Incommensurability and hardness

There is growing support for the view that there can be cases of incommensurability, understood as cases in which two alternatives, X and Y, are such that X is not better than Y, Y is not better than X, and X and Y are not equally good. This paper assumes that alternatives can be incommensurable and explores the prominent idea that, insofar as choice situations that agents face qua rational agents involve options that are not rankable as one better than the other or as equally good, the choice situations are, due to this structural feature, distinctively hard. It might seem like choosing between incommensurable alternatives is obviously distinctively hard because, unlike in other cases , in cases of incommensurability, one cannot proceed in a way that does justice to the value of each of the goods at stake by factoring their value into one’s decision. The reasoning in this paper suggests that this position is mistaken, not because there is no real challenge here, but because, insofar as a challenge has been identified, it is one that can make cases involving commensurable alternatives hard too. The paper’s reasoning also suggests that the challenge at issue can sometimes, even if not always, be overcome via effective choice over time. Although many of the illustrations focused on in the paper involve low-stakes intrapersonal cases of decisionmaking, the paper’s reasoning is, as is apparent by the end of the paper, relevant for high-stakes and population-level decision-making as well.