The Quest for Reality. By BARRY STROUD. (Oxford: Oxford University Press, 2000. Pp. xv + 228. Price £19.99.)
The goal of the quest for reality is to discover what the world is really like, or how things really are (p. 3). This stimulating and thoughtful book is devoted to the particular case of colour.
Stroud begins by trying to clarify the quests philosophical character: Philosophical questions about reality can look and sound exactly like familiar ordinary or scientific questions about reality...But the two must be distinguished, however difficult it is to say what the difference is (p. 4). So the everyday question Are lemons yellow? is apparently to be distinguished from the philosophical question that is expressed in the very same words (p. 4). But surely the philosophical question, Are lemons yellow?, is the everyday questionand many passages in the book just dont make sense if the questions are different. The fact that they are the same question is the reason that philosophical theories of colour are interesting. The difference between asking whether lemons are yellow in everyday life as opposed to the seminar room is not in the question asked, but in the acceptable ways of answering it. In everyday life, examining a lemon in good light is sufficient. In the seminar room, where we wonder whether our perceptions of colour are ever veridical, it isnt.
There are two central strands of argument. Stroud tries to show, first, that colours are not secondary qualities and, second, that the error theorythe view that no material objects are coloredinvolves a kind of incoherence. He clearly thinks that these two positions are importantly alike: the claim that the colors are unreal or "subjective" (p. 60) is repeatedly contrasted with some sort of objective or primary quality view. Although historically motivated, this is an odd way of dividing the contemporary territory. The primary and secondary quality theorists agree that lemons are yellow, which the error theorist denies. Further, although an error theorist might hold that colours are somehow subjective (she might think they are properties of sense-data), she doesnt have to. More fundamentally, the secondary quality theory does not imply that colours are in any philosophically interesting sense less than fully real. Let it be granted that colours are constitutively connected to minds, and that shapes arent. Let it even be granted that objects are not coloured in worlds with no minds. This doesnt show that colours enjoy a kind of second-class ontological status. Mental properties are trivially subjective or not independent of us, but are not thereby less qualified to be part of reality. Why is it any different with colour?
The first strand of argumentagainst the secondary quality theoryhas some peculiarities. Take, for example, Strouds distinction between two versions of the view that yellow is the disposition to produce a perception of a certain property or thing (p. 114). Either the "objects" of these perceptions are the same properties that can also be ascribed in thought and belief to physical objects, or else they are not perceptions of the same properties that it is intelligible to think of physical objects as having (p. 116). According to this second indirect view, in thinking that physical objects are coloured, the properties we ascribe to those objects are not the properties we see when we see colours (p. 117). According to Stroud, a proponent of the indirect view has to embrace the implausible position that yellow in Jones sees yellow means something different from its occurrence in Jones sees a lemon to be yellow (pp. 103-17). Specifically, the first occurrence picks out the perceived property that physical objects cannot have, and the second occurrence picks out the disposition that physical objects can have. However, it is quite unclear why the indirect theorist must agree. Offhand, she could suppose that ordinary talk completely ignores these perceived properties that physical objects cannot have. And in any case the source of the indirect view is a bit of a mystery. Stroud seems to have Peacocke in mind (see p. 119. and p. 162, fn. 9), but Peacocke himself would not characterize his position in these unfriendly terms.
In his examination of the error theory, Stroud considers at length the traditional argument that objects have no colours because colour properties are not required to explain our perceptionsonly physical properties are. One response is simply to claim that colours are physical properties. A rather striking lacuna in Strouds book is the omission of this viewat any rate in its contemporary versions (see, for example, David Hilbert, Color and Color Perception, CSLI, Stanford, 1987; and Frank Jackson, The Primary Quality View of Color, Philosophical Perspectives 10, 199-219, 1996). Perhaps he thinks it obviously false, or unintelligible, but we arent told. Anyway, Stroud does make the excellent point that the arguments proponent must have found, somehow, a place in reality for our perceptions of colour, for these are the things that are supposed to be explained (p. 80). Stroud links this point with his master argument against the error theory.
The master argument tries to show that it [is] a necessary condition of our acknowledging the presence in the world of perceptions of and beliefs about the colours of things that we believe that some objects are coloured (p. 157). If correct, this is an astonishingly strong result. It would show that error theorists who were not also eliminativists about color-psychology have an unstable position: one could not rationally maintain that people have colour perceptions and beliefs without affirming that some objects are coloured. Stroud does not pretend to offer a conclusive proof (p. 157), but does think he has a very strong case (p. 149). The argument, as Stroud says, is Davidson-inspired. The basic claim is that if I am to interpret another as having a perception of yellow or as believing that lemons are yellow, I cannot identify the property in question (p. 158) unless I myself believe that some (material) objects are (were?) yellow. The colour realist can identify the property thus: I know what perceptions of yellow are because I know what yellow is. It is the colour of yellow objects. I believe that many objects are yellow (p. 160). But if this is deemed adequate, I do not see why the error theorist cannot identify the property in a similar fashion: I know what perceptions of yellow are because I know what yellow is. It is the colour that lemons appear to have. By the way, I do not believe that any objects are yellow.
Suppose, though, that Stroud is right: colours are not secondary qualities, and the error theory is incoherent in the way explained. One might think the quest for reality has ended in a pretty satisfactory fashion: the most promising way of being a colour subjectivist doesnt work, and there is no good argument against the testimony of our senses that objects are coloured. Colours, we may fairly conclude, are real and objective. Anyone familiar with Strouds work on scepticism will doubt that matters could be this simple, and so it proves.
Stroud admits there is a temptation to conclude that objects really are coloured after all, but says that this is worth resisting (p. 192). On the next page, however, Stroud says that he does not mean to suggest that perhaps those beliefs [that lemons are yellow, etc.] are not true or that there is reason to doubt them (p. 193). Indeed, Stroud asserts that lemons are yellow, and that we do know that objects are coloured (p. 205, my italics). So why hasnt Stroud just succumbed to the temptation that he claims must be resisted?
Im not confident of the answer, but it is evidently connected with the master arguments limitations. The master argument only purports to show that if one of the error theorists premises is acceptable, then her conclusion must be rejected; and it doesnt follow from this that her conclusion is false. So, despite the fact that we have an assurance...in everyday life that objects are coloured, we cannot say that the answer to the metaphysical question is: Yes. Objects are really coloured (p. 208). If we foist on Stroud the view that the metaphysical question is simply the everyday question with much higher standards attached, then he is saying that although we know that objects are coloured, we do not have an incontrovertible proof that they are, which is disappointing (p. 209).
This interpretation of Stroud may well be incorrect, however. First, it is difficult to see why the lack of an incontrovertible proof is at all disappointing, given that only someone overimpressed with the power of philosophy would expect otherwise. Second, the interpretation fits poorly with other formulations of the disappointing upshot, for instance that we do not have the right kind of understanding of our position in the world (p. 209). If the disappointment were due to the missing incontrovertible proof, this remark would be misplaced. Incontrovertible proofs are not requiredI hope!in order to achieve a philosophically satisfying understanding of what the world is really like.
So there is much to dispute in Strouds book. However, this should not obscure the fact that it is an admirable contribution to metaphysics.
Massachusetts Institute of Technology
 Thanks to Martin Jones, Sarah McGrath, Susanna Siegel, and Robert Stalnaker.