Appearance-profile fixation and twin-earth arguments against high-levelism

Abstract

High-levelism about perceptual experience holds that experience presents not only low-level features such as colour and shape, but also high-level properties such as natural and artefact kinds. Twin-Earth-style arguments are widely taken to threaten this liberal view: they are supposed to show that Twin-Earth cases involve only low- or mid-level ‘looks’, rather than differences in kind-representing phenomenology. A familiar high-levelist reply weakens the link between phenomenal character and phenomenal content, allowing phenomenal duplicates to differ in which high-level properties they represent. In this paper, I argue that this argument tacitly relies on a bridging principle I call Appearance-Profile Fixation (APF): sameness of a coarse, image-based appearance profile suffices for sameness of high-level phenomenology. First, I reconstruct Twin-Earth arguments so as to make APF explicit and motivate it by appeal to the gist literature in vision science. Second, drawing on a Structural-Fit Lemma for phenomenal spaces and a ‘fake pine’ case, I show that APF is hard to reconcile with robust forms of high-levelism even on a weak notion of phenomenal content. Third, using high-levelists’ own interpretations of bistable displays, Mooney faces, rapid-scene categorisation, and appearance-matched metamers, I argue that high-level phenomenology can vary while the relevant appearance profile is held fixed. The upshot is that the dialectical force of Twin-Earth arguments against high-levelism depends on a substantive, yet optional, thesis about cross-world phenomenal pairing that high-levelists have independent reason to reject.