Abstract
§1 The Disjunctive Conception of Experience Descartes was surely right that while normal waking experience, dreams and hallucinations are characteristically distinguished at a purely phenomenological level, — by contrasts of spatial perspective, coherence, clarity of image, etc., — it is not essential that they be so.1 What is it like for someone who dreams that he is sitting, clothed in his dressing gown, in front of his fire can in principle be subjectively indistinguishable from what it is like to perceive that one is doing so, fully conscious and awake. The same holds for multi-sense hallucination and, it is assumed, would hold of the experience of an envatted brain in the usual postulated scenario. This thought — that normal perceptual experience allows in principle of perfect phenomenological counterfeit — is, to the best of my knowledge, nowhere seriously challenged in John McDowell's writings.2 What he rejects is an idea that builds upon and would be potentially explanatory of it: the Lockean idea that, as far as the states enjoyed by the experiencing subject are concerned, there is actually no generic distinction between dream, hallucination, and wakeful perception: — that one and the same type of state of consciousness is involved in all three cases, and that which (if any) of the three a particular occurrence of the type falls under is a matter of how it is caused. On this model, the distinction between Descartes' notional fully lucid dream and the corresponding raft of perceptions of his dressing-gowned, sedentary state is like that between a certain kind of sunburn and nettle rash. For Disjunctivism, however, the Lockean — as McDowell likes to say, “Highest Common Factor” — conception of perceptual experience and its potential counterfeits is a conceptual error. There is no single type of state of consciousness present in each of dreaming, perceiving and hallucinating, whose instances fall under one or other of those characterisations purely by virtue of their aetiology..