It stands to reason that constitutional law is a convenient field of law for philosophical enquiry given the themes common to it and political, legal and moral philosophy. Many elements of constitutional law, be they regarding the state's structure or rights, are useful material to be examined philosophically. There is, however, a discreteness in the study of legal philosophy and constitutional theory in the Anglo-American tradition, in contrast especially with the German and French traditions of Allgemeine Staatslehre and Théorie générale de l’État. This edited volume is a powerful attempt to build a foundation to engage in such wider enquiry in the Anglo-American sphere. The book's stated ambition, however, is humbler than its name, as it aims to explore constitutional law's connections to political, legal and moral philosophy, and to comparative law and the history of ideas, in order to “open up new and fruitful lines of inquiry” (p. 6).
The 15 chapters of the book are aptly divided into four parts, under the headings of “What Is a Constitution?”, “Constitutional Authority”, “Constitutional Fundamentals” and “Constitutional Rights and Their Limitation”, but the first two chapters engage in more general discussion of legal philosophy's place in the enquiry of constitutional theory. In ch. 1, David Dyzenhaus argues that the apparently long disconnected enquiries of legal philosophy and constitutional theory can be seen, by looking at the fundamental question of what it is that “all legal orders share in having a constitution”, as already conjoined (p. 9). He issues a call to engage in Staatsrechtslehre, the German public law tradition, as the joinder of legal philosophy and constitutional theory ultimately regards the “legitimacy of the legal state” (p. 11). Dyzenhaus holds that the idea of a “thin legal constitution” is implicit in the conceptions of both legal positivists and political constitutionalists, as their conceptions contain authorisation rules that determine validity (pp. 14–16). He says that political constitutionalists argue for a “particular kind of legal constitution” (p. 21). Following Walters's distinction (ch. 2), he then urges a departure from the “linear theories of law”, to do away with “the logical problem of infinite regress” in identifying the source of normative value, which has been for him unproductively tackled by Hart and Kelsen (pp. 23, 27).
In ch. 2, Mark Walters puts forward such a distinction of linear from circular theories of law, through his account of unwritten constitutionalism. Whereas linear theories of law assume that law's starting point is external to law, circular theories maintain that the normative order is held together like “a web of strings” rather than just one string whose normative force is traceable back to the original source of law. Drawing on the historical common-law concept of lex non scripta, which he refers to as “the interpretive attitude” informed by moral philosophy and the ideal of coherence (pp. 34–35), Walters invites us to take the unwritten constitution into account to make sense of “the entire constitution”. Unwritten constitutionalism, by delivering a holistic constitution, serves to fulfil the constitutionalist ideals of the pervasiveness and the ordinariness of law, respectively, meaning that governing is never arbitrary and constitutional law too enjoys the quality of being law (p. 49). For Walters, this endeavour falls within what he terms the circular theories of law, as it focuses on achieving normative unity in law rather than aspiring to locate a basic norm or establish rules of recognition. These first two chapters, by invoking legal positivism in constitutional theory and a classification in legal philosophy as to the identification of normative value, set the foundations of the book through which a constitutional philosophical debate takes place.
The subject of constitutional interpretation is unavoidably a major theme in the book. In ch. 3, Aharon Barak focuses on the “implied meaning” of written texts of constitutions. He argues that, besides the express meaning, the implied meaning is also inferred from the constitutional text and, thus, constitutional implication is not external to the text. This inference, for Barak, needs to be made with reference to the “constitutional structure”, which consists of the underlying principles that make up the constitutional scheme (p. 59). Barak instances cases where constitutional values, constitutional rights, limitation clauses, judicial review authority and eternity clauses have been inferred from constitutional texts by way of implication (pp. 62–65). He further shows that constitutional implication is applicable through intentionalism, originalism and purposivism (pp. 66–68). Barak's account of constitutional implications, in contrast to Walters's unwritten constitutionalism, does not entail a prescriptive constitutional theory, as it merely seeks to establish that, in every written constitution, there are constitutional implications that are of equal normative value to the norms derived from the express meaning of the text.
For Jack M. Balkin, in ch. 12, constitutional interpretation is central in the (re)construction of the constitution, as he regards constitutions as frameworks and contends that a constitution is always unfinished (pp. 243–44). Unlike Barak, constitutional interpretation is for Balkin not so much a discovery of meaning, but construction. He thinks that a constitution's function is to “set[] politics in motion” (p. 244), and that constitutions are constructed over time through interpretation exercised by “pretty much everyone in the political community” (p. 263) where there are social, cultural, institutional and political constraints on the judge's role (pp. 247–48) and where judicial construction is mostly a response to constructions by other actors (pp. 253–56). Sanford Levinson, by contrast, is critical of the insistence on constitutional interpretation and instead invites legal philosophers and (American) constitutional theorists to engage in the study of constitutional design, in ch. 4. He argues that interpretation is futile in the settled constitutional arrangements regarding institutional structures, and that the point is not to ponder their meaning, but to question their wisdom with their modification or excision on the table (p. 90).
