A very brief overview of TDTM

TDTM, for Top-Down Theory of Mind, principally combines a new philosophical stance with two scientific theories:

1. Physicoidealism
2. The theory of evolution
3. The computational theory of mind (CTM)

Any scientific discussion must first define what exists, which is called an ontology or theory of being. I am proposing a new ontology for TDTM that I call physicoidealism. Physicalism is an ontological monism, which means it says just one kind of thing exists. Specifically, it asserts that only the physical world exists, consisting of space, matter, and energy. Idealism asserts that only the mental world exists, consisting of immaterial ideas. Physicoidealism is just the union of these two monisms, eliminating the “only” from each. As the brain is now known to reduce to purely physical phenomena, science has concluded that the ideal does not exist, but this is a bit preposterous considering science is built out of hypotheses, which are ideal. Math, ideas, models, and theories are all nonphysical constructions of the ideal world. Nothing about them precludes the physical in any way, but they are not physical. Yes, of course, our access to them is entirely mediated through physical mechanisms like the brain, computers, and books, but any given mathematical law exists (in an ideal sense) independently of any physical system that uses or refers to it. Scientists do try to divine the “actual” laws of nature, but we can never know if there are any as such. All we can do is create idealized, non-physical models that correlate pretty well with nature. So although we have some confidence “actual” laws of nature do exist since the universe behaves so consistently, we have no way to find them or prove that the laws we come up with are right.

The more adamant physicalists among you will by now be thinking that since reductionism implies that everything is physical, this means anything I am calling ideal is just a convenient fiction or illusion with no real substance. All ideas are fictions and illusions with no physical substance, but that doesn’t mean they can’t impact the physical world. Physical systems like minds and computers can use math and programs and ideas to affect the physical world. How these systems affect the world can only be understood through the ideal concepts of information and algorithm. No amount of study of the mechanics of the brain will ever reveal these important aspects of its programming. Programming is the key that unlocks the ideal world, where logic, mathematics, representations and ideas live. Programs represent possibilities; they use one kind of simplified representation or another to describe bounded or unbounded sets of possibilities, and they describe logical operations that can be used to generate a limited or unlimited set of outputs given any inputs. We can discuss an abstract idea, like a pencil or a cat, independent of any physical implementation and inclusive of possibilities both bounded or unbounded. As Sean Carroll writes1 “Does baseball exist? It’s nowhere to be found in the Standard Model of particle physics. But any definition of “exist” that can’t find room for baseball seems overly narrow to me.” Me too. Also, to be useful programs must ultimately correlate back to reality, tie references back to referents, and allow us to change reality. The mind (and other programs) can do that. So minds add a new capability to the physical world it lacked before, a capability that could only seem like magic to inanimate matter or even plants, the power to predict the future by dividing nature into causes and effects, and thus develop strategies and then act on them. It seems a bit ironic that we consider fortune tellers to be charlatans considering the purpose of minds is to “see” the future so as to better control it. Of course, the limitation is that minds never have certain knowledge of the future, but they are chock full of very good guesses.

Another question that tends to come up about now is “what about determinism?” Physicalism says the world is running on fixed laws and that the outcome is preordained. Now that we have quantum uncertainty, perhaps it is not preordained, but it is still not alterable by free will. I explained in Key Insights why free will exists despite determinism. Although the decisions we made could not have been decided otherwise, they seem like they could to us because we imagine how they could have turned out otherwise, and since the physical world is too complex to predict, no one can tell us we didn’t pick one future out from among many. What makes us free is that our minds dwell in the ideal world of possibilities, and only secondarily in the physical world. In our world baseball and other generalizations exist, but they are not strict physical objects or events. When we are about to do things, and after we have done them, we don’t think only in terms of that specific instance, we generalize to all similar situations. So while actual decisions could not have been decided otherwise, we don’t see decisions in the context of a specific case, we generalize to all similar situations. To function effectively, we have to view the world through this much larger lens of possibility than as a mundane physical world that ultimately lacks any possibility since only one path will unfold. Put another way, at the moment we take an action, we have no choice, it is done. The moment before that, the universe and our minds are simply too complex for it to be possible to predict what will happen, even though we know it must unfold deterministically. So looking forward minds manage all possibilities as possible and interpret their action-optimizing algorithms as choosing from those possibilities, even though they are just making the generalization that situations similar to those in the past will play out in similar ways given similar reactions.

So are human choices actually shaping the world? Yes, because free will actually does exist as we think it does. The only illusion here is the idea that determinism implies the future is simple to predict. It doesn’t. Because it is possible for minds to exist and to gather information, model it, and compute and take actions, the physical world actually includes this slice of the ideal world, and so outcomes that leverage the world of possibility are entirely within the laws of determinism. In other words, determinism is not limited to the “direct” interactions of particle A hitting particle B; information processing and feedback vastly expand the range of complexity of what might happen “indirectly” (I use quotes because everything physical is necessarily direct, it is just that direct can become very convoluted). The physical universe does seem simple enough to predict if you leave out minds, but minds are part of the physical universe. When we change the world around us, it is the physical world changing itself. We are just the most complex cogs in the machine.

So brains create minds, and minds open a window into the ideal world of possibility that actually turns out to be an infinitely richer world than the physical world that spawned it. What do we know so far, scientifically, about how the mind came to be and how it works? Darwin discovered how it came to be with his theory of evolution in 1859 and the computational theory of mind (CTM), proposed in its modern form by Hilary Putnam in 1961, provides the basis of how it works. While Darwin wondered, “How does consciousness commence?”, he didn’t solve it, but he opened the door to evolutionary psychology in The Origin of Species with this comment: “Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation.” We now have a good overall sense of the evolutionary basis of all major mental capacities. The computational theory of mind (CTM) proposes mechanisms to support mental processes. The idea that thought is an exercise in information management and not a standalone substance is a major breakthrough, so far fully supported by the evidence. We now have reasonably good digital algorithms that approximate some mental functions, though we are still far short of artificial intelligence itself.

So far, the implications of these theories for understanding the mind have been best organized into one place in Steven Pinker’s 1996 book How the Mind Works. Pinker covers many implications of evolution and CTM on how the mind works in a very objective way, and I highly recommend it and will build on it. But we have a ways to go. Pinker doesn’t wade into the treacherous waters of metaphysics I’m in. I’ve introduced the idea of a computational idealism that forms an independent monism that has to be combined with physicalism to cover all that exists. From there I have developed the subjective perspective as a referential reality that funnels a cartoon of the world into a stream that can be analyzed logically to make decisions. And I explain free will as a consequence of the future being unknowable combined with action-optimizing algorithms that model possible worlds and pick from them. From where I sit, we need to expand the scope of objective science to include the ideal world, which is not a discovered world but a created one, an engineering project. Logic and math and models and ideas are built, not discovered, and the mind is a software engineering project. So much of how it works is not the simple outcome of scientific laws but the complex result of engineering decisions. The biological and social sciences, of course, accept that life is engineered and that understanding it better requires some reverse engineering, but I think they have historically undervalued the need to apply reverse engineering to psychology. Steven Pinker does an excellent job covering evolutionary psychology, and I will take that thinking further still.

  1. Free Will Is as Real as Baseball, Sean Carroll, 2011, Discover Magazine

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