An omniscient scientist with unlimited computational power would be able to accurately predict the precise moves the computer makes from this data alone. Philosophers say that the physical state “realises” the functional state. It is because the computer is in a certain physical state that it handles its data in the way it does. This is a useful analogy, because I assume that no one is going to say that the computer has “free will” or is anything other than a machine. We might properly baulk at the notion that the computer does things for reasons, since it is a very simple machine indeed, and has none of the other attributes we regard as essential for a fully sentient and rational being. Nevertheless, its acting in order to realise certain ends is consistent with it being a completely deterministic system, which is the vital point at issue. If the brain is a completely deterministic system, then this is consistent with its having a vast number of potential functional states depending on its precise structure. These functional states determine how the brain processes inputs in order to achieve some goals and avoid others. We call this doing things for reasons. Moral Responsibility I should say that I am morally responsible for my actions insofar as my actions spring from myself rather than having an external source. If I am compelled to act in a certain way, then my responsibility is thereby lessened or eliminated. To act of my own free will means no more than not to be acting under compulsion. If someone orders me to open the bank vaults at gunpoint, no one blames me for doing this, because I am acting under external compulsion. If I myself open the bank vaults and distribute the money to the poor, then I am blamed for this because the action arises solely from my own personality. Clearly, this is consistent with my personality itself being causally determined. And any other notion of “free will” is scarcely intelligible, and cannot be made coherent (several centuries of philosophers trying have yet to yield anything credible). My actions are the result of my personality, which is itself the outcome of my experiences and congenital factors. Who can doubt this? If I grew up in a different society with different expectations and experiences I would have a quite different personality. If, on the other hand, we say that certain brain impulses just happen miraculously, with no connection to my personality, then how can I be held responsible for the subsequent actions? Only determinism is capable of providing a rational ground for the ascription of responsibility. The muddled metaphysical notion of “free will”, as well as being inconsistent with moral responsibility, is also quite incredible. Are we seriously to believe that physical particles obey physical laws everywhere in the universe, except in human craniums, where the laws of nature are constantly broken and everything happens by a miracle? And if we do suppose this, then at what point in the evolutionary ladder are these magical properties acquired? Did the trilobite have free will? Does a cat? A dolphin? If not, why not? And if we confine magical properties to just humans, then at what point did we acquire them? Did australopithecus enjoy the blessings of “free will”? So now, to your detailed points. “If thoughts are identical to physical... states and processes, then every thought, including every intention, desire, judgment, or feeling, is an epiphenomenon of forces, forces over which "we" thinking, intending, desiring, judging, feeling subjects have no control” It is true that every thought is an epiphenomenon of physical states. But then you muddle things by separating “me” from my mental states. Who is this “I” that stands apart from the brain and controls it? My actions are “controlled” by my desires, judgements, etc. If my actions result from my desires then they are “my” actions. I do not require some sort of separate self hovering above my brain and somehow making decisions about whether or not to act on my feelings. And how would it make these decisions? Does it have its own feelings, desires and beliefs separate from those it is judging? This is clearly a Mare's Nest. The points you make in your next paragraph I have answered in my exposition above. Then you say: “If physical and mental states are truly identical, then any belief I hold must be identifiably homomorphic with some physical state, at least in principle. 1. Good luck with establishing any empirical evidence for that!” I would say that the evidence for the dependence of our personalities on the brain is absolutely overwhelming. Think of Alzheimer's Disease. As the structure of the brain disintegrates, so the personality evaporates. In the end, all that remains is an organic shell responding to stimuli. How can this even be explained on the basis of dualism? If my personality were separate from my brain, then damage to the brain would no more affect my personality than damage to my big toe. “What can it then mean to believe anything is true? If my "brain state" can be interpreted as a belief that h^2=a^2+b^2 in a right triangle (and vice versa, as these are supposed to be "identical"),then how can that brain's physical state be understood as reflecting truth or falsity?” I think this derives from your falsely assuming that I am maintaining some kind of “translatability” thesis, whereby statements of the form “I believe p” can be translated into statements about physical particles. And obviously a disposition of physical particles is neither true nor false; it just is. But I am not maintaining this thesis. I am saying that being in a state whereby I believe p is realised by (or embodied in) the disposition of physical particles. And this is consistent with physicalism as I have defined it above. I just want to say one more thing, in expansion of the above. One thing you did not deal with is consciousness, or qualia, which (as Descartes noted) is an immediate datum and not an inference. Now, I do not hold that statements about qualia are translatable into statements about physical particles. I hold that qualia and neural events are identical and that this identity is established empirically. “The morning star” and “the evening star” are two different descriptions. They are not translatable into each other. However, it has been discovered empirically that they denote the same thing, namely, the planet Venus. As Frege would say, they differ in sense, but have the same reference. I am likewise maintaining that a pattern of qualia characterises an event that also comes under a physical description. (Boychat.org link) LaudateAgno's post on physicalism