  Part, but only a part, of Ayer’s reason for embracing such indirect realism was what has been called the argument from illusion, the central idea of which is that, for any perceptual state of ours, we could be in a state indiscriminable from it but which did not involve perception of any material object or scene, it being an illusion that there was any such object or scene to be perceived. That is, non-veridical perceptions could share their intrinsic properties with veridical perceptions, this possibility leading Ayer to claim that it was plausible that the object of perception in both cases was (non-material) experience, and not, as naïve realism would have it, the physical objects themselves. As a consequence, ordinary perceptual judgments, those making claims about such objects, go beyond what is ‘strictly available’ in our perceptual experience, and so they form a theory about that which is available to perception.