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Donald Hoffman's Conscious Realism

3. Some Key Objections

Book cover: Philosophy of Mind: A Contemporary Introduction by John Heil

Having summarized Hoffman's theory, here I will outline some of the main challenges that it faces. Beginning with his Fitness Beats Truth (FBT) Theorem, Hoffman and his collaborators may have overstated their case here in a couple of ways. Their FBT modelling does not show all that they say it shows. It may show that in the long run fitness beats truth most of the time, but evolution is an ongoing process. So, in the short run, with constant genetic variation resulting from spontaneous mutations and the random pairing of alleles during sexual reproduction, some members of a species will sense truth to at least some extent.

Secondly, even in those cases in which fitness is maximized through selection, there remains some mapping to external reality, even if it is not homomorphic. Otherwise, to use Hoffman and his collaborator's example [Prakasha et al 2017: 9] of organisms competing for a water resource, the organism using the 'Fitness-only' strategy won't get the water it needs to survive. Shermer makes exactly this same point when he writes, 'Finally, why present this problem as an either-or choice between fitness and truth?' [Shermer 2015].

In fact, in an interview with Frohlich [2019] Hoffman seems to concede this point that our perceptions are truth-tracking to some extent. In replying to the question of why it is that we see the Milky Way when that perception has no fitness payoff, Hoffman says: 'So the idea will be that evolution has shaped us with a very simplified interface that's been shaped mostly [emphasis added] to report the stuff that's going to keep us alive'. Hoffman goes on to say that even so, we misjudge the relative distances to distant mountains, stars and the moon because these distant objects all have the same low 'fitness payoff' for us. So, according to Hoffman, our perceptual systems are 'representing' objective facts about fitness cost and 'report' information to us about objective reality to the extent needed to keep us alive.

Another key objection is that his FBT is self-refuting. Consider how Hoffman, himself, is the result of human evolution. And yet, purportedly, he discerns many facts grounded in observation. Here is just one such fact about the world that Hoffman discovered from his observations of evolutionary processes and from working with his peers. He states that the classic argument that veridical perception offers a competitive advantage 'misunderstands the fundamental fact about evolution, which is that it's about fitness functions — mathematical functions that describe how well a given strategy achieves the goals of survival and reproduction' [Gefter 2016]. If we can't know anything about a world external to conscious minds undergoing selective environmental pressures, then how can Hoffman have found out that fact about just such a world?

For the full treatment of objections to the Fitness Beats Truth (FBT) Theorem, see Sec. 2 of my Hoffman's Conscious Realism: A Critical Review.

Turning now to the problems inherent in Hoffman's Interface Theory of Perception (ITP), the main objections are these. Firstly, in dismissing veridicality of the icon on our desktop, Hoffman and his collaborators may be pressing their analogy too far. Clearly, the icon on our desktop is representing a file in some respects. It's a mistake to think that to represent the file with some level of veridicality, the icon needs to be identical with the file. The icon is, after all, a representation. A map can faithfully represent the terrain it maps without being identical to the terrain.

On the veridicality of our perception of distance, Hoffman et al [2015a: 1497] point to 'obvious cases where our perceptions radically disagree with our careful measurements'. They point to how the 'sun, moon and stars, for instance, all look far away, but they all look about equally far away'. For these objects, Hoffman offers a standard evolutionary account for why we misperceive their relative distance. In his interview with Frohlich [2019], he contrasts the evolutionary advantage gained from perceiving close distances accurately:

So the idea will be that evolution has shaped us with a very simplified interface that's been shaped mostly to report the stuff that's going to keep us alive. ... The distance from me to an apple, say, here like two meters away versus another apple, you know, 20 meters away—that distance is coding the percentage of my caloric resources that I currently have that would be required to be expended to get the resources in the apple at two meters versus 20 meters. In other words, distance is a calorie expenditure representing fitness cost.

Here, Hoffman has let the cat out of the bag. To explain why perception of very large distances is non-veridical, Hoffman illustrates his point by contrasting this case with a situation in which veridical perception of distance is necessary for survival. In the case of getting an apple, evolution selects for accurate perception of distance, otherwise we would be expending uneconomical amounts of calories.

