On this view the idea of justifiability to others is taken to be basic in two ways. First, it is by thinking about what could be justified to others on grounds that they could not reasonably reject that we determine the shape of more specific moral notions such as murder or betrayal. Second, the idea that we have reason to avoid actions that could not be justified in this way accounts for the distinctive normative force of moral wrongness.
Sayfa 5 - The Belknap Press of Harvard University Press, Third printing, 2000