Friday, December 7, 2012

Ed Feser makes some odd claims about appearances, science, and reductionism

I want to start with two propositions that I hope are uncontroversial and accessible to the common man. Hell, at least one of these is accessible to my cats.

1. My couch is red (you have to trust me on that part). When I look at it it appears "red" as I've come to know the term. When I turn out all the lights at night, it appears "black" as I've come to know that term. It's not even that I see no couch. I can still make out a couch quite clearly, and it looks relatively black.

2. When you hit someone in the leg with a baseball bat they remain conscious. Indeed, they become very conscious of their leg at that point. But they're aware of the world around them. When you hit someone on the head with a baseball bat, they become not-conscious.


Now on to this post by Ed Feser (HT - Gene Callahan and Bob Murphy). Feser writes:

"Take a stock example of reductive scientific explanation like the reduction of sound to compression waves, color to surface reflectance properties, or heat and cold to molecular motion. The way these explanations work is by treating the appearance that sound, color, heat and cold present to us in conscious experience as mere appearance, as a projection of the mind that corresponds to nothing in objective, mind-independent reality. What common sense understands by color, sound, heat and cold -- the way red looks, the way a musical note sounds, the way a hot stove feels, and so forth -- is held to have no objective reality, any more than the redness a person unknowingly wearing red-tinted contact lenses thinks he sees in all the objects around him really exists in those objects. Instead, color is for scientific purposes essentially redefined by the method in terms of the surface reflectance properties that cause in us the subjective appearance of color; sound redefined in terms of the compression waves that cause in us the subjective appearance of sound; and heat and cold redefined in terms of the molecular motion that causes in us the subjective appearance of heat and cold.

Thus, as common sense understands color, sound, heat and cold, etc., the reductive method ends up treating the world as essentially colorless, soundless, devoid of temperature, etc. What the method calls “color,” “sound,” “heat” and “cold” is in fact something different from what the man on the street thinks of when he hears these terms. The “red” that the method says exists in the material world is just the tendency of an object to absorb certain wavelengths of light and to reflect others. The “red” that the man on the street thinks exists in the object does not really exist in the object itself at all but only in his perceptual experience of the object. The “heat” that the method says really exists in the material world is just the motion of molecules. The “heat” that the man on the street thinks exists in the object does not really exist in the object at all but only in his perceptual experience of the object. And so forth."

None of this seems right at all to me. We get the basic science of color that he describes as men on the street. We know that light helps us access colors and we know that with less light we see less color. The man on the street has no trouble processing that there's a relationship there.

What's more is that contra Feser, the scientist does not strip the object of any of its qualities when he adopts the perspective of the man on the street and explores the color-light-appearance relationship further. The couch still has the quality of being "red" for the scientist. It is not colorless as Feser asserts. The scientist just asks exactly what the nature of this "red" quality is, and provides more details on that. If objects themselves had no color then the explanation of the appearance of color in terms of light waves (something the man on the street has no trouble accepting) wouldn't make all that much sense would it! What would determine that my couch is red while another couch is blue if it weren't something about this couch that makes it look that way when the room is lit?

So starting with this problematic reductionist account of what scientists do (and a quite demeaning account of the man on the street), Feser moves on to consciousness:

"Now, Nagel’s point is not that there is something wrong per se with overthrowing common sense in this way. It is rather that whatever value this method has, it cannot coherently be applied to the explanation of conscious experience itself. If the reductive method involves ignoring the appearances of a thing and redefining the thing in terms of something other than the appearances, then since our conscious experience of the world just is the way the world appears to us, to ignore the appearances is in this case just to ignore the very phenomenon to be explained rather than to explain it. Consciousness is for this reason necessarily and uniquely resistant to explanation via the same method scientific reductionism applies to everything else."