The so-called Arab Spring, as yet still understudied in constitutional theory, is the starting point of Richard Stacey's chapter (ch. 8), which looks at the concept of popular sovereignty in revolutionary constitution-making. Stacey recounts the constitutional turbulence in the Arab region since 2011, with a particular focus on the “constitutional moments” in Egypt and Tunisia, as instances of peoples acting to change the constitutional order (pp. 161–62). He holds that the rule of law, specifically its manifestation in Fuller's “congruence” principle of legality, must be upheld if popular sovereignty is to exist (pp. 170–72). Stacey argues that, in constitutional interregnums, congruence is not with “previously declared rules”, but with “the principles that are inherent in the idea of popular sovereignty itself” (p. 172). For Stacey, civil and political rights, and substantive non-discrimination, make up other dimensions of the substantive constraints on the constitution-making authority that rests upon popular sovereignty (pp. 173–78).
In ch. 7, Hans Lindahl engages in a similar enquiry, though looking specifically at the place and coming about of the “we” in acts of constituent power. Through the example of the foundation of the EEC, he argues that the foundation of a legal order is successful only if it appears as the legal “re-foundation” of an already extant collective (p. 150). Lindahl's account seems to fall into Walters's group of circular theories, but a difference is that, for Lindahl, although spatio-temporally unidentifiable, a closure (or beginning) of the constitutional order “must already have transpired” (p. 150). The constitution is not so much a becoming as is the case with Walters's and Balkin's accounts. Lindahl, emphasising the prematurity of the “initiative to say ‘we’ on behalf of a legal ‘we’”, and the need to justify that initiative, further argues that the normative implications of his account endorse an inclusive “we” and the institutions which deliver that (p. 154). Although Stacey reaches a similar conclusion, he does so by limiting his account to authorities claiming to rest upon popular sovereignty and by distinguishing popular sovereignty from majoritarianism. Lindahl's theory emphasises the characteristics of the “first-person plural perspective” that views the “we” as “we together” and not “we each” and, importantly, is not limited to state constitutions (pp. 144–45). Where Malcolm Thorburn explores the practice of proportionality justification in ch. 15, he too argues that the constituent power is not boundless when seen in light of the German Rechtsstaat tradition. That tradition holds that a public authority is required, and that all its actions must be tested by courts in order to secure the “status of each person as free and independent”, as public authority owes its existence to guaranteeing this. Thorburn argues that this “status” thus precedes any popular sovereignty (pp. 315–16).
Unsurprisingly, a recurrent theme in the book is the separation of powers. In ch.11, Aileen Kavanagh, rejecting “the pure view” that sees the branches of government as having mutually exclusive functions, presents her “reconstructed view” that calls for a division of labour supplemented by checks and balances, which ideally results in institutional collaboration of the branches in the “joint enterprise of governing”. In ch. 10, where Trevor Allan argues that the rule of law entails a specific substantive conception of law (“law in its primary sense”) that secures individuals a domain of liberty (p. 217), he regards the separation of powers as “an implicit feature of the rule of law” upon which the citizen's freedom as independence depends (p. 211). Likewise, Dyzenhaus (p. 12) and Walters (p. 37) see the separation of powers as a minimum condition of constitutionality, and Levinson's call for looking at constitutional design is partly addressed to this structural aspect of constitutional law.
Lastly, Rosalind Dixon and Adrienne Stone argue in ch. 5 that constitutional amendment procedures increase the democratic legitimacy of judicial review of legislation, as they provide a mechanism of “democratic override”. They challenge the political constitutionalist criticism of judicial review by showing that in Colombia and India, unlike in the US, constitutional amendment is not always extremely difficult and can be a workable procedure. They also note that there are judicially enforced limits to amendments in both countries, but established in a way that does not render this override mechanism useless (p. 106). This part of their argument, however, may be vulnerable to the objection that this leaves no constitutional democratic override available and the only way for an override is extra-constitutional.
The book, overall, manages to give the reader a taste of what the philosophical study of constitutional law is like, and is a successful introduction to the central questions. It provides intellectual roadmaps as well as explicit encouragement along the way to scholars who might wish to engage in this field of enquiry. It incorporates useful methodological discussions of philosophical, legal and comparative study. It is worth mentioning, however, that all authors but Lindahl are based in common-law jurisdictions. Although theoretical help is laudably drawn (especially by Dyzenhaus, Walters, Lindahl, Stacey and Thorburn) from continental European public law doctrine, and although there is some powerful but eventually limited engagement with Staatsrechtslehre – but virtually none with, say, the French and Italian institutionalist literature on constitutional philosophy – the book's themes remain of a highly Anglo-American character. In any case, the book's call to comparative theoretical inquiry – as seen especially in Dyzenhaus's invocation and Walters's use of Staatsrechtslehre, Thorburn's appeal to Rechtsstaat, Dixon and Stone's urge to look away from the US context and Levinson's conceding disclaimers regarding the American nature of parts of his argument – is valuable and will help strengthen comparative legal scholarship's promise. Otherwise, that scholarship risks falling victim to superficiality and the misreading of conceptual contexts. The book, thus, does more than manage to put the philosophy of constitutional law to the place “at the crossroads of engaged normative inquiry” (p. 6).
