Federal Law Review
In Singh v Commonwealth ('Singh'), the High Court was presented with the question whether a person born in Australia can be considered an 'alien' for the purpose of s 51(xix) of the Constitution ('naturalization and aliens'). In a 5:2 decision the Court rejected the plaintiff's argument that birth in Australia necessarily accorded her the status of non-alien and thus a constitutional nationality which could not be displaced by legislative reliance on other heads of power. The decision is important, both for its elucidation of Parliament's scope to regulate Australian citizenship — the subject of a series of important cases over the last two decades involving strong dissents and two reversals in approach — and for its consideration of principles of constitutional interpretation.
Central to the decision in Singh was the extent to which the Commonwealth Parliament's power to pass laws with respect to a status such as 'alien' includes the power to define that status. That is, in the present context, if the constitutional status 'alien' is merely the antonym of citizen — itself a statutory concept — Parliament is essentially able to define the extent of its power. Such an outcome is of course inconsistent with established doctrines of constitutional interpretation; indeed, with the very notion that the Constitution (interpreted by the High Court) defines Parliament's power. However, delimiting the constitutional scope of legislative powers which refer to a legal category or status in an 'objective' or 'independent' manner that does not merely reflect the legislative definition or meaning attributed to such category or status is not a straightforward issue, as is evidenced in the case of other heads of power such as marriage, copyrights, patents and trade marks, and bankruptcy and insolvency.
Thus, one unresolved issue following Singh is the extent to which Parliament's power with respect to aliens, while clearly wide, is limited. Is there remaining scope for establishing a constitutional category of non-alien (who may or may not be entitled to the statutory right of citizenship)? Further, is there any scope for finding a constitutional right of nationality (which is again wider although perhaps not completely unrelated to the question of statutory citizenship)? Implicit in each of these issues is the fundamental question of the extent to which Parliament may legislate to exclude particular groups of persons from the benefit of Australian (statutory) citizenship — either by altering the rules regarding acquisition of nationality or by legislating to remove citizenship previously acquired (the converse of 'naturalization'). The decision in Singh, and in particular the touchstone for identifying an 'alien' formulated by the joint judgment (and affirmed by six judges in a subsequent decision), also leaves open its application to and ramifications for various categories of people, including stateless persons and those with dual nationality.
This case note assesses the methodology and reasoning of each of the judgments in Singh and considers the implications of the decision for Australia's citizenship laws. It begins with an overview of the background and issues in Singh and then proceeds to an analysis of the judgments before turning to a consideration of the ramifications of the decision.
Tania Singh was born in Mildura, Victoria on 5 February 1998, the daughter of two Indian citizens who had arrived in Australia in April 1997. Although Kirby J expressed some uncertainty as to whether the plaintiff was a citizen of India, the other judges proceeded on the basis that she was a citizen of India by descent. Despite her birth and continuous residence from birth in Australia, Singh was not eligible to apply for Australian citizenship pursuant to the Australian Citizenship Act 1948 (Cth) because she was unable to satisfy either of the requisite conditions, namely that one of her parents was at the time of her birth an Australian citizen or permanent resident, or that she had been ordinarily resident in Australia for a period of ten years. It is important to note that while birth in Australia had previously been sufficient to attract Australian citizenship, the Australian Citizenship Act was amended in 1986 to prevent 'migration laws [from being] circumvented through the acquisition of Australian Citizenship status by children born in Australia to temporary or illegal entrants.' As a consequence Singh was a non-citizen of Australia. Since she had no substantive visa (her parents' application for a protection visa having been rejected), she was liable to removal from Australia under s 198 of the Migration Act 1958 (Cth) as an 'unlawful non-citizen'.
The plaintiff filed a writ of summons in the High Court seeking a declaration that, inter alia, s 198 of the Migration Act was incapable of being validly applied to her. The key issue was whether s 198, in its application to the plaintiff, was validly made pursuant to the power to make laws with respect to 'naturalization and aliens' (Australian Constitution s 51(xix)). The plaintiff contended that, by virtue of her birth in Australia, she was not an alien within the meaning of s 51(xix). Kirby J subsequently stated a case for the consideration of the Full Court. The (amended) questions for consideration were (relevantly) as follows:
1. Is the plaintiff an alien within the meaning of s 51(xix) of the Constitution?
2. If the answer to (1) is 'No', is s 198 of the Migration Act 1958 (Cth) capable of valid application to the plaintiff?
At the outset it is important to be clear about the relevant terminology engaged in this context. Unlike the United States Constitution, the Australian Constitution does not contain any provision conferring Australian citizenship; nor does it expressly empower the Parliament to make laws with respect to citizenship. Indeed, the only reference to the concept of 'citizen' in the Constitution appears in s 44(i), which provides that a citizen of a foreign power is incapable of standing for Parliament. Rather, phrases such as 'people of the Commonwealth' and 'subject of the Queen' are engaged, reflecting (particularly in the case of the latter phrase) the 'political realities' at federation. As a consequence, the concept of citizenship in Australian law is a purely statutory one, having been introduced in 1948. In light of this, the primary issue for the judges in Singh was not whether Singh was a 'citizen' of Australia (she was clearly not a citizen within the Australian Citizenship Act), but rather whether she held the constitutional status of non-alien, thus taking her outside the purview of the aliens power.
