The United States today has a mature legal system. It's been in operation for over 200 years, we've got a foundational text that is widely recognized, and we've got institutions that have been implementing that in detailed ways that have built out the legal edifice over 200 years. And in that kind of legal system, there's actually not a lot of space left. There is space left, but not a lot of space left, or at least not as much as when the system was initially started for pure ethical norms to do work within that system. So it wouldn't be surprising today if direct appeals to natural law norms are relatively rare in our legal system, although they could have been more common, and in fact, they were more common at the beginning of our legal system. When you look at cases, for example, Fletcher versus Peck, you see Chief Justice Marshall referencing not just the Constitution's text and original meaning, but also his perception of what ethics required in that case as an additional reason for the interpretation that he was offering for the contracts clause. And so you saw more of that early on, but then once you have the precedents in place, you no longer need to, or at least there's not as much of a need to appeal directly to ethical norms as there was when you didn't have precedents in place. In fact, that's evidence that the lack of appeals to natural law norms is evidence of the proposition I was arguing for, which is that the positive law is this implementing mechanism of the Constitution and of the natural law commitments to pursuing the common good. And so, one should not directly appeal to the natural law when you have the positive law doing that system relatively well. What role does the natural law play in a mature legal system like our own? So when I think of the US Constitution, I think what the natural law tradition does is it allows us to better understand, to better explain, and to bring to the fore things that might otherwise be hidden from us. Let me give you some examples. So when you look at the Preamble, the Preamble for the most part plays no role in American constitutional law. But when you look at the Preamble, the Preamble is evidence of what were the purposes of the framers and ratifiers in drafting and adopting, and then implementing the Constitution? And when you look at what the Preamble is saying, it's not saying only that we're trying to protect natural rights, or the Preamble's not saying only that we want to facilitate the democratic processes of the American people. It's saying those things, but in addition to that, it's talking about other capacities, other components of what, in the natural law tradition, we call the common good. So for example, justice. So justice is a substantive commitment about how humans as individuals should treat each other, and how humans within a community should be treated by the community and other members of that community, and the preamble references that directly. And so I think when you look at the text of the Preamble in the natural law tradition, it brings to light that the purpose of James Madison and the other framers and ratifiers was they saw that the Articles of Confederation was not adequately securing or pursuing the common good, and that this new project, this new Constitution was meant to secure the common good.