Abstract: Seeing, Doing, and Knowing is a philosophical framework for thinking about sensory systems as active devices for data extraction B rather than, in the traditional way, as passive recorders of ambient energy patterns.Sensory systems are automatic sorting machines that assign real-world objects to classes. A sense feature is the property of belonging to such a class. A sensory experience, or sensation, is a label that the system uses in order to allow the organism access to the classifications that it has performed. This Sensory Classification Thesis (SCT), discussed in Chs 1–3, inverts the normally assumed relationship between sensory classes and sensations. Philosophers standardly hold that red is to be defined in terms of the sensation of red; here, sensations derive from sensory classes and are thus unsuitable for defining them. SCT is a simplification: some sensory systems order real-world objects in relations of similarity, and do not just put them into discrete classes (Chs 4–5).SCT makes sense of sensory specialization across species—different kinds of organisms employ different classification schemes to serve their idiosyncratic data-extraction needs (Chs 6–8). This leads to an output-driven account of sensory content. Sense features are defined in terms of their aptness for epistemic (not just sensorimotor) actions, and the content of sensations in terms of the features with which they are associated by an internal convention (Chs 9–11). This leads to a form of realism: sensory classifications are correct if the states of affairs in which they consistently occur are indeed right for the actions with which they are paired.Finally, the nature of object perception is explored: Chs 12–13 speculate about the psychological origins of sensory reference and of the feeling in perception that external objects are present (by contrast, for instance, with objects depicted in paintings and photographs).

Keywords: classification, coevolution, object perception., perception, perception and action, perception and knowledge, perceptual content, realism, reference, sensation, sensory specialization, similarity