 McGrew is not alone in holding that experiential or phenomenal features can, by virtue of our direct awareness of them, constitute the content of a special class of concepts. Gertler (2001, 2011, 2012), Chalmers (2003, 2010), and Nida-Rümelin (2004) defend views very much in the same spirit. Gertler (2001) distinguishes between ordinary demonstratives, which typically involve an intention to pick out an entity that satisfies some description, and a pure demonstrative, which picks out its referent solely by a fundamental act of attention or acquaintance. Chalmers (2003, 2010) defends a similar view according to which some noninferential beliefs are justified by virtue of involving a “direct phenomenal concept,” a concept whose content is constituted by a phenomenal quality with which one is acquainted. The view is supported by considering Frank Jackson’s (1982) hypothetical case of Mary, who has learned all of the physical facts about color but has never had a visual experience in color until one day she experiences red. Jackson argues there that Mary thereby learns some new information; she acquires some new knowledge. And since Mary already knows all the physical facts about color, this new item of knowledge must, Jackson argues, be of a non-physical fact. Chalmers (2010) and Nida-Rümelin (2004) argue that it is difficult to make sense of the epistemic progress of subjects like Jackson’s Mary unless we accept that there is a core phenomenal concept whose content is constituted by an underlying phenomenal or experiential quality with which the subject is acquainted. Chalmers (2004) relies on the acquaintance approach to phenomenal concepts to defend the knowledge argument for dualism—i.e., the claim that Mary acquires new knowledge, and that this must be knowledge of a non-physical fact. (He notes (2003: 227) that demonstratives are naturally used to express direct phenomenal concepts (e.g., “I am experiencing this quality”), and that there may be a sense in which a direct phenomenal concept is a “demonstrative” concept, but he avoids such a label at least in part because of the danger of confusing direct phenomenal concepts with demonstrative ones as usually understood.) It is worth noting that, in contrast, some philosophers appeal to knowledge by acquaintance to make sense of Mary’s new knowledge in order to oppose, rather than to support, the success of the knowledge argument for a dualistic conclusion (e.g., Conee 1994 and Balog 2012). 