The All-Affected Principle is of limited help in thinking about immigration. Immigration raises important normative questions about who should have access to citizenship, what is required for the full social and economic inclusion of immigrants, what legal rights immigrants admitted by a state should have, how migrants who enter and settle without permission should be treated, what criteria should be used in selecting and excluding immigrants, what states ought to do in dealing with refugees, and whether controlling immigration is really morally justifiable at all. The All-Affected Principle is directly relevant only to the first question of who should have access to citizenship, and even in that case, it needs to be supplemented. The other questions are not primarily about who should participate in democratic decision-making but about what justice requires and about the moral constraints on democratic discretion. So, using the All-Affected Principle to think about those questions would not help, and starting from that principle in thinking about immigration might lead us to miss the key normative issues.

While the idea of the scientific method has wide currency, in this chapter we point to the difficulties inherent in deciding exactly what that method is. We note some of the key features of the scientific method while also identifying some of the key choices we have made in writing this book.

Constitutional law is a problem-solving activity. All problems in constitutional law, without exception, can be analyzed in terms of one or more questions, and all constitutional law questions, without exception, fall into one of two distinct categories: Does the Constitution authorize this governmental action? and does the Constitution prohibit this governmental action? This twofold logic of inquiry into authorization and prohibition guides the constitutional lawyer’s analysis of the problem in a constitutional controversy and provides the intellectual skeleton for constitutional law argument and decision. This chapter will first discuss how the logic of inquiry is used, and then will explain how the two questions are the product of the way the written Constitution is worded and of certain background presuppositions about its purposes.

The sixteen words on religion in the First Amendment have generated voluminous and vociferous scholarly interpretations. These controversies strike at the heart of the role of religion in American public life. How are we to decide which interpretation of the First Amendment is correct? Answers to this question have been laden with presuppositions. This chapter is an interdisciplinary analysis of recent historical, political, legal, and philosophical writing on the First Amendment to illustrate how key presuppositions inform the approach to arguments about the meaning, scope, and intent of the First Amendment. The chapter will first outline the contextual and philosophical problems of interpreting the First Amendment. It will then evaluate the providentialist, secular, and pragmatic presuppositions that have guided scholarly interpretations. Ultimately, the chapter will argue that there has not been a single understanding of the relationship between church and state in America, but that investigating these presuppositions can help us better appreciate the dynamic nature of religion, politics, and jurisprudence in America.