Sunday, May 01, 2016

"The Case Against Reality"


That is the title of an Atlantic interview with professor of cognitive science Donald D. Hoffman. The interview seems to conflate three different issues: (1) whether reality is observer-dependent; (2) the entanglement of quantum states; (3) whether living creatures have accurate perceptions or adaptive perceptions.

I don't know much about quantum mechanics, but evidently quantum entanglement does not entail an observer-dependent reality, despite this widespread belief (at least among the public and among purveyors of popular science). An easy way to see the difference is that quantum entanglement happened even before there were biological organisms observing the world. Macro-level observations of phenomena are not required by quantum entanglement. (Quantum entanglement is about the mutual dependence of the states of different quantum particles, such that the state of each particle cannot be described independently of the states of the others.)

Secondly, the issue of whether humans and other organisms that evolved through natural selection have adaptive perceptions rather than accurate perceptions is fascinating, but it seems irrelevant to quantum entanglement. It's true that human perception of objects as independent realities does not correspond to the quantum mechanics picture of reality, but then again neither does it correspond to the general relativity, nor even to Newtonian physics (e.g., inertial motion).

Even when we discuss the narrow issue of whether ordinary objects really exist, it would seem that classical physics also undermines realism about ordinary objects, because of the view that such objects are completely reducible to atoms or other constituent particles, and so have no independent causal powers or other real-making features. Quantum mechanics does pose special challenges or realism about ordinary objects, but it is by no means unique in this regard.

The issue of realism about ordinary objects has been discussed for a long time in philosophy, and I think cognitive scientists and popular science writers would benefit by examining this literature before holding forth about the metaphysical implications of quantum mechanics, neuroscience, and so on.

In addition, at the end of the interview, Hoffman posits conscious experiences as ontological primitives (i.e., the basic constituents of reality). It's true that conscious experiences could be distinct from our perceptions of ordinary objects, and thus realism about the former does not imply realism about the latter, although presumably this would require that conscious experiences not include experiences of real objects (such as if the conscious experiences are constituents of perceptions of real objects).

But there are two confusing things about this proposed ontology. The first is that the ontology of conscious experiences is incompatible with the initial argument given for the claim that we don't perceive reality. The initial argument was that our perceptions of real objects do not accurately reflect quantum entanglement. The presumption was that quantum phenomena are the basic constituents of reality. But now Hoffman is saying that conscious experiences, not quantum phenomena, are ontologically primitive.

The second confusing thing with Hoffman's proposed ontology is that it doesn't seem to fit with his claim that our perceptions are adaptive but not accurate. Assuming that our perceptions are composed of conscious experiences, how could they fail to be accurate (at least in some sense), if they include the fundamental constituents of reality? Technically, the perceptions would not be accurate as representations of reality, because they themselves contain reality. But still, this is a different picture which makes the initial claim look like a bait and switch.

I am left wondering if I am the one who is fundamentally confused here, or if it is Hoffman, or the interviewer, or all of the above. But this sort of confusion is typical when non-philosophers try to talk about metaphysics or other philosophical questions (ahem), which makes me realize the value of philosophy as a discipline (even if we maybe we do have more philosophers than we need and could do with more doctors or nurses, for example :) ). I am left almost happy about the terrible conceptual muddle that seems to be contained in this article, because at least it shows that there is a need for philosophy to help untangle the conceptual knots or unclog our conceptual plumbing.
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