Abstract

C onsider two contrary conditionals 1 about two envelopes, Ali and Baba: (a) If Ali has more money than Baba, the difference between the amounts in them is $5. (b) If Ali has more money than Baba, the difference between the amounts in them is $10. Can these both be true? The answer is a resounding yes on the standard account of conditionals, which identifies indicative con- ditionals with material conditionals. It is not the same with many other contemporary accounts of c onditionals. They yield a quali- fied negative answer: (a) and (b) are not compatible 2 unless their common antecedent cannot be true. I think this is a wrong answer. The conditionals can both be true while their antecedent states a possibility. This is what I aim to show in this paper. In doing so, I present a solution to Raymond Smullyan’s intriguing version of the two-envelope paradox.