> If it was uniquely specified then we could just use probability theory with its axioms and inference rules to derive at the correct answer. You’re right. I

> If it was uniquely specified then we could just use probability theory with its axioms and inference rules to derive at the correct answer. You’re right. I wrote in another comment the solution down to this two unspecified elements: P(you tell me that you have two children including at least one boy | you have two boys) P(you tell me that you have two children including at least one boy | you have one boy and one girl) If one assumes that they are equal (why?) the answer is 1/3. If one assumes that the latter is half as probable the answer is 1/2. Whatever the assumption that one finds more natural the point is that an assumption is needed.