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I've only read the linked article, not the more in-depth source mentioned there. But based on just that information, I'm deeply unimpressed by Hoffman's work. From where I stand, his idea is both poorly informed (as in, it seems like he's not made a credible effort to examine his premises) and, ironically, proven wrong by reality. That's a pretty contentious statement for a non-expert to make about a presumed expert, so I'll try to explain myself.

First, like some other commenters, I'm happy to concede that at a trivial level H. is quite correct. The world around us as perceived by the unaided human is mapped inside his brain to a vague, sometimes exaggerated, sometimes obscured and very often distorted image of reality. There are entire books on optical illusions; the trade of stage magic and various kinds of crime rely on systematic human misperceptions.

There's an obvious, perfectly good reason for this: the human system of vision is simply not a pixel-perfect 3D camera connected to petabytes of fast digital storage, and the same applies to our other senses. Given a perfect recording of the world at least in our vicinities, abundant energy and sufficient time, we could come up with highly effective survival strategies. But the real world doesn't afford us these luxuries, so evolution crafted us into organisms tuned for a reasonable approximation to an optimal compromise of this ideal. Thus, our mental model of the world is a crude abstraction, with survival-relevant information emphasized and other details brushed over. This is not a survival-optimized transformation of reality but a constraint-enforced one. A highly sophisticated system built on the shoestring budget that nature affords us. It's proven to be superior at survival to many competing models but I don't agree it works better for misrepresenting reality. Rather, it works _at all_ by necessarily sacrificing detail and accuracy in representing reality.

But none of this supports H.'s contention that we are blithely unaware of reality, or unable to apprehend it. There is a reality out there, and the depth and accuracy of our model is a function of how much time and energy we're willing to expend on mapping it. A given beach, sharply defined, has a finite and very countable set of grains of sand. If we really, really cared to know, we could build machines to count them for us. Similarly, we can or could know the shape of every coastline of every continent. Some day, humanity may have high-quality reality mappings of every planet within X light-years of our solar system. We can in principle understand the function of every gene in our genomes. We don't have to talk about how we perceive colors, because spectroscopes can tell us the exact, reproducible wavelength of every beam of light emitted by a given object. We could exchange this information with aliens having completely different bodies and brains, should we discover them, and if their science is as advanced as ours and we're careful to define our terms and measurements on observable nature, we'd have a common understanding of that reality.

But how do we know that our reality is real? How do we ascertain truth? I say we can base a pretty solid epistemology on a confluence of observed phenomena. If we encounter an obstacle we can't see through, if it's grey in color, weighs about 6 tons, stands on 4 legs, has a long nose, occasionally moves around and eats bananas by the bushel, then we can safely assume we've found an elephant. If it's a chunk of some yellow shiny solid that displaces 18 grams of water per cc, and samples drilled from arbitrary locations in it uniformly have atomic weights of X (?), melting points of Y degrees, fail to react with sulphuric acid and show a chromatographic signature consistent with that of gold, then by golly, it's a chunk of gold!

As humanity, not as individual naked humans, we've amassed a large and ever growing body of knowledge about the world around us, and (fortunately for our sanity and our ability to make sense of reality) the properties of objects and phenomena in our environment are consistent and convergent. There are no 1 gram elephants, there is no sodium that doesn't react violently with water, there are no snowflakes whose basic structure isn't hexagonal. We know that our image of reality is good because we're able to extrapolate from what we know and observe to what we haven't observed yet, to make predictions about what we'll observe and have those predictions prove mostly true.

The author and his (perhaps coincidental and unintended) idol Plantinga fail to acknowledge humanity's ability to create models of reality of whose accuracy (within limits) we can be confident because they're part of a huge network of mutually supporting sub-models with excellent predictive power. And, more importantly, that our ability to create such mappings is a human ability that we have evolved to have. A goodly part of this evolution is cultural rather than biological, and a goodly part of our senses are mechanical and external rather than built into our wetware, but our evolution and that of our apparatus is quite natural insofar as everything that we humans, natural beings in a natural world, are natural too and a part of nature.

Hoffman's conjecture is completely, utterly wrong: Evolution has in fact "bred" in humans the ability to discover reality, and this ability has incidentally given us dominion, at least in the short term and for whatever that's worth, over all other species on the planet, including our own ancestors and close cousins. Our ability to apprehend reality has made us so fit that, barring various possible disasters, we could survive the death of the Sun and Earth.

If Hoffman wants to support his claim that a creature who views too much and too little water as similar instances of "bad amounts of water" would display a higher degree of evolutionary fitness than us, I feel he has his work cut out for him.



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