stevendaryl said:
It's not clear to me that there is any substance to the disagreement between physicalists and such platonists. It's an argument over words.
Philosophically, it makes all the difference in the world. Gödel and other prominent scientists have for example have used such arguments to 'prove' the existence of God.
Is an abstraction such as "the number 2" or "a function" or "a sort routine" something that "exists"? Everyone agrees that they don't exist as physical entities--you can't hit somebody on the head with an abstraction. Everyone agrees, on the other hand, that they are coherent topics to reason about. The disagreement is over what "exists" means. What difference does it make?
I will quote Poincaré from The Foundation of Science:
Poincaré said:
What does the word exist mean in mathematics? It means, I said, to be free from contradiction. This M. Couturat contests. "Logical existence," says he, "is quite another thing from the absence of contradiction. It consists in the fact that a class is not empty." To say: a's exist, is, by definition, to affirm that the class a is not null.
And doubtless to affirm that the class a is not null, is, by definition, to affirm that a's exist. But one of the two affirmations is as denuded of meaning as the other, if they do not both signify, either that one may see or touch a's which is the meaning physicists or naturalists give them, or that one may conceive an a without being drawn into contradictions, which is the meaning given them by logicians and mathematicians.
Carrying on.
I disagree with that. The theory of computation is not a description of anything that exists in the world. It's not a placeholder. It's more akin to mathematics. Mathematics can be used to describe the real world, but the theory of the natural numbers is not a description of some aspect of the natural world. You can use the theory to reason about counting rocks, or whatever, but there is no sense in which the theory is a placeholder theory to one day be replaced by a more physical theory of rocks.
This is simple really. Let's use an analogy:
Are cells things which exist in the natural world? Yes. Can there be a physical model describing them? Yes. Can there be a more abstract purely formal model describing their workings? Yes. Can that theory therefore be regarded as a special theory about cells from another domain (biology), which strictly describes natural phenomenon? Yes.
Therefore, cells and even their mathematical abstractions can be viewed as falling under the purview of physics.
Replace the word or concept 'cell' in the above with the word 'computer' or 'fridge' and it becomes immediately clear that the same applies to them as well.
From a pure biology point of view, cells can even be described in a myriad of ways, even outside of any organic chemistry, the Standard Model of particle physics or physics at all by purely referring to their function in a formal description; recall that the same applies to the 'gene' concept that Darwin invented long before people started thinking about DNA. Doing this is a way of completely removing physics from the equation, but to then go onto state that such things actually (can) exist is to immediately make a falsifiable claim about physical phenomenon.
The fact that we do not characterize computation as Turing defines it necessarily as a physical phenomena but as a formal one does not imply that such a characterization is impossible; I would even argue any actual instantiation of a Turing machine carrying out computation in the real world clearly is a physical phenomenon and all physical phenomena capable of being described this way fall under this class.
Of course, you can regard the theory as belonging more properly to mathematics, I in fact do the same as well. But this gets us into the ugly business of tacitly reifying abstract mathematical things, and possibly confusing what is or is not physical in the case of instantion when all instantion seems to necessarily be physical. This gets us too far into what is mathematics and what is physics discussion; if we are talking about phenomena that exist in the world and their properties, as we are when we are talking about minds and actual computers, then we are necessarily talking about physics. The fact that the classification of things in physics is so different than how classifying phenomena works in e.g. biology or astronomy is more what we arguing here.
I just think that you are misunderstanding the topic. I think that there is a conflict of interest in your role in this discussion, because you are both trying to define a position, and simultaneously attacking that position. That's not intellectually honest. That is what "attacking a strawman" means. Maybe there is somebody who believes the position that you are attacking, but they aren't arguing in this thread, so why should anyone care?
I am defining a prevalent position in this discussion in academia, even if it doesn't seem to be one on this board. First and less interestingly, it is because it doesn't seem to be true as is argued in the paper by Glymour which I linked, please have a look at that.
Second and I think more importantly, let me tell you why you should care, seeing you don't seem to be aware of or directly experience the unwanted side effects.
I have spent hours in real life arguing with non-physics academics, specifically scientists from neuroscience, biomedicine and cognitive psychology on interdisciplainary discussions about this matter. They are the ones who not only mostly research the mind, write textbooks and construct curricula and so perpuate the false idea in new students, but also decide what research gets funded. This means when it is time to decide which research should be pursued and funded, only those proposals which clearly jive with the functionalist argument, taking the mind to be necessarily isomorphic to ideas from computer science as fact and therefore de facto removing any need for any physics approaches, tend to get chosen. This is purely because these people are convinced that argument is true; it is a terrible tacit selection criteria for doing research, but it is the situation which we are in.
