 As we saw in section 7.3, an important objection to the idea of public reason is that it will prove incomplete; that it lacks the theoretical resources necessary to provide answers to many of the important moral or political questions we face. Although this objection is often voiced by critics of public reason, the existing literature provides relatively little in the way of detailed case-by-case analysis of the plausibility of the charge (exceptions include J. Williams 2015; J. Williams 2017, Other Internet Resources; Greenawalt 1988). In particular, the charge of incompleteness seems most plausible when we consider certain “problems of extension”, that is, topics where it is unclear whether public reason can be extended to provide reasonable answers (Rawls 1996, 244–246). Some examples of these problems include: What principles should regulate our treatment of future generations? What principles should regulate our treatment of animals and nature? What principles should apply to decisions about the provision of health care? For each of these questions, there is a plausible prima facie case that our deliberations must be informed by considerations that go beyond the limits of public reason and appeal to controversial claims about the moral status of animals, or future persons, or particular claims about what constitutes human flourishing. But whether this is indeed the case with regard to these issues, among others, is something that awaits more sustained analysis.