Applying Citizenship Theory to Brexit
The Functionalist Theory
Citizenship, conceptually speaking, is a so-called middle-term.8 This is the starting point of the functionalist theory of citizenship, which is a general theory of citizenship that provides a framework for de lege ferenda analysis of citizenship laws. A general theory of citizenship, to be such, needs to describe the relationship between entitlements and access criteria. Entitlements are about what citizenship consists in. Access criteria determine to whom the status is conferred. These two dimensions constitute the concept’s extension and intension, in the philosophical sense.
Extension is determined by answering the query ‘Who is the citizen?’ To answer such a query is to give a list of criteria for acquisition and loss of the status. These criteria give us information about which persons are denoted by the term. Intension is determined by the query ‘What is a citizen?’ To answer such a query is to indicate a set of entitlements or legal positions - typically rights and duties. To determine intension is therefore to indicate the content of citizenship. Intension, in other words, defines the properties connoted by citizenship.
Both intension and extension vary. This has led many to conclude that we cannot know beforehand anything about the variation. This is wrong. The two dimensions do not vary indefinitely. Their variation is intelligible and can be studied. The illusion of indefinite and rationally uncontrollable variation arises when one studies one dimension of citizenship separately from the other.
Emboldened by this insight, the functionalist theory develops two ideas: The constitutional-sensitivity thesis and the correlation thesis.
The constitutional-sensitivity thesis submits that information on citizenship, in its combined form, consisting both of access criteria and entitlements, is a source of constitutional meta-data: The variation of extension (i.e. criteria for acquisition and loss) in relation to intension (i.e. legal positions associated with the status) provides information about the constitutional identity of a polity. This is so because nationality law is not just any area of law. The power to define the demos, to determine who counts as citizens - the flip side of the state’s ‘power to exclude’9 - is essential to the existence and identity of the state. There is a correlation between the role of the citizenry and nature of the polity (Mindus 2016). To define this role attention needs to be paid to both entitlements connected to the status and criteria for acquisition and loss. Access to citizenship regulates how the demos (or set of citizens) is composed; and entitlements determine their share of power. The composition and role of the demos in a legal order is determinative of its constitutional identity. Ever since Aristotle, the number of people allowed to hold office and share political power constitutes a measure defining the form of government.10 This is the fundamental intuition behind the constitutional-sensitivity thesis.
According to the correlation thesis, access to status civitatis is not neutral, but can be conceived as a variable of the content of the status. There is a relationship between the two dimensions that is best described as a functional correlation, in the mathematical meaning of function. This correlation is functional in the sense that criteria giving access to the status and the type of entitlements it entails have to be aligned so that access criteria fit the particular type of entitlements connected to the status. If they are not aligned by functional correlation, citizenship becomes an arbitrary instrument of social closure: As if we were to distinguish insiders from outsiders randomly. Who is eligible for citizenship is a question that depends on the features required to enjoy the entitlements and perform the duties of citizenship. Which characteristics, capabilities, distinctive features are relevant, and reasonable to require, depends on the type of rights and obligations that a given ‘citizenship’ consists in. Therefore access to the status is functionally correlated to the content of it. Changing one impacts the other. The functional correlation can be expressed as follows:
I use the term codomain (C) to refer to extension (i.e. criteria for acquisition and loss of citizenship) and domain (D) to refer to intension (entitlements or legal positions associated with the status). Both are nonempty sets.11 The domain is the set of the arguments for which the function is defined; the codomain is the target set. No submission is made about cardinality at this stage.
The correlation thesis claims that criteria for acquisition and loss of the status constitute a function of the entitlements it consists in. Symbolically, it can be summarised in the following way:
In other words, f is a surjective function from D to C so that:
The function is surjective because every point in the codomain is the value off(d) for at least one point d in the domain.
We can operate in two ways to better understand a particular case of status civitatis: Given a set of criteria of acquisition and loss, the intension that can be connected to such an extension may be inferred. Otherwise said, if we have knowledge about criteria for acquisition and loss, we may infer compatible entitlements. Given a set of entitlements, we may deduce what extension fits this intension. In other words, if we know what a given citizenship consists in (i.e. the rights and duties that are connected to the status) we are in a position to tell, consistently with the content of the status, which criteria for acquisition and loss are consistent with the entitlements.
If the characterisation of the relationship between intension (D) and extension (C) in terms of functional correlation is correct, we obtain a standard for evaluating the appropriateness of criteria for acquisition and loss. We can thus analyse the internal consistency of the design of a given citizenship policy. The functionalist theory offers a standard against which we can test whether granting citizenship is justified; or, if you prefer, a standard allowing for principled reasoning about the design of citizenship laws.
If the design is to be consistent, extension will follow intension in such a way that to who citizenship is granted must depend on what citizenship consists in. Here are three examples taken from well-known approaches to citizenship. First example: If we assume that the intension is given by, for example, political autonomy, it is consistent that extension is determined by, for example, adulthood (proxy for maturity). Therefore, age is a reasonable criterion for access to franchise. Second example: If the intension is given by, for example, subjecthood to the legal order, then it is consistent that extension is determined by, for example, birth on the territory (proxy for physical presence). Therefore, ius soli is a reasonable for criterion for acquisition of citizenship. Third example: If the intension is given by, for example, ensuring transgenerational solidarity, then it is consistent that extension is determined by, for example, descent or family ties. Therefore, ius sanguinis is a reasonable criterion for acquisition of citizenship.
It is important to notice that the standard is not reliant on factors that vary with the observer, for example, political opinion, worldview, conceptions of the good and more. It relies on internal consistency between input data (i.e. which legal positions - rights and duties - a given citizenship consists of) and output data (i.e. criteria for acquisition and loss).