Abstract
Two options are incommensurable if it is neither true that one of them is better than the other, nor true that they are of equal value. A test of incommensurability between two options, which yields a sufficient but not necessary condition of incommensurability, is that there is, or could be, another option that is better than one but is not better than the other. Two incommensurable options may be of roughly equal value, but do not have to be. The existence of significant incommensurability is attested to in our refusal to compare the value of options, and this refusal to compare the value of options helps, in turn, to determine the nature of those values. Incommensurability also helps to illuminate the nature of moral dilemmas.