 However, this use of introspection is of limited value when it comes to addressing certain philosophical controversies. One such controversy in the philosophy of perception is whether visual perceptual experiences have “rich contents”. According to a rich content view, visual experiences can and often do present the instantiation in perceptual awareness not just of lower-level physical properties such as colors, shapes, illumination, and motion, but also such experiences can and typically do also present the instantiation of higher-level properties including, for instance, properties that categorize objects (cars, cacti, clouds), actions (starting a car, planting a cactus, pointing to a cloud) and causal relations. But as Susanna Siegel (2011: chap. 3), a defender of the rich content view, points out, the controversy over this view cannot be settled by the direct use of introspection; one cannot reliably tell just by attending carefully to one’s visual experience whether its perceptual contents are rich. But this does not mean that introspection is of no use. Rather, it figures importantly in phenomenal contrast arguments. There is a variety of such arguments that differ importantly in their probative power that need not concern us  here.[7]  Generally speaking, such arguments draw a conclusion about the phenomenal character of a certain type of experience, by appealing to a phenomenal difference of some sort between two experiences being compared. For example, in defending the claim that visual experiences present one with object kinds, Siegel contrasts one’s visual experience of pine trees, situated among other trees in a forest, before acquiring the disposition to easily recognize pine trees, with one’s visual experience of the forest after acquiring the disposition. Siegel points to a “feeling of familiarity” in one’s overall phenomenology in the second experience that is salient to introspection. This introspectable difference figures in a premise in an abductive argument (i.e., inference to the best explanation) for the claim that one’s visual experience after gaining the appropriate recognitional disposition includes the presentation of pine tree, an instance supporting the rich content view, which then generalizes to a wide range of visual experiences. Introspection plays an ineliminable role in phenomenal contrast arguments. However, at least as employed by Siegel in defending the rich content view, its use is to reveal something reliably detectable about one’s contrasting experiences, which can then provide the basis for an argument to a conclusion about phenomenal character.