The introduction is an overview of theories of allegory and develops a model of allegory based on the works of Charles Sanders Peirce, Walter Benjamin, and sundry postmodern critics. The chapter argues that no critical study of allegory operating at the level of form in postmodern poetry currently exists, and that formal allegory is a distinguishing feature of innovative poetry written after World War II. It devises a means for using Peirce’s tripartite division of the sign into index, icon, and symbol as a template for understanding historical shifts in prosody. It ends by examining surrealist, structuralist, and post-structuralist discussions of collage, montage, and allegory.