A note on Lewis on counterfactual dependence in a chancy world
1. In a Postscript,1 David Lewis tries to extend results obtained in his (1979) from the deterministic case to the indeterministic one. In particular, he claims that under the supposition that the actual world is indeterministic, the truth of the counterfactual 'If Nixon had pressed the button, there would have been a nuclear holocaust' is reconciled with his truth conditions for counterfactual conditionals by a certain refinement of his earlier treatment. Sections 2 to 5 explain why his claim is mistaken. Section 6 remarks why this matters.