Adverbialist perceptual theories

Direct realists reject the act-object analysis of perceptual experiences advanced by sense-datum theorists and other indirect realists. According to most early direct realists (e.g., Ducasse 1952, Sellars 1975), even when visually hallucinating a red apple on the table, one does not directly see a private mental particular or a constellation of mental qualities; rather one is having a visual experience that is like an experience which is normally brought about when one actually sees a real red apple on the table. Direct realists, in other words, typically insist that such cases should not be analyzed in terms of a perceiver standing in a certain perceptual relation to a private mental object or quality. Rather the analysis involves only one particular, the perceiver herself, and her being in certain sorts of (perceptual, experiential) states or conditions that are typically brought about under certain circumstances in which one genuinely perceives something. In standard cases, when one is having a veridical perception, the experiential state of the perceiver is brought about by the actual object of her perception, and the perceiver’s state is qualitatively differentiated by the causal influences of the sensible qualities of the public object. In nonstandard cases like in hallucinations and illusions, phenomenologically the same kinds of states are brought about by different causal routes, and the qualitative differentiation of one’s experiential state in such non-veridical cases is the result of deviant causal influences. (Pitcher 1970, p. 384)

This sort of analysis of experiences is sometimes known as adverbialism in the literature because in perceiving a red object one is said to be in a state of perceiving something “red-ly.” The theoretical import of this way of talking is that perceiving something that is red is a manner of perceiving that object that would be distinct from the manner of perceiving it if the object were blue, in which case one would be perceiving it “blue-ly.” Similarly when one hallucinates a red object, there is only one object, the perceiver who is sensing in a certain manner, namely, red-ly. In other words, ‘red’ is said to qualify not a private object but rather a state or activity of a person, that state being a manner of perceiving or sensing physical objects that are red.^[11] For our purposes, keeping up with the general naturalistic motivation behind developing direct realist views, we can take adverbialism as an attempt to get rid of mysterious mental objects or qualities in favor of metaphysically less costly states or activities of persons or manners of perceiving that qualify persons qua subjects of experience. So a pain experience, for a direct realist, is a specific manner in which tissue damage is (somatosensorially) perceived in a bodily region. When we report pain, we report the occurrence of experiences understood this way — adverbially.

Adverbialism of this sort can be effectively combined with intentionalism or representationalism about experience (for more on the connection between adverbialism and representationalism, see Kraut 1982). An adverbialist has to somehow characterize these ways or manners of sensing/perceiving for distinguishing between them, and a natural way to do that is by appealing to the standard or canonical conditions under which those perceptual events are brought about (recall how direct realists want to handle a visual hallucination: one is having a visual experience that is like an experience which is normally brought about when one actually sees a real red apple on the table). Thus it may be reasonable to argue that those canonical conditions are what the specific perceptual events or activities of the persons represent. For instance, it is plausible to claim that a specific perceptual activity constitutes the perception of red (= the perceptual event representing the instantiation of red) because it is the kind of psychological event regularly (canonically) caused by red surfaces — indeed one might expect that the psychophysics of sensory modalities would detail these canonical or standard conditions in objective terms. Although this maneuver is open to direct realists, it is optional. When one takes this option the result is pretty much a strong form of representationalism — for which see next section.

There are various technical difficulties with adverbialism, especially when dealing with phenomenologically complex overall experiences such as having three pains of different qualitative character simultaneously occurring in three different locations in one’s body. It is not clear whether adverbialist approaches can successfully tie the appropriate manners corresponding to different qualities with the right pains or tissue damage on different locations. (See Jackson 1975, 1977 for a detailed criticism of this sort; Tye 1996, pp. 74-77, contains a useful summary.) Furthermore, even when one might successfully get rid of mysterious mental objects like sense-data with this adverbialist move, it is not clear whether adverbialism might still lead to a form of property dualism according to which one is directly aware of certain (non-physical) phenomenological qualities instantiated by experiences realized by brain states. These qualities seem to be required to explain how the manners of different perceptual activities of a perceiver could be differentiated.

There are other sources of resistance to direct perceptual theories of pain and other intransitive bodily sensations. Some objections stem from considerations about whether direct perceptual theories can give adequate accounts of perception in general, so are not specific to their treatment of pain. One of the most frequently discussed worries about direct perceptual theories in general is whether they can do justice to the internalist intuition that perceptual experience is phenomenally rich in a way that cannot be pushed back to the extramental world. In the case of early direct realist like Armstrong and Pitcher, this worry is even more pressing since they were cognitivist about perceptual experience in general; that is, they attempted to explain perception in terms of belief acquisition (or, in terms of acquisition of belief-like cognitive states). But beliefs don’t seem to have the right kind of phenomenology associated with perceptual experiences and bodily sensations (see Everitt 1988 and Grahek 1991 for this kind of criticism). As pointed out earlier, early direct realists played down the importance of experiential phenomenology and sometimes even denied its existence fearing that acknowledging it will lead to the introduction of sense-data or “irreducibly psychic” qualia.^[12] But this qualiaphobia drove many away from the early direct perceptual theories (especially those who were not much worried about skepticism and epistemology in general) with the conviction that these theories are not adequate after all for capturing the rich phenomenology of perceptual experiences.