 In contrast, Buchanan, et al., favor putting the person-based approach together with a substitutional form of pluralism. On their view, many of our obligations are person-based in nature, including the obligation to avoid making a particular person worse off or causing that person to suffer a “serious loss of happiness or good” when the agent can do so without imposing “substantial burdens” on others. This is their “Principle M” (Buchanan, et al. 2000, 226). In some cases, however, we have obligations that go beyond Principle M. It is here that their impersonal “Principle N” is triggered, prohibiting agents from letting their dependents – including their children – “experience serious suffering or limited opportunity or serious loss of happiness or good” if “they can act … without affecting the number of persons who will exist and without imposing substantial burdens … on themselves or others …” (Buchanan, et al. 2000, 249).