  Duhem does not claim that when there is some conflict with experience, we can always make enough adjustments elsewhere in the system. He makes a weaker claim, also limited in other ways, but which would be equivalent to: when there is some conflict with experience what is disconfirmed is necessarily ambiguous. Duhem’s formulation of his non-falsifiability thesis is that “if the predicted phenomenon is not produced, not only is the questioned proposition put into doubt, but also the whole theoretical scaffolding used by the physicist” (1914, 281; 1954, 185). He does not take the second Quinean step of holding any statement true come what may, but says “the only thing the experiment teaches us is that, among all the propositions used to predict the phenomenon and to verify that it has not been produced, there is at least one error; but where the error lies is just what the experiment does not tell us” (1914, 281; 1954, 185). He refers to two possible ways of proceeding when an experiment contradicts the consequences of a theory: a timid scientist might wish to safeguard certain fundamental hypotheses and attempt to complicate matters by invoking various cases of error and multiplying the corrections, while a bolder scientist can resolve to change some of the essential suppositions supporting the entire system (1914, 329; 1954, 216–17). The scientist has no guarantee of success: “If they both succeed in satisfying the requirements of the experiment, each is logically permitted to declare himself content with the work he has accomplished” (1914, 330; 1954, 217).