Scientific articles exemplify standard functional units constraining argumentative structures. Severe space limitations demand every paragraph and illustration contribute to establishing the paper's claims. Philosophical testing and confirmation models should take into account each paragraph, table, and illustration. Hypothetico-Deductive, Bayesian Inductive, and Inference-to-the-Best-Explanation models do not, garbling the logic of papers. Micro-analysis of the fundamental paper in plate tectonics reveals an argumentative structure commonplace in science but ignored by standard philosophical accounts that cannot be dismissed as mere rhetorical embellishment. Papers with (...) illustrations often display a second argumentative structure differing from the text's. Constraints on adequate testing and confirmation analyses are adduced. "Experiments are about the assembly of persuasive arguments, ones that will stand up in court.... The task at hand is to capture the building-up of a persuasive argument about the world even in the absence of the logician's certainty." --Galison, How Experiments End, 277. (shrink)