As the majority of the Court answered 'Yes' to question 1, it was unnecessary for the majority judgments to consider other possible heads of power (such as 'immigration and emigration' or 'external affairs') which may have authorized s 198 in its application to the plaintiff. However, having found that the legislation could not be upheld under s 51(xix), McHugh and Callinan JJ in (separate) dissenting judgments necessarily had to consider the relevance of other heads of power, which raised the broader question not only of whether Singh was a non-alien but whether she was entitled to some kind of constitutional nationality which was unable to be displaced by otherwise relevant heads of power.
The principal argument of the plaintiff was that both the Convention Debates and common law history established that, at federation, the term 'aliens' would clearly not have encompassed persons born in Australia. It was submitted that the traditional common law position that citizenship (or, more accurately, the status of 'subject of the Queen') is governed by jus soli ('right of the soil') as opposed to jus sanguinis ('right of descent') — more commonly adopted in civil law countries — was well understood by the drafters of the Australian Constitution. The common law position articulated in Calvin's Case in 1608 was based on the notion that all those owing allegiance to the Crown were British subjects and that all those born within the sovereign's territory owed allegiance to the Crown. The plaintiff argued that the Australian Constitution 'preserves the reciprocal relationship between the Queen of Australia and the people of the Commonwealth who owe her allegiance', and thus Parliament cannot legislate to remove this constitutional nationality. Indeed, the plaintiff contended that the Convention Debates reveal that a key reason for declining to confer legislative power on the Commonwealth with respect to citizenship was the concern that Parliament might use this power to remove the common law 'birthright' of those born on Australian soil.
The Commonwealth disputed the usefulness of the Convention Debates in resolving the precise issue before the Court, and also cast doubt upon the clarity of the common law position at federation. In particular, the Commonwealth pointed to 19th century legislative changes which suggested that the traditional British preference for jus soli had undergone significant amendments prior to federation. These changes in part reflected even more dramatic developments in the citizenship laws of European states throughout the 19th century, which had produced the result that while citizenship by birth (jus soli) was the general rule at the beginning of the 19th century, the rule of descent or blood (jus sanguinis) was the 'leading principle in Europe' by the turn of the 20th century.
In oral argument significance was also placed on the correct approach to constitutional interpretation. The plaintiff engaged the Convention Debates and common law history in support of a position that essentially established a fixed meaning of 'alien' in 1900, thereby restricting Parliament's powers and providing a broad scope of protection for non-statutory citizens who can be categorized as non-aliens. By contrast, the Commonwealth emphasized the contemporary circumstances (ease of air travel, globalization) which support the need for a broad view of Parliament's power to formulate appropriate citizenship laws for Australia. Whether or not this difference in interpretative approach was ultimately determinative will be considered below.
Gleeson CJ began by setting out his Honour's previously expressed view that ss 51(xix) and (xxvii) ('immigration and emigration') of the Constitution authorize the Parliament to 'create and define the concept of Australian citizenship, to prescribe the conditions on which such citizenship may be acquired or lost, and to link citizenship with the right of abode'. His Honour adopted the statement by Brennan, Deane and Dawson JJ in Lim that 'alien' in s 51(xix) has 'become synonymous with non-citizen'. However, as alluded to above, the ability of Parliament to define the scope of its legislative power must be limited. Accordingly, Gleeson CJ conceded that '[e]veryone agrees that the term 'aliens' does not mean whatever parliament wants it to mean'. That is, to adapt an oft cited statement of Gibbs CJ from Pochi v Macphee, 'Parliament cannot, simply by giving its own definition of "alien", expand the power under s 51(xix) to include persons who could not possibly answer the description of "aliens" in the Constitution'. However, having acknowledged Parliament's limits, Gleeson CJ did not attempt to define those limits or to give content to the term 'alien' by reference to a set of criteria that would provide guidance as to what could and 'could not possibly answer [that] description'.
How then did Gleeson CJ reach the conclusion that Singh was properly considered an alien? Responding to the plaintiff's arguments regarding historical materials, Gleeson CJ found that contrary to the unified and clear picture of the state of the common law depicted by the plaintiff, in 1900 'questions of nationality, allegiance and alienage were matters on which there were changing and developing policies, and which were seen as appropriate for parliamentary resolution'. That is, while jus soli had been the governing approach for centuries, the British Parliament had intervened in the latter half of the 19th century to amend this position in 'significant respects'. Given that the law was in a state of flux at the time of drafting, the legal context did 'not support or require a conclusion that "aliens"…excludes the plaintiff.'
Turning to the Convention Debates, Gleeson CJ noted that in 1898 Dr Quick had proposed that the delegates either insert a definition of citizenship in the draft Bill or confer a power on the Parliament to define citizenship. After reviewing the Debates, his Honour concluded that they were not able to throw light on the purpose or object of s 51(xix), since it is impossible to discern any specific reason for the rejection of Quick's 'ambiguous proposal concerning citizenship.' As a result, the plaintiff's argument was not made out.
