A story that illustrates all four throughlines (Overall Story, Relationship Story, Main Character, and Impact Character) and their every story point so that no holes are left in either the passionate or dispassionate arguments of that story
A Grand Argument Story covers all the bases so that it cannot be disproved. From the perspective that it creates, it is right. There are four views in a complete story which look at all the possible ways the story could be resolved from all the possible perspectives allowed; these are represented by the perspectives created by matching the four Throughlines with the four Classes (the Overall Story, Relationship Story, Main Character, and Impact Character Throughlines matched up with the Classes of Situation (Universe), Activities (Physics), Manipulation (Psychology), and Fixed Attitudes (Mind) to create the four perspectives of the particular story they are operating in). Every complete storyform explores each of these perspectives entirely so that their views of the story's problem are consistent and that they arrive at the only solution that could possibly work, allowing the givens built into the story from the start. When this is done, a Grand Argument has been made and there is no disproving it on its own terms. You may disagree with they story's givens, but as an argument it has no holes.