On the focus-sensitivity of counterfactuality

Abstract

I show that the presence of the additive particle ‘also’ can have the effect of cancelling the counter factuality of the consequent in counterfactual conditionals, but only when ‘also’ focus-associates with material inside the antecedent. Adopting Karttunen’s (1971) idea that conditional perfection (CP; the strengthening of conditionals to biconditionals) is a necessary ingredient of the counterfactual inference of the consequent (which I write ‘CFq’), it follows that when CP is blocked, CFq is also blocked. I show that when ‘also’ associates with material in the antecedent of the conditional, it reflects a context in which multiple causes for the same consequent are salient (a multiple-cause context). I then argue that multiple-cause contexts block CP. This gives rise to a more general characterization of the set of contexts that block CFq: both other realizations of multiple-cause contexts (that do not contain ‘also’), and contexts that block CP for other reasons are included in this set.