The joint judgment of Gummow, Hayne and Heydon JJ ['the joint judgment'] was the only judgment of the majority to grapple with the content of 'alien' status, or in other words its 'core' or essential features or characteristics. Their Honours' reasoning can be encapsulated in the following syllogism:
An alien is a person who owes allegiance to a foreign state.
Ms Singh owes allegiance to a foreign state (by virtue of her Indian citizenship).
Ms Singh is an alien.
Their Honours derived the key criterion of owing 'allegiance to a foreign state' by reference to pre-federation history. This historical assessment revealed that, as Gleeson CJ had found, by the end of the 19th century the word 'aliens' no longer had the fixed legal meaning established in Calvin's Case in 1608. However, what did remain unaltered, according to the joint judgment, was that 'aliens' included 'those who owed allegiance to another sovereign power, or who, having no nationality, owed no allegiance to a sovereign power.' This was said to focus correctly on what characteristic or element gives a person the status of 'alien', namely, owing obligations to another sovereign power, rather than seeking to define the status descriptively by reference only to the list of persons to whom it applied in 1900. Or, to use terminology engaged in previous jurisprudence, the joint judgment sought to identify the connotation of the word 'alien' by reference to its central characteristic.
The joint judgment rather cursorily dismissed dicta from previous High Court authority, particularly the early decision of Potter v Minahan, in which the Court had stated that 'every person becomes at birth a member of the community into which he is born, and is entitled to remain in it until excluded by some competent authority'. This and other more recent dicta relied upon by McHugh J in dissent, which appear to assume that birth in Australia takes a person outside the aliens power, were said not to be binding since none of those cases concerned the precise issue before the Court in Singh.
The final majority judge, Kirby J, departed from the other majority judgments with respect to the question of constitutional interpretation in that his Honour eschewed reliance on historical materials (including both common law and the Convention Debates) as supporting the ossification of the constitutional meaning of 'aliens' as at 1901. Rather, consistent with his well established contemporary approach to the meaning of constitutional terms, Kirby J approached the key issues on the supposition that the legislative power with respect to 'aliens' is 'capable of application to a larger, contemporary, condition of things beyond what might have been the generally accepted meaning of the word at the time of Federation'. Notwithstanding this, his Honour conceded some role for consideration of the 'framers' intentions', and in this regard noted that at federation there were two primary theories — jus soli and jus sanguinis — 'vying for acceptance amongst the nations of the world in 1901'. Moreover, while jus soli had traditionally been the theory favoured by the common law, it had already admitted significant exceptions by 1900. Thus, Kirby J concluded that it was unconvincing that the federal Parliament 'was forever to be limited to the approach of birthright'. On the contrary, according to Kirby J, a status such as alienage of its nature evolves over time, and must be capable of responding to contemporary challenges such as the impact of aviation and other modes of rapid transport that 'make possible, in ways unthinkable in 1901, adventitious arrivals of parents, with confinement and birth arranged within the receiving country'.
Despite envisaging a wide scope for legislative power pursuant to 'naturalization and aliens', Kirby J was careful to reserve the ability of the Court to impose limits on Parliament's power so as to guard against future abuse of the 'aliens' power. However, like Gleeson CJ, his Honour did not attempt to delimit the power or provide content to the meaning of 'alien' by reference to defining factors or characteristics. Rather, Kirby J emphasized that 'this court can be trusted to draw the necessary constitutional line' if Parliament attempts 'to push the "aliens" power into extreme circumstances'. In this case, the operation of the law on the plaintiff could not be viewed as 'extreme'; thus the plaintiff failed. While Kirby J's judgment provides some insight into the types of cases which might be considered extreme (that is, if the Parliament were to deem a person born in Australia an alien 'despite parental or grand-parental links of descent and residence'), it gives at most a descriptive list of persons who might fall outside the term 'alien', but no conceptual basis for distinguishing aliens from non-aliens.
The most extensive and strongly worded judgment in dissent is that of McHugh J. As in the joint judgment, McHugh J's reasoning is evidenced in a (poly)syllogism: 
An alien is a person who does not owe permanent allegiance to the Queen of Australia.
A person who is born in Australia owes an obligation of permanent allegiance to the Queen of Australia.
Therefore, a person born in Australia is not an alien.
Ms Singh was born in Australia.
Therefore, Ms Singh is not an alien.
McHugh J derived the above criterion, like the joint judgment, from pre-federation sources which he relied upon to identify the connotation of 'aliens' in 1900. His Honour surveyed the history of the status of 'subjects of the Crown' and 'aliens' respectively, from their origins in medieval common law and the feudal system, through to the restatement of the law in Calvin's Case, which established the common law rule that all persons 'born within the King's dominions' acquired the status of a natural born subject. His Honour emphasized that at common law a natural born subject 'owed from birth permanent allegiance to the Crown'. His Honour acknowledged the common law exceptions which had developed over time, and the legislative changes in the late 19th century relied upon by the majority judgments, but concluded that they did not change the essential position that in 1900 persons within British dominions were either 'natural born subjects' or 'alien subjects'. Thus, the 'irresistible conclusion' was that 'in 1900, those who made the Constitution understood that at common law, a person born within the dominions of the British Crown was a "natural born British subject", who owed permanent allegiance to the British Crown and was not an alien.'