This seems wrong too, and it's wrong again precisely because Feser misunderstands science when he associates it with reductionism. What is the man on the street understanding of consciousness? Well it's clearly something that normally functioning brains do. When you hit someone's leg with a bat they are conscious, but when you hit their head with a bat they are not conscious. And you can know that because they can wake up eventually and confirm they were not conscious. So there's something about normally functioning brains that consciousness is conditional on. We're not "overthrowing common sense" in saying that. Quite the contrary - we are following our common sense and seeing where it leads us. Yes, it would be hard to study consciousness scientifically if we ignored appearances. But we don't do that. It would be hard to study anything scientifically (forget consciousness! It would be hard to study color) if we ignored appearances.

Far from ignoring appearances, the whole point of science is to use appearance to understand the world around us. Another word for "basing our conclusions on how things appear to us" is, of course, "empiricism". It's not the only way we understand the world around us, but it's a very important way and particularly important to science.

The problem is that our perceptive faculties have evolved to suit the survival of apes. That's fine, but it imposes limits. We can't see a lot of the electromagnetic spectrum for example. We can't hear everything either. So scientists have generally made inferences from what the man on the street can perceive, but then they supplement those inferences with observations that a man on the street carrying a telescope can perceive. Nobody is getting past appearances. They are saying that these appearances of the man on the street are great for navigating the universe - so great, in fact, that we want to collect data on all of it and then when we're done collecting that data we want to build machines that enhance our perceptive faculties and allow us to collect data on even more appearances.

This seems to be the sticking point for Feser: "To treat the appearances as essentially “subjective” or mind-dependent is precisely to make them incapable of explanation in entirely “objective” or mind-independent terms."

And I actually agree with this claim. But I would say that if he's trying to explain things in "objective" or "mind-independent terms", he's barking up the wrong tree to begin with.


  1. Excellent post.
    The man in the street knows about color blindness too, so he knows color has a brain component. He's proabaly seen things under fluorescent light. He doesn't imagine there's some red essence permeating your couch. Maybe the monk-in-the-street did in 1033 but not the typical modern American.

    1. And even the monk on the street knew there was some color/light connection. He knew at night everything looked black. Science doesn't toss any of that out. What science does is validates our appearances. It may validate the appearance by telling us something non-intuitive about why things appear the way they do. But often (as in this case), it gives us more detail on appearances that we get a good way in explaining ourselves. In no case does it toss out appearances. One way or another appearances are explained - either in a more intuitive way or a less intuitive way. And they are explained by adding more appearances and experiences (through more powerful telescopes, microscopes, data, etc.) to our usual set of appearances and experiences.

      I don't know how cats see color exactly, but my reference in the beginning to my cats was that they behave differently upon turning off the lights at night. They understand that the appearance of the world changes with and without light and you can see them moderating their behavior as a result of that understanding. They know there is a connection between the light and the room and the appearance of color. This is man-on-the-street stuff.

  2. This is one of the reasons why I said asking brain researchers is more enlightening than asking cherry picked philosophy profs. Brain scientists know how science is actually done. No brain researcher would say the kind of thing about science Feser says.

  3. I don't think you understand what the argument is about.

    1. Ya big surprise Lee.

      Every time you say this (and I've got reams of examples) it ends up that you've dumbed down the other guys argument.

      See my next clarification on reductionism. People use that word to imply a lot of different things. One is a lot more tenable. Feser goes a lot farther than that. You may be thinking that Feser is making the more reasonable claim and that I am missing that reasonable version (I can only speculate - like Steve Landsburg the other day you don't elaborate on what you think I misunderstand)

      Also keep my last two paragraphs in this post in mind. Part of this is that Feser is fundamentally wrong about the tasks scientists set themselves to (which is different from the task that [most] philosophers set themselves to when they talk about science). I'm a scientist that studies scientists. I am early in my career but I'm not making things up on the fly here either. Philosophers concerned with these questions get a lot more esoteric in what they refer to as "science". If you want to talk philosophically about that, about demarcation issues, etc. be my guest. But that's a separate issue from talking about what science actually is (which is what Feser is trying to talk about).


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