In 1994, Donaldson and Dunfee proposed the Integrative Social Contracts Theory (ISCT), with the aim of solving conflicts of norms often seen in the business context. But many business ethicists have pointed out that the ISCT is not easily applicable, because the concept of hypernorms is not clear. With such a point in mind, this article tries to reevaluate one of the very important contributions they made. That is an attempt to introduce the rules of thumb for prioritization. For this purpose, first I overview the theoretical framework of the ISCT. Second, I highlight their way to prioritize relevant norms, even if those norms are complicated or mutually exclusive. They call this way "the six sample rules of thumb." Since they have not developed the rules further, there remain some issues. Therefore at the end of this article, I explore a direction, so as to solve the issues.