In his Honour's view, the Convention Debates support these conclusions as they reveal that the failure to confer on the Federal Parliament power to make laws with respect to citizenship was a conscious decision of the delegates designed to protect against a future Parliament depriving 'a person of his or her citizenship — a concept that was treated as identical with "subject of the Queen"'.
McHugh J was particularly critical of an approach which declined to provide a definition of 'alien'. His Honour noted that Gibbs CJ's assurance, that Parliament could not expand the aliens power so as to include persons 'who could not possibly answer the description of "aliens" in the ordinary understanding of the word', provides no assistance in determining the meaning of the constitutional term 'aliens'. As his Honour explained, '[t]o apply this statement, one has to know what is "the ordinary understanding of the word"… [t]hat is to say, one must have a definition of "aliens"'.
A significant feature of McHugh J's judgment is that it suggests that not only is a person born in Australia outside the purview of the 'aliens' power, but that such a person acquires constitutional nationality or citizenship which protects against Parliament's ability to remove or otherwise impair such citizenship by reliance on other heads of power. However, while it is clear that, according to McHugh J, Parliament could not deprive a person of this nationality, it is not evident what other rights, protections or liabilities might flow from recognition of this status. In other words, what would be the content of the concept of constitutional nationality?
The other judge in dissent, Callinan J, focused at length on the correct approach to constitutional interpretation. Taking the converse approach to Kirby J, Callinan J expounded a theory of constitutional interpretation which almost entirely restricts the exercise to one of construing 'the intentions of [its] makers objectively ascertained'. Accordingly, his Honour proceeded to consider the common law history and Convention Debates, and concluded that the common law position persisting at federation was that children of foreign parents, born 'within the dominions of the Crown' were British subjects, and that this was 'the contemporary legal position with which the founders were familiar'. Thus, the term alien did not at federation encompass children born on Australian soil; nor had the meaning of the word altered since that time.
Importantly, Callinan J did not merely conclude that the plaintiff was not an alien in the constitutional sense, but went further in holding that, as a person born in Australia, she was entitled 'as of right to be regarded as a national of [Australia], and in substance as a citizen, albeit not as a citizen for the purposes of the Citizenship Act'. Thus, like McHugh J, Callinan J held that there is a status of constitutional citizen or national of Australia. Further, his Honour concluded that there seems to be 'no reason why the plaintiff should not continue to have that right unless and until she renounces it or makes an acknowledgement inconsistent with it.' Whether the voluntary assumption of another nationality, for example, would suffice to constitute an 'acknowledgement inconsistent with it' is unclear.
As alluded to above, principles of constitutional interpretation were considered important by all of the judgments in Singh, and in two judgments in particular differences in approach were thought to be determinative. One of the key issues was the use of historical materials in interpreting constitutional terms. The Commonwealth questioned the appropriateness of taking into account the Convention Debates in this context, which precipitated some lengthy consideration by a number of the judges about the role of the Debates (and other historical references such as the state of the common law at federation) in construing a Constitution 'intended to endure'.
None of the judgments took the position that historical materials, such as the Convention Debates, are irrelevant. Rather, consistent with previous authority, it was reiterated that reference to the public record of the Convention Debates may be made, 'not for the purpose of seeking the subjective intention of people involved in the drafting', 'but for the purpose of identifying the contemporary meaning of language used, the subject to which that language was directed and the nature and objectives of the movement towards federation.' Even Kirby J acknowledged that '[r]egard may certainly be had to the framers' intentions'.
The key difference in approach was rather in respect of the extent to which the inquiry ends once the framers' (objective) intentions have been ascertained. Kirby J undoubtedly advocated a contemporary or evolutionary approach in the clearest terms. However, the joint judgment, as well as those of Gleeson CJ and McHugh J, acknowledged that consideration of historical material is not sufficient. For example, the joint judgment explained that while identifying the meaning of constitutional terms at federation is an 'essential step in the task of construction', the 'task does not end with the results of that inquiry'. Rather, '[a]lways, the Constitution is to be construed bearing steadily in mind that it is an instrument of government intended to endure'. In fact, the only real disagreement in this regard is with respect to Callinan J's clear preference for an originalist approach and concomitant rejection of an attempt to pay deference to evolving language and contemporary meaning of constitutional terms. In his Honour's view, in practice 'substantive linguistic change occurs very slowly' and, '[w]hen change does occur, it generally tends to relate to popular culture rather than to the expression of fundamental ideas, philosophies, principles and legal concepts.' Thus, judges should 'be especially vigilant to recognize and eschew what is in substance a constitutional change under a false rubric of a perceived change in the meaning of a word, or an expression used in the Constitution.' More fundamentally, however, given that power to amend the Constitution 'resides exclusively in the Australian people pursuant to s 128', Callinan J questioned whether, even if there were a change in the meaning of a word or phrase, the Court can 'justify a departure from its meaning at the time of Federation.' Thus, constitutional instruments 'are still basically to be construed by reference to the intentions of their makers objectively ascertained'.
