Argues that 19th-century "declarative"/"reiterative" rhetoric derives theoretical authorization from the 82nd "Athenaum Fragment" of Friedrich Schlegel. Analyzes content and rhetorical structure of Schlegel's polemical/reiterative rejection of "philosophical and scientific demonstration." Discusses the rhetorical efficacy of reiterative rhetoric and relevance of Schlegel's attack on demonstration to recent attempts to rehabilitate sophistic rhetorical theory and declarative rhetoric. (PA)