Argument and Authority in the Visual Representations of Science

The focus of workplace communication research on visual rhetoric has tended to be the efficient and unproblematically "effective" functioning of visual texts. By suggesting ways in which the visual representations of science are construed by expert readers, this article responds to a call within our discipline for more critically focused contributions to the study of visual literacy. A former editor-in-chief of the American Journal of Botany was asked to explain his interpretation of visuals appearing over an 80-year period in that journal; his responses illustrate how visual explanations testify to their creators' authority and how, once established, such authority actuates the rational arguments of science. Rhetorical appeals within and arrangement of visual texts are considered, as is the persuasive power of legends and captions.