On the basis of this outline of theoretical position, we might expect to observe quite divergent reasoning as between Callinan J on the one hand, and the remainder of the Court on the other. However what is perhaps most interesting about this apparent disagreement is the extent to which the judgments declined to implement in practice their preferred theoretical approach. In particular, despite the fact that both the joint judgment and that of McHugh J (the only two judgments to develop a criterion of 'alien') stated respectively that the 'Constitution is to be construed bearing steadily in mind that it is an instrument of government intended to endure', and that the Constitution should be interpreted keeping in mind the fundamental premise that the makers 'laid down a blueprint for the government of the nation for the indefinite future'; in fact both judgments rely solely on historical materials in developing their respective formulations of the key element of the term 'aliens'. Indeed, in neither judgment is the key characteristic, allegiance, as derived from historical sources, considered in light of its continuing appropriateness and relevance for contemporary conditions in Australian society. Thus, we may wonder what it means to say that the 'task does not end with the results of [the historical] inquiry'.
A number of the judgments acknowledged the feudal origins of the concept of allegiance between a subject and a sovereign power. As the joint judgment explained, the concept has its root 'in the feudal idea of a personal duty of fealty to a lord from whom land is held'. It was this history which prompted Gleeson CJ to observe in oral argument that part of the disagreement in Singh, and in previous decisions of the High Court with respect to the 'aliens' power, relates 'to whether or not the concept of alienage is tied to the feudal concept of subjection to a monarch or whether it is related to questions of citizenship and membership of the community.' Indeed, the joint judgment noted Gummow J's warning in a previous decision that care is required in 'treating what Holdsworth wrote of the position in England centuries ago respecting allegiance to the Crown as supplying in modern times a sufficient and adequate discrimen between subjects or citizens and aliens.' Yet their Honours nonetheless concluded that, since history demonstrates that by the end of the 19th century 'aliens' included those who owed allegiance to another sovereign power, 'allegiance to a foreign power' is today the discrimen of 'aliens' in the Australian Constitution.
Consideration of this historical position in light of the question whether the constitutional expression 'alien' has 'a different operation…100 years after federation', may well have yielded a different conception of the key characteristic of 'alien'. It is clear that, by the end of the 19th century, British law had not satisfactorily accommodated the notion of dual nationality. Yet, multiple nationality is now a widespread and well accepted phenomenon. The number of individuals holding multiple nationalities has continued to grow in recent decades internationally, and an estimated 4.4 million Australian citizens today are able lawfully to possess more than one citizenship. Indeed, the 2002 decision to repeal s 17 of the Australian Citizenship Act 1948 (Cth), which had provided that Australian citizens lost that status on acquiring a foreign nationality, reflected the view that this policy had become 'outmoded and discriminatory' and that, '[i]n a world of increasing mobility, it was considered anachronistic'. Moreover, it was acknowledged that there are many reasons why Australian citizens may wish to retain or acquire a foreign citizenship, for example for nostalgic reasons, or for practical considerations such as the existence of property rights in a foreign country, none of which necessarily cast doubt on a person's commitment to or connection with Australia. In light of these developments, the notion that foreign citizenship is the defining criterion of alienage for constitutional purposes does not arguably accord with modern realities. An approach which focused instead on the degree of membership or connection with the Australian community might have embodied a more modern conception of citizenship (or, to be more accurate, non-alienage).
It is also difficult to reconcile this approach with other decisions of the High Court which have considered the notion of 'allegiance' to a foreign power. In Singh, the criterion of 'allegiance to another sovereign power' was applied to the plaintiff in a fairly mechanical manner. That is, the mere fact of her Indian citizenship, conferred on her automatically at birth by operation of law, was considered sufficient by the joint judgment to establish her foreign allegiance, and thus alien status. However, in Sykes v Cleary, the High Court held that the mere fact of 'continuing to possess a foreign nationality' does not disqualify an Australian citizen for election to Parliament under s 44(i) of the Constitution (notwithstanding that s 44(i) provides that a citizen of a foreign power 'shall be incapable of being chosen as a member of Parliament'), as long as that person has taken 'all reasonable steps to renounce that nationality'. This implicitly assumes that the mere possession of a foreign nationality does not necessarily involve 'allegiance' to that foreign power. In reaching that conclusion in Sykes, Mason CJ, Toohey and McHugh JJ interpreted s 44(i) in light of the fact that it 'finds its place in a Constitution which was enacted at a time, like the present, when a high proportion of Australians, though born overseas, had adopted this country as their home'.
As explained above, it is well established that there must be some limit on the Commonwealth's ability to determine the scope of its own power by deciding who falls within the status 'alien'. In Singh, the Commonwealth sought to define such limits by identifying the 'core' of the notion of alienage, or, to be more accurate, non-alienage, which would be outside Commonwealth power. The argument was made that once such a 'core' could be identified, the 'penumbra' — or outer limits of the concept — would be within Parliament's power to regulate.
