II is an assumption of the author because the inconsistency of which the author accusses others would disapear if, though they were not poor, they nonetheless endured great suffering, e.g., emotional pain or poor health. I is not an assumption of the author. The author is trying to prove the existence of a contradiction in another's words and actions: It is the others who insist suffering is necessary. The author never says one way or the other whether suffering is necessary to produce art - only that these others claim it is, and then eat well. Finally, III incorrectly construes the author's reference to purchasers of art. There is no mention of the role of the critic.