Online research in philosophy

Teleological theories of content are thought to suffer from two related difficulties. According to the problem of indeterminacy, biological function is indeterminate in the sense that, in the case of two competing interpretations of the function of an evolved mechanism, there is often no fact of the matter capable of determining which function is the correct one. Therefore, any attempts to construct content out of biological function entail the indeterminacy of content. According to the problem of transparency, statements of biological function are transparent in that a statement of the form 'the function of evolved mechanism M is to represent Fs' can be substituted salva veritate by a statement of the form 'the function of evolved mechanism M is to represent Gs' provided that the statement 'F iff G' is counterfactual supporting. Therefore, any attempt to construct content out of biological function must fail to capture the intensionality of psychological ascriptions. This paper argues that the teleological account is undermined by neither of these problems. Failure to appreciate this point stems from a conflation of two types of proper function - organismic and algorithmic - possessed by an evolved mechanism. These functions underwrite attributions of content to distinct objects. The algorithmic proper function of a mechanism underwrites attributions of content to the mechanism itself, while the organismic proper function of a mechanism underwrites attribution of content to the organism that possesses the mechanism. However the problems of indeterminacy and transparency arise only if the attributions of content attach to the same object.

There are perceptual states whose representational content cannot even in principle be conceptual. If that claim is true, then at least some perceptual states have content whose semantic structure and psychological function are essentially distinct from the structure and function of conceptual content. Furthermore the intrinsically “orientable” spatial character of essentially non-conceptual content entails not only that all perceptual states contain non-conceptual content in this essentially distinct sense, but also that consciousness goes all the way down into so-called unconscious or subpersonal mental states. Both my argument for the existence of essentially non-conceptual content and my theory of its structure and function have a Kantian provenance.

The 'content view', in slogan form, is 'Perceptual experiences have representational content'. I explain why the content view should be reformulated to remove any reference to 'experiences'. I then argue, against Bill Brewer, Charles Travis and others, that the content view is true. One corollary of the discussion is that the content of perception is relatively thin (confined, in the visual case, to roughly the output of 'mid-level' vision). Finally, I argue (briefly) that the opponents of the content view are partially vindicated, because perceptual error is due to false belief.

The notion of perceptual content is commonly introduced in the analysis of perception. It stems from an analogy between perception and propositional attitudes. Both kinds of mental states, it is thought, have conditions of satisfaction. I try to show that on the most plausible account of perceptual content, it does not determine the conditions under which perceptual experience is veridical. Moreover, perceptual content must be bipolar (capable of being correct and capable of being incorrect), whereas perception as a mental state is not (if it is veridical, it is essentially so). This has profound consequences for the epistemological view that perception is a source of knowledge. I sktech a two-level epistemology which is consistent with this view. I conclude that the analogy between perception and propositional attitudes, from which the notion of perceptual content is born, may be more misleading than it is usually thought.

Clearly we can perceive both objects, and various aspects or appearances of those objects. But how should that complexity of perceptual content be explained or analyzed? I argue that perceptual representations normally have a double or two level nested structure of content, so as to adequately incorporate information both about contextual aspects Y(X) of an object X, and about the object X itself. On this double content (DC) view, perceptual processing starts with aspectual data Y?(X?) as a higher level of content, which data does not itself provide lower level X-related content, but only an aspectually encoded form of such data. Hence the relevant perceptual data Y?(X?) must be.

I argue that perceptual content involves representations both of aspects of objects, and of objects themselves, whether at the level of conscious perception, or of low-level perceptual processing - a double content structure. I present an 'orientational' theory of the relations of the two kinds of perceptual content, which can accommodate both the general semantic possibility of perceptual misrepresentation, and also species of it involving characteristic perceptual confusions of aspectual and intrinsic content. The resulting theoretical structure is argued to be a broadly methodological or logical one, rather than a substantive theory that is open to empirical refutation.

b>. Computational models of colour vision assume that the biological function of colour vision is to detect surface reflectance. Some philosophers invoke these models as a basis for 'externalism' about perceptual content (content is distal) and 'objectivism' about colour (colour is surface reflectance). In an earlier article (Thompson et al. 1992), I criticized the 'computational objectivist' position on the basis of comparative colour vision: There are fundmental differences among the colour vision of animals and these differences do not converge on the detection of any single type of environmental property. David R. Hilbert (1992) has recently defended computational objectivism against my 'comparative argument;' his arguments are based on the externalist approach to perceptual content originally developed by Mohan Matthen (1988) and on the computationally inspired theory of the evolutionary basis for trichromacy developed by Roger N. Shepard (1990). The present article provides a reply to Hilbert with extensive criticism of both Matthen's and Shepard's theories. I argue that the biological function of colour vision is not to detect surface reflectance, but to provide a set of perceptual categories that can apply to objects in a stable way in a variety of conditions. Comparative research indicates that both the perceptual categories and the distal stimuli will differ according to the animal and its visual ecology; therefore externalism and objectivism must be rejected.

In virtue of what does a representational state have the content it does? Several philosophers have recently proposed that a representational state gets its content from its biological function. After explaining the sense of biological function used in these views, I criticise the proposal. I argue that biological function only determines representational content up to extensional equivalence. I maintain that this holds even if biological function is defined in terms of an intensional notion like Sober's "selection for".

Abstract This paper proposes that pictures are functional objects which figure in norm?governed practices of usage yet whose specific function is to present the world as it looks to acculturated perceivers. Pictorial content presents the way the world looks to a subject's acculturated perceptual grasp. Hence, pictorial content needs to be explained in terms of a theory of perceptual content, but a novel theory which departs from the two?stage sensation?based approach to perception and the polarization between naturalism and conventionalism that it engenders. Following a diagnosis of this polarization, I invoke a novel theory of perception that explains perceptual content as conceptually articulated and determinate in character. I show that (1) pictures present content of the same distinctive determinate type as perceptual content; and that (2) pictures do so by invoking perceptual experience and perceptual processes that are of the same kind as those invoked by actual scenes. This perceptualist approach considers and explains the role of norms as well as of the nature of our visual processes, allowing us to allocate the insights of both conventionalism and naturalism to their proper theoretical roles.