The Commonwealth conceded in oral argument that such a core (of non-alienage) would include, 'at least people who are born in Australia to parents who are Australian citizens, and it may well extend to people who are Australian permanent residents'. Thus, where conditions of both jus soli and jus sanguinis are present, a person presumably 'could not possibly answer the description of "aliens"'. However, as Kirby J observed in Singh, such concessions on behalf of the Commonwealth cannot 'necessarily be taken as binding future governments or parliaments'.
Ultimately, as explained above, the joint judgment preferred to identify the 'central characteristic' of the status alien by reference to foreign allegiance. While only three of the five majority judges in Singh formulated a specific test or criterion for assessing whether a person is properly within the 'aliens' power, in Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Ame ('Ame'), handed down on 4 August 2005, a joint judgment comprising six judges held that the consequence of Singh is that, 'the legal status of alienage has as its defining characteristic the owing of allegiance to a foreign sovereign power'.
The challenge is to ascertain how that determining characteristic assists in delimiting the scope of Parliament's power. For example, what does the central characteristic of 'foreign alienage' tell us about whether or not the Commonwealth can legislate to alter existing citizenship laws so as to provide that all persons born outside Australia (regardless of parentage) are no longer capable of obtaining citizenship? Or, to use an example which was far more troubling for a number of judges in oral argument in Singh, can Parliament legislate to denationalize all Australian-born citizens who have at least one foreign-born parent, grandparent or great grandparent? Would the answer depend on whether there was a racial element to such a policy?
If citizenship is a mere statutory benefit, then, according to existing authority, Parliament may legislate to withdraw it. On the other hand, if the conferral of statutory citizenship also carries with it (either alone or in conjunction with other indicia of connection to the Australian community) conferral of the status of non-alien, and/or some kind of constitutional nationality, then Parliament's power to alter such constitutional status (by amending the Australian Citizenship Act) may be limited. This highlights the continuing importance of the question whether there is some essential/core/immutable notion of alien (and its converse non-alienage) beyond that identified in Singh. Two specific manifestations of this uncertainty, namely the categories of stateless persons and dual citizens, will first be considered, before turning to deprivation of citizenship more generally.
In principle, since a stateless person does not enjoy the citizenship or nationality of any state, it is difficult to understand how such a person could be said to owe allegiance to a 'foreign sovereign power'. However it is important to note that in the joint judgment in Singh, their Honours concluded that what had remained unaltered throughout the 19th century was that 'aliens' included those who owed allegiance to another sovereign power, 'or who, having no nationality, owed no allegiance to any sovereign power.' Further, it is implicit in Kirby J's decision in Singh that a stateless person also falls within the aliens power, since, as mentioned above, his Honour found that it was unclear that Singh had in fact acquired Indian citizenship.
Notwithstanding this, it is still open to question whether Singh, on its proper reading, can be said to foreclose an argument that a stateless person born in Australia is outside the scope of the aliens power. The joint judgment in Singh sought to establish 'what it is that gives a person the status' of alien, and in doing so, emphasized repeatedly that what gives a person that status is 'owing obligations to another sovereign power'. As explained above, this essential characteristic was largely derived from historical analysis which revealed that, by the end of the 19th century, the one constant feature of the term 'aliens' was that 'the alien "belonged to another"'. It is less clear whether historical analysis supports the view that the term also included stateless persons, particularly given that, as Gummow J noted in Al-Kateb, the phenomenon of stateless persons 'achieved significance only in the course of the twentieth century'. The conclusion that the reference to stateless persons in Singh thus constitutes obiter is strengthened when one considers that the joint judgment in Ame confirmed that 'the legal status of alienage has as its defining characteristic the owing of allegiance to a foreign sovereign power.'
In a post-Singh decision which considered its application to stateless persons, the Full Federal Court noted that the joint judgment in Singh 'concentrated on the central notion' of foreign allegiance. However, the Court took the view that there was nothing in the joint judgment in Singh contrary to the proposition that a stateless person is an alien. Significantly, the Court proceeded to explain that the applicant was an alien, 'simply because, like a citizen of a foreign country, a stateless person lacks any constitutionally significant relationship with Australia'. However, this appears to depart from the reasoning in Singh, since none of the majority judgments purported to define the status 'alien' by reference to a person's connection to or relationship with Australia. The Full Federal Court's analysis suggests that one must identify a set of positive features that constitute the core or essential characteristics of non-alien, that is, the content of a 'constitutionally significant relationship', in order to ascertain whether a person is outside the ambit of the aliens power. The fact that the Full Federal Court adopted this approach may indicate the limitations of the 'foreign allegiance' criteria in further defining the parameters of the aliens power. The referral of Koroitamana to a Full Bench of the High Court indicates that serious questions remain concerning the application of Singh to the category of stateless persons.
