Recent years have witnessed renewed attention to constitutions by both academics and policy makers. This is hardly surprising given that constitutions are the foundation for government in virtually every society around the world. They simultaneously create, empower, and limit the institutions that govern society. In doing so, they are intimately linked to the provision of public goods. Outcomes, like democracy, economic performance and human rights protection, are all associated with the contents of countries' constitutions. It is little wonder, then, that constitutions are often blamed for poor economic and political outcomes or that such outcomes commonly result in constitutional change.
Despite the centrality of constitutions in both scholarship and practice, there is some confusion about the precise definition of a constitution. For instance, the late Walter Murphy, one of the most distinguished scholars of constitutional law, was fond of interrupting conversations about "constitutions" with the pointed interjection, "you mean the text, right?" Others have elaborated Murphy's point that the written text is not perfectly contiguous with the larger constitutional order of a country, an order that might include "super-statutes," decisions of judges and agencies, and even informal institutions. If one is to understand the difference between a country's written constitution and its larger constitutional order, it is important to distinguish between the functions of a constitution and its form.
Constitution-As-Function versus Constitution-As-Form
The principal divide regarding the use of the term constitution has to do with its reference to either certain functions (however achieved) or a certain form (whatever its function). The constitution in the first connotation comprises those elements (e.g., laws, theories, and interpretations) that perform what are traditionally understood as "constitutional" functions. The constitution in the second connotation refers to the formal written charter, a form that is now nearly universal among modern states.
To understand the first conceptualisation, that of constitution-as-function, we should clarify what scholars view to be the traditional purposes of constitutions. A central idea here is the limitation of government power. Constitutions generate a set of inviolable principles and more specific provisions to which future law and government activity more generally must conform. This function, commonly termed constitutionalism, is vital to the functioning of democracy. Without a commitment to higher law, the state can operate for the short-term benefit of those in power or the current majority. Those who find themselves out of power may find that they are virtually unprotected, which in turn may make them more likely to resort to extra-constitutional means of securing power. By limiting the scope of government and precommitting politicians to respect certain limits, constitutions make government possible.
A second function that constitutions serve is the symbolic one of defining the nation and its goals. In this conception, the constitution functions not so much as a set of rules as an ongoing set of practices that define the political unit, facilitating, under some circumstances, the emergence of constitutional identity.
A third and very practical function of constitutions is that they define patterns of authority and set up government institutions. This function differs from the constitutionalism function of limiting government. Although the mere process of defining an institution involves some constraints on its behavior, these organizational maps are conceptually distinct, albeit subtly, from the substantive and entrenched limits on government action incorporated into the notion of constitutionalism.
Functional definitions identify the constitution as comprising those rules or understandings that purport to accomplish the functions described above. The functional constitution includes the formal, written constitution as well as the collection of legal theories, norms, customs, and understandings that make up some intersubjective consensus about what constitutes the fundamental law of the land. The functional constitution is sometimes referred to as the constitutional order or the "small-c" constitution.
More formal definitions limit the term to encompassing only the founding charter - that is, the nominal or written constitution - regardless of whether it adequately serves the aforementioned functions. This is sometimes referred to as the "large-c" Constitution and is more in tune with what ordinary citizens in most countries think of when they hear the word constitution. A standard operational definition of written constitutions is the one developed by the principal investigators of the Comparative Constitutions Project (CCP), which involves a set of three conditions to assess a law's status as a "Constitution":
- The document is identified explicitly as the Constitution, Fundamental Law, or Basic Law of a country
- The document contains explicit provisions that establish it as the highest law, either through entrenchment or limits on future law
- The document defines the basic pattern of authority by establishing or suspending an executive or legislative branch of government.
The first condition is sufficient to qualify a document as a constitution, whereas the others are applied as supplementary tests if the first is not met. According to this operational definition, the United Kingdom is the only country in the world without a written constitution.
This description of a constitution is based on the distinction between formal constitutions and the constitutional order in Chapter 3 of The Endurance of National Constitutions