Counterfactuals, irrelevant semifactuals and the $1.000.000 bet

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—and most other sensible people—probably think so. True, small deviations from the actual course of events may bring about more widespread and dramatic changes.
Many things could be affected by such an extra nectar intake. But not everything. Many other things would remain unaffected, including the fact that you just read the first sentence of this paper.However, this trivial observation apparently has very dramatic consequences. For instance, it seems to imply that you would have read that very sentence no matter what—even if, say, 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 plan is as follows. In (§1)
it is explained why you would have read the sentence even if our butterfly had had an extra breakfast, and then in (§2) why it follows that you would have read it no matter what. The key is in (§3) to recognise that our counterfactual, and others like it, admit of distinct readings: one on which it is false, and another on which it is true, that you would have read the sentence if the butterfly had feasted. 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.