Appearance Pluralism, Perception, and Causation

Appearance Pluralism, Perception, and Causation

Guy Longworth[1]

University of Warwick

March 08

1. My aims here are fairly limited. They’re also a little incestuous, since my main target is the first main chapter of my colleague A. D. Smith’s book The Problem of Perception. Smith’s book is mainly about a version of the Argument from Illusion and how he thinks we should respond to that argument. My aims today are the following. First, I want to sketch the Argument, as Smith appears to understand it, pausing every so often to worry at some of Smith’s formulations. Second, I want to focus more closely on a particular sort of response to the Argument, a response that Smith associates with the early 20th Century movement called New Realism, but which I think can be detached from that setting. Here, I want to consider what Smith thinks is wrong with that response, adding some considerations from the work of Sydney Shoemaker. I won’t be able to respond fully to the complaints pressed by Smith and Shoemaker, mainly because I’m not yet in a position to mount such a response. Rather, my aim is limited to pointing to some hoops that someone who seeks to press their complaints would need to jump through, or push us through, before it would be clear that there was really something wrong with the broadly New Realist response to the argument that Smith presents.

Let me say from the outset what I’m not trying to do. First, I’m not trying to argue that the New Realist type response provides a blanket answer to the Argument from Illusion. For one thing, even in Smith’s hands, the Argument from Illusion appears to shade into an Argument from Hallucination. And the New Realist type response to the Argument from Illusion is implausible as a response to the Argument from Hallucination. Second, I’m not suggesting that the New Realist type response provides the optimal, or even a viable, response with respect to any case of illusion. All I’m attempting here is a sketch of some of the ground over which future dispute over the standing of the New Realist response should take place. Third, then, I’m not suggesting that there aren’t other, better objections to the New Realist response than those presented by Smith and Shoemaker. I’d be pleased to hear about such objections in discussion. But my present concern is limited to a particular class of objections. Finally, I’ll be focusing on visual perception and take no stand about how the issues discussed here might play out with respect to other forms of perception.

2. Let me begin by sketching Smith’s version of the Argument from Illusion. The argument is designed to undermine what Smith calls “Direct Realism”, a view according to which what we see, or what we see directly, includes mind-independent objects and perhaps mind-independent features or properties of mind-independent objects. In the first instance, I think “Direct Realism” is supposed to be construed as a form of Naïve Realism, so to include at least the following two components:

(1) The phenomenal character of our perceptual experience is at least partly constituted (as I’ll sometimes put it shaped) by objects and properties of which we are aware in having the perceptual experience.

(2) The objects and properties of which we are aware in having perceptual experience and that go towards shaping the phenomenal character of our perceptual experience are mind-independent objects and properties, at least to the extent that they exist independently of being experienced and are possible objects of experience for perceivers other than us.

I think that Smith takes Naïve Realism also to include a third component, according to which the objects and properties that we see play a particular role in determining the phenomenal character of our visual experience.

(3) The form of awareness involved in the perceptual experience we suffer through vision, and which shapes the phenomenal character of our experience, is the form seeing. Thus, the objects and properties that partly determine the phenomenal character of the perceptual experience involved in our seeing are just the objects and properties that are seen by us.

Obviously, there is much more to be said in spelling out this type of position. And there is no reason to expect that all who take themselves to endorse Naïve Realism should endorse all components on all spellings out. But the sketch here will do for present purposes.

Smith’s own response to the Argument from Illusion involves dividing up the objects and properties that play a role in shaping our experience into, on one hand, those that go towards determining the phenomenal character of our experience and, on the other hand, those that we see. He thinks that by drawing that distinction, he is able to explain phenomenal character by appeal to mind-dependent properties without thereby threatening the idea that what we see are mind-independent objects and properties. His idea is that the Argument from Illusion shows that we need mind-dependent properties to explain the phenomenal character of our perceptual experience, since there is insufficient variety in the world to explain the various ways the world appears to us in experience. And he thinks that if those mind-dependent properties were also the things we see in undergoing perceptual experience, they would occlude the mind-independent objects and properties that we naively take ourselves to see. The problem of perception, for Smith, is to explain how there can be space for his favoured combination of views.

