Each chapter includes a case study to demonstrate its particular rhetorical function (religious stained glass, the photograph “Saigon Execution,” and electoral maps and their parodies). The underlying purpose of each chapter and its case study is to illuminate its attendant rhetorical function and demonstrate how one might take it up as a heuristic to make sense of other cases as well as distinguish similar but distinct functions.
As we began to elaborate the rhetorical functions of the visual as a means of helping diversify visual rhetoric’s depth of field, we started with these three functions because we consistently found them at work within existing visual rhetoric scholarship.
While the specific foci and theoretical commitments of that existing work has varied widely, we also found a fair amount of consistency at the meta level (what we might call its depth of field), in terms of how visual rhetoric scholars have imagined the nature and force of rhetoric itself. The rhetorical functions of pictures, images, and the visual as imagined in this scholarship have tended to live in the civic realm, have most often been matters of direct engagement (persuasion qua persuasion), and have typically imagined intention and agency on the part of both viewers and image-makers. They are, in other words, relatively traditional rhetorical functions that resonate with the realms of public speech and writing out of which the Western study of rhetoric historically emerged.
Visual rhetoric’s typical frames are enticingly resonant with the three traditional “branches” of rhetoric introduced by Greek rhetoricians, seemingly grown from long standing rhetorical interest in the art of making policy, adjudicating conflict, and sustaining civic life. While the first three functions are not precisely deliberative, forensic, and epideictic, they echo those traditional concerns. The pedagogical function of the visual treated in chapter 1 carries notes of deliberation; the catalytic force of the visual identified in chapter 2 is markedly forensic; and the communal functions discussed in chapter 3 have a great deal in common with the rhetorical functions of the epideictic. It is not surprising that the most commonly treated rhetorical functions of the visual would echo the traditional branches of rhetoric—they loom large in rhetorical studies in general.
The three rhetorical functions of part I belong together, however, not because of their shared presence in existing scholarship or their shared resonance with traditional rhetorical functions but because of the factors at the root of both that presence and resonance: an understanding of rhetoric that is rooted in the public, focused on persuasive intent, and most frequently found in material, identifiable visual objects.
