Perceptual Content is the first book to discuss and compare the representational characters of all the traditional 'five senses'. It has three main topics or concerns. (1) The diversity of the senses: though Lycan maintains as a working assumption that all perception represents, the similarity between sense modalities ends there. The senses' respective representational modes, styles and structures -- not just their mechanisms -- differ very strongly from each other. (2) The Layering thesis: Lycan argues that a single sensory representation usually has more than one content, the contents systematically related to each other by a priority or dependence relation. More specifically, a perceptual state may represent one object or property by representing a more primitive or less ambitious one; he calls this the 'layering' of content. For example, by hearing a sound sequence involving such-and-such volumes and timbres, you hear a voice speaking, and by hearing the voice, you hear words in a