Book cover: Metaphysics: A Very Short Introduction by Stephen Mumford

The most serious objection to Hoffman's ITP is that it is parasitic on scientific realism. Hoffman borrows from his realist opponents' metaphysical framework without paying its dues. In answer to the question about how we could have landed a spacecraft on Mars with pinpoint accuracy if natural selection did not design our senses and brain to construct a relatively accurate model of reality, Hoffman invokes his and his team's Invention of Symmetry Theorem (IOS) to demonstrate mathematically how we can map, using symmetry, planarity and compactness, perceived shapes in a 3D space to another non-actualized dimension. They make it seem as if successfully landing a spacecraft on Mars is simply a matter of getting our hand-to-eye coordination right.

However, that mathematical mapping scheme may be adequate for explaining the successful manipulation of 'icons' within a spatio-temporal field. When it comes to landing a spacecraft on Mars, what Hoffman et al ignore is the essential role that theory construction plays in scientific achievements. The feat of landing a spacecraft on a planet millions of kilometres from Earth was not achieved by simply using a joystick to manipulate the 'icon' of a spacecraft within a virtual reality game. That achievement is not like playing a space video game in which our only task is to co-ordinate our eyes and hands within a set of pre-established game rules.

Landing a spacecraft on Mars is the end result of centuries of hypothesizing and testing models of reality in the fields of physics, astronomy and cosmology against predicted future perceptions. To put a spacecraft on Mars, scientists first needed to understand what lies under the bonnet of our everyday perceptual world, so to speak. Space scientists only got to know how to build the spacecraft, send it into space and control its landing by first theorizing and understanding the underlying physics that govern planets, rockets and spacecraft. It is only after the theoretical and experimental hard work had been done by scientific realists that Hoffman et al are able to reverse engineer the mapping of manipulations of physical objects in space-time to achieve the Mars landing.

For the full treatment of objections to the Interface Theory of Perception (ITP), see Sec. 3 of my Hoffman's Conscious Realism: A Critical Review.

These first two theories, Hoffman's Fitness Beats Truth (FBT) Theorem and his Interface Theory of Perception (ITP), culminate in his third theory, Conscious Realism. This theory has its own set of problems. The first challenge with Hoffman's Conscious Realism is that it reduces our ordinary way of speaking about everyday objects to absurdity. For Hoffman, physical objects literally pop into and out of existence as we change our point of view. Hoffman puts it this way: 'we create an apple when we look, and destroy it when we look away. Something exists when we don't look, but it isn't an apple, and is probably nothing like an apple' [Dickinson 2019]. But if the apple ceases to exist when I'm not looking at it, then how can something that ceases to exist nourish me once I've swallowed it and can no longer see or feel it? For that matter, what stops me from falling from the sky when I'm not looking at the aeroplane wings on my flight to London?

A related problem for Hoffman is how to individuate objects, such as tennis balls and cars, on his schema. A realist view about external physical objects explains naturally the singular identity of things that are perceived by more than one person. Hoffman's theory, on the other hand, generates puzzles that strain language conventions to breaking point unnecessarily.

A particularly incisive observation that Dickinson [2019] makes is that if the icons on our desktop reveal nothing about a mind-independent reality, then perhaps our consciousness is just another icon. Perhaps Dickinson is even being too generous to Hoffman here because it seems the conscious agent, our 'I', is not even an 'icon' on our desktop. As the Buddha and Hume have pointed out, we don't perceive the thing doing the thinking. The conscious agent, our 'I', is just as much a theoretical construct as the mind-independent physical objects we perceive.

On Hoffman's schema, the existence of other minds seems to be on even shakier foundations. Whatever can be said of perceiving our own mind, we don't perceive other minds at all. They are not even represented as 'icons' in our perceptual field. We only perceive the physical bodies that they purportedly inhabit. If, on Hoffman's view, we should ditch our belief in physical bodies in order solve the intractable mind-body problem, then how more so should we abandon belief in other conscious agents to solve the wicked problem of other minds? It's hard to see how Hoffman's metaphysical clean up does not lead us inexorably down the path to accepting a thorough-going solipsism.

For the full treatment of objections to Conscious Realism, see Sec. 4 of my Hoffman's Conscious Realism: A Critical Review.

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