As we’ll see, the New Realist type response takes a slightly different tack. The idea driving the response is that the objects and properties awareness of which shapes perceptual experience are mind-independent objects and properties. In order to sustain that idea, the New Realist appeals to the further idea that the mind-independent world contains a sufficient plurality of properties to explain the vicissitudes of experience to which the Argument from Illusion makes appeal. Hence, according to the New Realist response, there is no need to appeal to a plurality of mind-dependent properties in order to sustain the first component of Naïve Realism. But I think that the New Realist can afford to remain neutral about whether the mind-independent properties to which they appeal in order to explain phenomenal character are properties that we ordinarily see. The more minimal version of their view is that they are properties of which we are aware, whether or not our awareness takes the form of seeing them.

So, Smith endorses Naïve Realism (1) and amends Naïve Realism (2) in line with his distinction between two roles that objects and properties of awareness can play in shaping experience. And he rejects Naïve Realism (3). The New Realist type response, as understood here, endorses Naïve Realism (1) and Naïve Realism (2) and is neutral with respect to Naïve Realism (3).

3. The crux of the dispute between Smith and his more naïvely realist opponents is the status of Naïve Realism (1) and Naïve Realism (2). Smith’s version of the Argument from Illusion is designed to show that at least one of these components must be revised or rejected and that the favoured revision involves giving up the claim that the phenomenal character of perceptual experience is shaped by mind-independent objects and properties. How is the Argument from Illusion supposed to sustain that trick?

3.1. Let’s begin with the first stage of Smith’s presentation of the Argument, including his account of what an illusion is (or, rather, what “illusion” will extend over for purposes of his argument).

Our argument begins…with the premise that perceptual illusion can occur. The term “illusion” is to be understood here as applying to any perceptual situation in which a physical object is actually perceived, but in which that object perceptually appears other than it really is, for whatever reason. [Footnote omitted] It is therefore irrelevant whether the subject of an illusion is fooled by appearances or not. (p.23)

This understanding of “illusion” is narrower than some natural understandings, since we might allow that illusion can strike when no “physical object” is involved. Smith himself appeals to the possibility of auditory illusions, and one might think that these involve sounds. Perhaps Smith includes those amongst the physical objects. Or perhaps he thinks that when one experiences a sound, one typically hears the producer of the sound, often a physical object. But there are other cases. For instance there might be illusions involving rainbows, and there might be illusions involving events.

Smith’s understanding of illusion might also be thought broader than (some) ordinary understandings, as Smith notes:

For example, the world appears differently to those who are colour-blind and to those who are not. This involves illusion, in the possibly unnatural sense here employed. For if I, not being colour-blind, cannot tell red and green things apart, but you can, at least one of these colours must look different to the two of us. So, for at least one of us, that colour cannot look the way it really is. (p.23)

3.2. Why is it supposed to follow from a physical object’s looking different to the two subjects that, for at least one of the subjects, the colour cannot look a way it really is?

Smith’s explains his reason in the following way:

That there “really” is a way the object is “objectively” is a presupposition of the Direct Realism that is under investigation here, and so will not come up for discussion. (p.23)

The most important feature of this passage is the claim that “Direct Realism” is committed to there being a way a perceived object is, however many ways it can appear to different subjects. Of course, there being a way is consistent with there also being other ways. But the way this claim appears to function in Smith’s argument strongly suggests that he intends the quantifier to rule out the possibility of there being other ways. Otherwise, it would be consistent with the view that the colour-blind subject and the non-colour-blind subject are both aware of ways the target object is, even though those ways are different. The obvious understanding of the claim then is this: “Direct Realism” presupposes that there is exactly one way a perceived object really is.

That appears to be a remarkably strong presupposition. Some natural questions at this point are the following. Is the presupposition tenable, independently of consideration of illusion (on Smith’s understanding of the latter)? Aren’t there often many ways an object is, even according to natural scientific descriptions of the object, including ways described in physics, chemistry, and perhaps biology? Who is the “Direct Realist” who is supposed to make this presupposition?

Perhaps Smith’s view can be clarified in the following way. Suppose that there is exactly one way each physical object is. Then we might suppose that that way will often include a variety of more specific ways. For instance, the fact that a physical object is one way—for instance, spherical—appears not to rule out its also being a different way—for instance, red. In that case, when we say that there is exactly one way the physical object is, we might mean something like the following. There are a variety of specific ways the object is, and if we take each of those ways and conjoin them, we get a maximally specific way the object is. And there is only one such way the object is.

