  A further question to be asked in this context is whether the disjunctivist should treat all cases of illusion as equivalent to cases of partial hallucination. For example, if a subject perceives a green object that looks to her to be blue, should the disjunctivist say that the subject is perceiving the object but hallucinating the blueness it seems to possess? Brewer (2008) offers a disjunctivist account of certain illusions that he thinks need not be treated as cases of partial hallucination (e.g., the Mueller-Lyer illusion). According to Brewer, such illusions are simply cases in which the direct object of experience has visually relevant similarities with paradigms of a kind of which it is not in fact an instance. The fact that the direct object of perception looks F, but isn’t, is explained in terms of the idea that the object may intelligibly be taken to be F, when seen from the point of view in question, in the relevant circumstances of perception, in virtue of its relevant similarities with certain paradigm Fs. In the case of certain illusions, when an object looks to be a certain way that it isn’t, a disjunctivist might place emphasis on the idea that this misleading appearance is publicly observable; for instance, it might be the sort of thing one is able to photograph. The disjunctivist might then say that in such cases we can ascribe to the seen object a publicly observable feature—a ‘look’ or ‘appearance property’ that the object has. When one sees the object one may be visually aware of this appearance property—its having the look of an F. And one’s awareness of this appearance property may intelligibly mislead one into mistakenly judging the object to be F. (For related proposals about perceptual illusions, but which differ from Brewer’s account in important respects, see Antony 2011 and Genone 2014. For defence of the claim that empirically grounded models of illusion may be congenial to naïve realism, see Phillips 2016.) 