In ‘Of Sensory Systems and the “Aboutness” of Mental States’, Kathleen Akins (1996) argues against what she calls ‘the traditional view’ about sensory systems, according to which they are detectors of features in the environment outside the organism. As an antidote, she considers the case of thermoreception, a system whose sensors send signals about how things stand with themselves and their immediate dermal surround (a ‘narcissistic’ sensory system); and she closes by suggesting that the signals from many sensory systems (...) may not in any familiar sense be about anything at all. Her presentation of the issues, however, overlooks resources available to ‘the traditional view’—or so I shall argue. Akins’s own thumbnail sketch of what is wrong with the traditional view is that it asks, concerning a given sensory system, ‘what is it detecting?’, when we should instead be asking ‘what is it doing?’ (352). Her point is that on the traditional view the function of a sensory system—what it's ‘for’—is to detect or indicate (values of) features of the outside environment. But at least on one version of the traditional view—namely Ruth Millikan’s—this would never be the sole or main proper function of a sensory system. (Akins does not list Millikan as a traditionalist, but Millikan fits squarely Akins’s description of them, since she believes in a naturalistic theory of aboutness and thinks it should begin with the senses.) For Millikan (1989, 1993), the proper function of a sensory system is in the first instance enabling behavioural systems—in the simplest case, motor routines—to perform their proper function. This they do, roughly, by switching on and steering the behavioural routines. Where features of the outside environment come in is as Normal (= assumed-by-the-design) conditions for the successful performance of the sensory system's proper function. That is, the only strategy for switching on and steering that is simple enough for evolution to have hit upon it, and reliable enough for evolution to have liked it, is a strategy which gears the steering to (values of) features of the outside environment. But as soon as one starts fleshing out the details of this story, one notices that they are probably quite different in the case of thermoreception from how they are with ‘distance’ senses such as vision and olfaction--a point which Akins overlooks.. (shrink)

I argue for sensory pluralism. This is the view that there are many forms of sensory interaction and unity, and no single category that classifies them all. In other words, sensory interactions do not form a single natural kind. This view suggests that how we classify sensory systems (and the experiences they generate) partly depends on our explanatory purposes. I begin with a detailed discussion of the issue as it arises for our understanding of thermal perception, followed by a general (...) account and defense of sensory pluralism. (shrink)