Another uncertain category following Singh is that of dual nationals, that is, those Australian citizens who also 'owe allegiance to a foreign power'. Once an exclusive criterion (owing allegiance elsewhere) rather than an inclusive criterion (owing allegiance to Australia; membership of the Australian community) is adopted, the mere fact of foreign citizenship would appear to render a person an 'alien' within the meaning of the Constitution. Indeed, so much appears to have been confirmed by Kirby J in Ame, where his Honour noted that once the plaintiff had become a citizen of a foreign state (in that case Papua New Guinea):
in accordance with Singh, it was competent for the Australian Parliament…to provide for the termination of the applicant's statutory status of Australian citizen…It did not have to do so. It might have provided for dual citizenship (a later legal development in Australia). But as a matter of constitutional power, the legal entitlement existed.
The practical significance of this is that it would presumably be open to Parliament to legislate for the automatic removal of Australian citizenship of all persons who have or acquire a foreign nationality, regardless of the circumstances in which the foreign citizenship was acquired, and regardless of the individual's ability to divest himself or herself of that foreign nationality. It may be that a dual national who had a sufficient connection with Australia (for example, who was born in Australia to Australian parents) could be said to 'not possibly answer the description of alien'; however this would be difficult to elicit from the reasoning in Singh.
The Court was presented with the opportunity to consider, in the post-Singh context, the scope of Parliament's power to withdraw statutory citizenship in Ame. The background to the case was that following the achievement of Papuan independence in 1975, the Governor-General promulgated regulations, pursuant to s 6 of the Papua New Guinea Independence Act 1975 (Cth), which provided that persons who became citizens of the Independent State of Papua New Guinea on Independence Day ceased to be Australian citizens.
The applicant in Ame submitted that Parliament 'lacked the legislative capacity to deprive the applicant of his Australian citizenship' in this manner. In particular, it was argued that there is a limitation inherent in s 51 (xix) 'that prevents that power from being applied unilaterally (that is, without the consent of the individual manifested by renunciation or some similar act) to change a person's status' from non-alien to alien. Further, it was submitted that all Commonwealth legislative powers were constrained by a 'broader constitutional principle that prevented the Federal Parliament and the Executive Government of the Commonwealth from depriving a person such as the applicant of his fundamental constitutional status as an Australian national ("citizen")'; a status described 'by reference to the provisions in the Constitution referring to a "subject of the Queen" or the notion of the "people of the Commonwealth".'
The joint judgment (of six judges) focused on the asserted limitation on s 51(xix) and emphasized that this issue did not directly arise since the Court was concerned only with 'whether any such limitation exists in relation to the inhabitants of external territories', that is, with s 122 of the Constitution. Thus, '[w]hat follows is to be understood in that context'. Notwithstanding this caveat, however, the joint judgment immediately noted that, '[i]n any event, no limitation of the kind proposed applies to the power conferred by s 51(xix).' In particular:
In Singh, a majority of the Court rejected the view that concepts of alienage and citizenship describe a bilateral relationship which is a status, alteration of which requires an act on the part of the person whose status is in issue.
This would appear to be at least an implicit rejection of the view expressed by Gaudron J in Taylor that the Parliament's power to deprive a person of Australian citizenship can only be exercised 'by reference to some change in the relationship between the individual and the community.' It is also a clear (although not explicit) rejection of the US position which holds that the constitutional guarantee of citizenship may be lost only where a person 'voluntarily relinquishes that citizenship'.
Justice Kirby agreed with the joint judgment in Ame as to the answers to the stated questions in that case; however, his Honour was far more troubled by the question of limits on Commonwealth power to withdraw citizenship. His Honour observed that:
The deprivation of nationality, including nationality by birth and especially in cases affecting minority ethnic communities, has been such a common affront to fundamental rights that I would not, without strong persuasion, hold it to be possible under the Constitution of the Australian Commonwealth.
Given the particular position of external territories in the constitutional structure, the question of Parliament's broader power to withdraw citizenship for those in internal territories, or indeed more generally, did not arise in that case. However, it is clear from Kirby J's judgment that his Honour considers that there remains a concept of constitutional nationality, since his Honour emphasized that the outcome in Ame 'affords no precedent for any deprivation of constitutional nationality of other Australian citizens whose claim on such nationality is stronger in law and fact than that of the applicant.' It is not clear precisely what this notion of constitutional nationality would comprise. However, the emphasis on 'law and fact' and the fact that Kirby J distinguished the 'fragile and strictly limited character of the "citizenship" of Australia which the applicant previously enjoyed' (a limited form of citizenship that did not even allow for automatic entry into Australia) from 'other circumstances of local nationality having firmer foundations', suggests that identifying the content would involve a qualitative assessment of the nature of a person's connection with Australia, including (previously enjoyed) statutory rights. Similarly, it is not clear precisely what the consequences would be of attaining such constitutional status, although some indication is provided in the reference to 'rights of due process that might arise' in cases of local nationality with former foundations. Ultimately however we are left with the conclusion that while there are 'fundamental notions of nationality, sufficiently expressed or necessarily implied, in the Australian Constitution', the 'limited and special circumstances of the applicant's case do not require the refinement of such limitations.'
