In 1978 I published an essay called "The Senses of Rhetoric: A Topical System for Critics," in the Central States Speech Journal as it was then called--it is now called Communication Studies. In that essay I attempted to articulate some starting points for the rhetorical analysis of texts in a variety of media and genres, both political and cultural. The idea of the topical approach was to permit theoretical rigor without invoking categorical blindness, a problem at the core of the rhetorical tradition. In the rhetorical tradition, a topic is a place where arguments and ideas may be found, a starting point for the process of invention. These places are sometimes "commonplaces" of tacit cultural knowledge, sometimes analytical promptings.
Thomas W. Benson. "The Senses of Rhetoric: A Topical System for Critics." Central States Speech Journal 29 (1978): 237-250.