This study sought to discover what critical apparatus would be most appropriate for observers of verbal discourse who choose to accept Aristotelian or "information theory" causal accounts of dynamic process. The major conclusions were: (1) Both causal systems employ a static grid to express relationships; but while the Aristotelian relations are generic, the information theorist is limited to correlating perceived structural similarities among message components. (2) Both types of critic will seek an objective, analytical orientation for discussing rhetorical discourse; but whereas the Aristotelian investigates the motivational aspects of human communication, the information theorist assesses the persistence of structural characteristics through time. The comparison of causal notions in these two theories illuminates the influence of causation upon the theory and pracitce of rhetorical criticism. (DI)