John K.G. Shearman 
Only Connect [PDF ebook] 
Art and the Spectator in the Italian Renaissance

A leading art historian’s plea for a more engaged reading of Italian Renaissance art
Only Connect constructs a history of Renaissance paintings and sculptures that are by design completed outside themselves by the spectator, that draw the spectator into their narrative plot or aesthetic functioning, and that reposition the spectator imaginatively or in time and space. John Shearman’s concern is mostly with anterior relationships with the viewer—that is, relationships conceived and constructed as part of a work’s design, making, and positioning. He proposes unconventional ways in which works of art may be distinguished from one another, and in which spectators may be distinguished as well, and enlarges the accepted field of artistic invention.
Only Connect challenges us to recognize the presuppositions of Renaissance artists about their viewers, shining a light on the process of discovery by some of the most inventive and intellectual artists of the period.