This talk will center around two phenomena. First: Why is it that a statement like "The distance between Tokyo and Kyoto is four hundred kilometers" gets interpreted in a more vague way than a statement like "The distance between Tokyo and Kyoto is three hundred eighty seven kilometers"? Second: Why is it that a statement like "Mary is not unhappy" typically expresses a greater state of happiness than a statement like "Mary is not happy"? I will show that these questions find a principled answer in Bidirectional Optimality Theory, a theory of interactions of pragmatic principles that allows to compare competing forms and competing meanings.