Frank Ramsey writes: If two people are arguing ‘if p will q?’ and both are in doubt as to p, they are adding p hypothetically to their stock of knowledge and arguing on that basis about q. We can say that they are fixing their degrees of belief in q given p. (1931) Chalmers and Hájek write: Let us take the first sentence [of Ramsey] the way it is often taken, as proposing the following test for the acceptability of an (...) indicative conditional: ‘if p then q’ is acceptable to a subject S iff, were S to accept p and consider q, S would accept q. (shrink)