Abstract

Both Kratzer 1981 (“Partition and Revision”) and Kratzer 1989 (“Lumps of Thought”) assume that the truth of counterfactuals depends on a parameter. The parameter provides a set of propositions that uniquely characterizes the actual world in Kratzer 1981, and a so-called “set of propositions relevant for the truth of counterfactuals” in Kratzer 1989. Both papers try to find empirical constraints for the relevant sets, but - crucially - without characterizing them uniquely. The vagueness and context-dependency of counterfactuals is assumed to be in part due to the fact that the set of propositions that the truth of counterfactuals depends on is underdetermined.