 We sometimes think about the ethical significance of merely possible circumstances. People sometimes wonder, for example, if it would have been wrong to break certain promises that they in fact kept. Examples like this do not exhaust the significance of possibility—or modality more generally—in our ethical thinking. Rather, we also seem to be committed to a certain modal structure in our ethical commitments. To see this, consider an example. Suppose that a bank manager wrongfully embezzles their client’s money. If we imagine holding fixed how much the bank manager stole, and how; the trust their customers placed in them; what they did with the money; all of the short- and long-term consequences of their actions; and so on, it seems that there could not be a second action that perfectly resembled this embezzlement, except that the second action was right rather than wrong. Cases like this one seem to show a necessary connection: they suggest that the ethical character of the bank manager’s act cannot vary without some other facts varying as well.