  Different disjunctivists group together perceptions, illusions and hallucinations in different ways when offering their disjunctive characterisations of perceptual experience. At points it looks as though Hinton is suggesting that illusions can be grouped together with veridical perceptions. For in certain places he says that his Perception-Illusion disjunctions permit a description of what is seen in terms of how the thing looks, thereby allowing the following kind of Perception-Illusion disjunction: ‘S sees something which looks blue or is having that illusion’ (1973, 61). In other places he says things that suggest that the illusion of an object appearing blue should not be grouped together with veridical perception, for he says that an experience as of blue is equivalent to the mere disjunction ‘Either I actually see an optical object that is blue in colour, or I am in some situation… that is to me like that one’ (1967b, 12). Snowdon groups together perceptions and illusions in his disjunctive characterisation of experience: ‘Either (there is something which looks to S to be F) or (it is to S as if there is something which looks to S to be F)’. In contrast, McDowell, in his appeal to the idea of facts being made perceptually manifest, appears to group together illusions and hallucinations: an appearance that such-and-such is the case can be ‘either a mere appearance or the fact that such-and-such is the case making itself perceptually manifest to someone’.