 Qualitative properties and phenomenal features of mental states are each often called “qualia” (singular, “quale”). In recent philosophy of mind that term has been used in a number of confusingly different ways. There is a specific, fairly strict sense that comes to us from C.I. Lewis (1929) by way of Goodman (1951) (though there is plenty of room for exegetical disagreement about Lewis’ own usage). A quale in this sense is a qualitative property inhering in a sensory state: the color of an after-image, or that of a more ordinary patch in one’s visual field; the pitch or volume or timbre of a subjectively heard sound; the smell of an odor; a particular taste; the perceived texture of an object encountered by touch. (The term “inhering in” in the preceding sentence is deliberately vague, and neutral on as many metaphysical issues as possible. In particular, qualia may be properties of the experiences in which they inhere, or they may be related to those experiences in some other way.) For reasons that will become clear, we may call this sense of “qualia” the “first-order” sense. Notice that it differs from the broader and vaguer sense defined in the entry on  qualia  (“the introspectively accessible, phenomenal aspects of our mental lives”), and from the much more heavily laden sense of Block (1990, 1995, 1996), according to which “qualia” are by stipulative definition neither functional nor intentional properties. To avoid further confusion, let us speak of sensory qualities.