This stance has immensely crippled many more physics and applied mathematics interdisciplainary type research proposals in these topics (which are strongly underrepresented but badly needed) mainly due to the acceptance of the argument by many, due to the alienation of the few physics researchers who do try to research the mind, and due to many uncritically thinking computer science and physics proponents and popularisers continuously echoing this argument. This has stifled among many others the dynamical systems approach to the mind for over at least a decade, certainly at the university I work and has completely alienated the physics group who were once interested in working with biologists on neuroscience topics.
It is only in the last year I have even ever seen a proper challenge against this trend (by a biologist of all people) arguing for doing research into the practopoietic theory of the mind. This is a novel - fundamentally non-functionalist - biological theory of consciousness based on an actual description of biological observations, in line with the mathematics of non-equilibrium thermodynamics research from (non-high energy) theoretical physics research and deeply connected to non-linear dynamical systems theory by being a dimensionless parameter updating model in bifurcation theory. When the other physicists/applied mathematics looked at it carefully, they unanimously quickly saw not just the potential of this theory but all its possible mathematics and physics spinoffs and backed it pretty much immediately.
@Buzz Bloom Actually Wikipedia agrees exactly with me:
"There is much confusion about the sort of relationship that is claimed to exist (or not exist) between the general thesis of functionalism and physicalism. It has often been claimed that functionalism somehow "disproves" or falsifies physicalism tout court (i.e. without further explanation or description). On the other hand, most philosophers of mind who are functionalists claim to be physicalists—indeed, some of them, such as David Lewis, have claimed to be strict reductionist-type physicalists.
Functionalism is fundamentally what Ned Block has called a broadly metaphysical thesis as opposed to a narrowly ontological one. That is, functionalism is not so much concerned with what there is than with what it is that characterizes a certain type of mental state, e.g. pain, as the type of state that it is. Previous attempts to answer the mind-body problem have all tried to resolve it by answering both questions: dualism says there are two substances and that mental states are characterized by their immateriality; behaviorism claimed that there was one substance and that mental states were behavioral disposition; physicalism asserted the existence of just one substance and characterized the mental states as physical states (as in "pain = C-fiber firings").
On this understanding, type physicalism can be seen as incompatible with functionalism, since it claims that what characterizes mental states (e.g. pain) is that they are physical in nature, while functionalism says that what characterizes pain is its functional/causal role and its relationship with yelling "ouch", etc. However, any weaker sort of physicalism which makes the simple ontological claim that everything that exists is made up of physical matter is perfectly compatible with functionalism. Moreover, most functionalists who are physicalists require that the properties that are quantified over in functional definitions be physical properties. Hence, they are physicalists, even though the general thesis of functionalism itself does not commit them to being so."
This clearly says three things:
- There are many people who argue that functionalism disproves physicalism; these people tend to be cognitive psychologists who reject physicalism altogether and religious people arguing for some form of dualism, in this case namely by appealing to ontological functionalism to disprove physicalism.
- Functionalism need for many not refer to ontological functionalism meaning they do not regard functionalism as a theory of ontology, i.e. to them it does not concern itself with what exists like physicalism and dualism among many other theses do; 'ontological physicalism' is a nonsensical term since physicalism is always about ontology, i.e. about what exists in the real world.
Therefore the stance - let's call it 'minimal functionalism' to avoid confusion with other forms of functionalism - need not be in strict disagreement with physicalism.
- Type physicalism (an identity theory of mind and body i.e. some physics) is incompatible with functionalism.
I, along with Penrose btw, am very much arguing for an identity theory of physicalism, whether that be first order as in type theory or second order as in token theory or higher order. Moreover, it is important to pay attention to details like this because this subject is directly related to clinical practice, meaning actual guidelines for treating comatose and neuropsychological patients are constructed and used by physicians on a day to day basis on the basis of exactly such arguments.
stevendaryl said:
Is there any substance (no pun intended) to what you're saying, because arguing over words? Is something physics, or not? What difference does it make? Can you relate whatever disagreement you are having back to this thread?
If you're just saying that you don't think someone should be considered to be studying the mind unless they are studying the physical properties of the brain? Is that just a matter of labeling?
It's deeper that that as I have tried to explain above how such 'semantic trivialities' seem to dominate interdisciplinary research programmes by imposing tacit selection criteria upon research, an unwanted emergent phenomena in science due to the politics of academia (pun intended).Not recognising e.g. that emergence can be studied using methods from physics is doing a disservice to both that emergent phenomena and to physics, for it inhibits unforeseen offshoots in both directions.
If you are questioning whether it is useful to regard dynamical systems as a subject in either mathematics or in physics, I would just answer it is a subject in both, properly even mathematical physics (regardless of the content of what is necessarily thought in contemporary mathematical physics programmes).
