Photography matters, writes Jerry Thompson, because of how it works -- not only as an artistic medium but also as a way of knowing. With this provocative observation, Thompson begins a wide-ranging and lucid meditation on why photography is unique among the picture-making arts. He constructs an argument that moves with natural logic from Thomas Pynchon (and why we read him for his vision and not his command of miscellaneous facts) to Jonathan Swift to Plato to Emily Dickinson (who wrote "Tell all the Truth but tell it slant") to detailed readings of photographs by Eugène Atget, Garry Winogrand, Marcia Due, Walker Evans, and Robert Frank. Forcefully and persuasively, he argues for photography as a medium whose business is not constructing fantasies pleasing to the eye or imagination, but describing the world in the toughest and deepest way.