  There is a problem in understanding quite what a ‘synthesizing category’ or ‘covering value’ is. How does the covering value determine the relative weightings of the constituent values? One possibility is that it does it by pure  stipulation—as a martini just is a certain proportion of gin and vermouth. However, stipulation does not have the right sort of explanatory power. On the other hand, if a view is to remain pluralist, it must avoid conflating the super scale with a super value. Chang argues that her covering values are sufficiently unitary to provide a basis for comparison, and yet preserve the separateness of the other values. Chang’s argument goes as follows: the values at stake in a situation (for example, prudence and morality) cannot on their own determine how heavily they weigh in a particular choice situation—the values weigh differently depending on the circumstances of the choice. However, the values plus the circumstances cannot determine relevant weightings  either—because (I am simplifying here) the internal circumstances of the choice will affect the weighting of the values differently depending on the external circumstances. To use Chang’s own example, when the values at stake are prudence and morality (specifically, the duty to help an innocent victim), and the circumstances include the fact that the victim is far away, the effect this circumstance will have on the weighting of the values depends on external circumstances, which fix what matters in the choice. So, as Chang puts it, “‘What matters’ must therefore have content beyond the values and the circumstances of the choice” (2004, p. 134).