 Frege proposed that that the solution to this puzzle involved the introduction of senses—abstract objects that fix the referents of these expressions, each having a different cognitive significance. In the case of (6), the Fregean solution would be to say that there are different senses attached to ‘the Morning Star’ and ‘the Evening Star’. If we take these expressions to be standing proxy for definite descriptions, then (6) can be unpacked as in (6′).