In the wake of the news of the concentration camps, Foot was haunted by the notion that there was no way to rationally overcome a moral standoff with a Nazi. She wanted to argue that moral evaluation (“It is wrong to kill innocent people”) is not fundamentally different from factual evaluation (“It is incorrect that the earth is flat”). A cynic should no more be able to deny the moral implications of a relevant body of evidence than a flat-earther can deny the factual implications of astronomical data. It was Anscombe, a devoted Catholic, who liberated Foot, a lifelong atheist, to dare to think in this outmoded fashion. Foot had been speaking of the conventional contrast of “ought” and “is,” and Anscombe feigned confusion. “She said: ‘Of what? What?’ ” Foot recalled. “And I thought, My God, so one doesn’t have to accept that distinction! One can say, ‘What?’!”
Would that more philosophers would at least ask "What?" when talking of the ought/is distinction.