Irvin Rock was a global perceptual theorist in the grand tradition of Helmholtz, Wertheimer, and Gibson. This posthumous volume, the culmination of a long and distinguished career, brings together an original essay by the author with a careful selection of previously published articles (many by or co-authored by Rock) on the theory that perception is an indirect process in which visual experience is derived by inference, rather than being directly and independently determined by retinal stimulation.

Rock's reasons for holding that perception is indirect were mainly empirical. Unlike many theorists, he paid close attention to a broad range of experimental evidence in evaluating theoretical claims. His approach, in which theory and experiment go hand in hand, is well represented in this book.