Abstract

You've just read the first sentence of this paper. Would you have read it if some butterfly in Brazil had had some extra nectar for breakfast? You probably think so. But this trivial observation apparently has very dramatic consequences. For instance, it seems to imply that you would have read that very sentence even if someone had offered you $1.000.000 not to do so. This paper is about what thus looks like a paradox in that a counterintuitive conclusion can seemingly be derived from plausible premises and assumptions. The key is to recognise that ‘you would have read the sentence if the butterfly had feasted’ admits of distinct readings: one on which it is false, which is the traditional counterfactual implying causal relevance, and another on which it is true, which we call an irrelevant semifactual. While a fully satisfactory solution would need to develop and defend a semantic analysis of such conditional sentences, our modest aim is merely to sketch how the paradox might be solved. The underpinning theoretical work is for a different paper.