Smith’s argument would then appear to require something like the following. Each specific way an object “really” is involves a single dimension of variation. With respect to each such dimension, there is only one specific location the object can occupy, so only one specific way the physical object can be. Hence, if it appears to different subjects to occupy different positions along a single dimension, then at least one of those appearances must fail to correspond with the way the object is, for the object can occupy at most one location along any such dimension.

With respect to the present example, the idea would be that there is a single dimension of colour variation, and that an object can really occupy at most one point along that dimension. Hence, the way the object really is cannot constitute the way it appears to both our subjects, since some coloured objects present different colour appearances to the two subjects.

4. That’s the First Stage of the Argument, summarized by Smith in the following way:

(P1.)[T]here is no type of physical feature that may not appear differently from the way it really is to any sense that could possibly perceive it.

From there, we move on to the Second Stage, P2:

(P2)[From P1] …[W]henever something perceptually appears to have a feature when it actually does not, we are aware of something that does actually possess that feature. So, if you are looking at a white wall, which because of the illumination looks yellow to you, you are aware of something yellow.

From the perspective of Naïve Realism, as understood here, the following component of this premise seems more or less incontrovertible. Since phenomenal character is constituted by the objects and features that we’re aware of, something of which we are aware must have the features required to constitute the phenomenal character of the experiences that we enjoy. So, if the phenomenal character of our perceptual experience is of a type that could only be explained by our awareness of something with some property, F, then in order to enjoy experience with that character, we must be aware of something with that property, F. There is a get out clause, since Naïve Realism is only committed to partial constitution of phenomenal character by objects and properties of awareness. But the get out clause is in place to allow that general conditions on experience or ways of experiencing might play a role in shaping perceptual character, and it would be against the spirit of the account to allow specific features of specific experiences to have their phenomenal character shaped by mind-dependent objects or properties. So for present purposes we can allow that the Naïve Realist will accept P2. However, it does not yet follow that that property must be one that, in cases of illusion, is not instanced by the mind-independent objects of which we are aware.

4.2. The Third Stage of the argument is P3:

P3.

…[S]ince the appearing physical object does not possess that feature which, according to the previous step, we are immediately aware of in the illusory situation, it is not the physical object of which we are aware in the illusory situation, it is not the physical object of which we are aware in such a situation; or, at least, we are not aware of it in the direct, unmediated way in which we are aware of whatever it is that possesses the appearing feature—that direct way in which we formerly took ourselves to be generally aware of normal physical objects. (p.25)

If we endorse the three premises, as Smith understands them, we appear to be forced (give or take the get out clause mentioned earlier) to give up Naïve Realism (1) or Naïve Realism (2), or both. We might worry that all the work is being done by the first premise, which is in effect the premise that some cases of things looking some way to us cannot be explained by appeal to mind-independent objects or their properties. And Smith’s argument to this point does not rule out the following type of response.

The phenomenal character of our perceptual experience is partly shaped by the features of things we are aware of. And, where the experience takes the form of visual perception, those features are mind-independent features. However, they are not always the features we say that the things we see really possess; sometimes they are mere appearances. However, that is perfectly consistent with the ways things appear being mind-independent features, features things would possess whether or not we became aware of them.

What, if anything, does Smith have to say in response to that type of response to his argument? Put another way, what argument does Smith have to the effect that some cases of illusion cannot be explained in line with Naïve Realism (1) and Naïve Realism (2)? What constraints are there on the range of mind-independent objects and features that are able to sustain that result?

5. Smith considers a response to his argument at least close to the one just sketched, attributing it to the New Realist movement that flourished in the United States at the beginning of the last century. He writes:

A number of philosophers…have attempted to block [the argument] at Stage Three. The New Realists accept the sense-datum inference: when the tomato looks black to me, I am aware of something black. They deny, however, that I am therefore not aware of a normal physical object… For why should not the blackness that I see be a genuine feature of the tomato? (29)

Although Smith’s characterisation of New Realism brings that position close to the sort of response sketched above, there are two points at which it departs slightly from that sketch.

First, the initial way in which Smith describes New Realism has it committed to objects’ instancing a variety of colour properties, so that the tomato instances both redness and also blackness. But the response sketched here is less radical. According to that response, the tomato instances both the property of appearing red and the property of appearing black, where that is perfectly consistent with it instancing neither redness or blackness.