This study is an unconventional treatment of an ancient problem - the relationship between vision and painting. Dr Hyman examines both the role that the concept of a picture has played in ancient and modern visual theory, and the influence of visual theory on theorists and historians of art from Plato to Gombrich. However, this book is not primarily an essay in the history of ideas: its chief purpose is to root out certain philosophical confusions that are embedded in the historiography of Western art, and then to examine afresh the invention of artificial perspective in 15th-century Florence and the inception of naturalism in 5th-century Athens.