The recent High Court decisions in Singh and Ame address two of the most fundamental questions pertaining to Australian citizenship law today. The first is the criterion for defining the status 'alien' and in particular the degree to which the Commonwealth's ability to define that status is 'at large'. This case-note has argued that the formulation adopted by a majority of the Court is open to criticism on the basis that it is derived solely from historical sources without regard to its contemporary relevance, and that its practical application to various categories of persons remains uncertain and problematic. The second question is whether, assuming there is a constitutional category of non-alien, Parliament can unilaterally change a person's status from non-alien to alien. Previous authority established that Parliament alone retains the power to determine the conditions on which a person may be naturalized; in other words that a person cannot change status from alien to non-alien merely by 'absorption' into the Australian community (without undergoing a process of naturalization). However, following Ame, it remains unclear whether Parliament enjoys an equally unilateral power to alter a person's status from non-alien to alien; or whether some limitations exist to circumscribe Parliament's power. While these cases have thus provided some insight into the nature and extent of Commonwealth power, we must depend upon future jurisprudence to develop a coherent, contemporary theory of constitutional membership in the Australian body politic.
[∗] BComm (Hons) LLB (UNSW), LLM SJD (Michigan), Senior Lecturer, University of Melbourne. I am grateful for the comments of Kim Rubenstein, Simon Evans, Graeme Hill and the anonymous reviewer for the Federal Law Review on an earlier draft of this paper.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355.
 See Nolan v Minister for Immigration and Ethnic Affairs  HCA 45; (1988) 165 CLR 178, Re Patterson; Ex parte Taylor (2001) 207 CLR 391, and Shaw v Minister for Immigration and Multicultural Affairs  HCA 72; (2004) 203 ALR 143.
 As Fullagar J explained in Australian Communist Party v Commonwealth  HCA 5; (1951) 83 CLR 1, 258: 'A power to make laws with respect to lighthouses does not authorize the making of a law with respect to anything which is, in the opinion of the law-maker, a lighthouse'. This quote was cited by Gummow, Hayne and Heydon JJ in Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 402 , where their Honours stated that '[i]t is nonetheless important to emphasise the point made by Fullagar J … by reference to the metaphor that a stream cannot rise higher than its source'.
 See the Australian Constitution, s 51(xxi). In Singh, McHugh J noted the similarity between the aliens power and marriage power in this respect: Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 371 . As Brennan J noted in Fisher v Fisher  HCA 61; (1986) 161 CLR 438, 455: 'Although the nature and incidents of a legal institution would ordinarily be susceptible to change by legislation, constitutional interpretation of the marriage power would be an exercise in hopeless circularity if the Parliament could itself define the nature and incidents of marriage by laws enacted in purported pursuance of the power. The measure of the legislative power cannot be determined by reference to the occasions of its purported exercise'. This passage is cited in Dan Meagher, 'The Times are they A-Changin'? — Can the Commonwealth Parliament Legislate for Same Sex Marriages?' (2003) 17 Australian Journal of Family Law 134, 152, in which the author discusses the difficulty in defining the marriage power.
 Australian Constitution, s 51(xviii): 'Copyrights, patents of inventions and designs, and trade marks'. For recent High Court authority on interpreting this provision, see Grain Pool of Western Australia v Commonwealth (2000) 202 CLR 479.
 Australian Constitution, s 51(xvii). See Storey v Lane  HCA 47; (1981) 147 CLR 549 for discussion of Parliament's power to extend the ambit of bankruptcy legislation, especially at 558 (Gibbs CJ).
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 417 –. Kirby J pointed to a 2003 amendment to the Citizenship Act 1955 (India) which would have affected Singh's Indian citizenship, however it was not clear whether the amendment had been passed at the relevant time.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 356  (Gleeson CJ); 400  (Gummow, Hayne and Heydon JJ); 433  (Callinan J). I note that McHugh J did not appear to refer to this issue.
 Australian Citizenship Act 1948 (Cth), s 10(2).
 Rubenstein explains that s 10 of the Australian Citizenship Act 1948 (Cth) previously provided that 'people born in Australia between 26 January 1949 and 20 August 1986 were Australian citizens provided their father (later parent) was not a diplomat' or enemy alien: Kim Rubenstein, Australian Citizenship Law in Context (2002) 90.
 Australian Citizenship Council, Australian Citizenship for a New Century (2000) 40, cited in Rubenstein, ibid 93.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 370  (McHugh J).
 Ibid 370  (McHugh J).
 Compare the 14th Amendment to the United States Constitution which relevantly provides: '[a]ll persons born or naturalized in the United States and subject to the jurisdiction thereof, are citizens of the United States and of the State wherein they reside': United States Constitution amend XIV, § 1.
 However, the Australian Citizenship Act 1948 (Cth) is said to be supported by various powers, including 'naturalization and aliens' and an 'implied nationhood power': see Rubenstein, Australian Citizenship, above n 10, 71–74. For the most recent judicial exposition of the basis of the Citizenship Act 1948 (Cth), see Hwang v Commonwealth; Fu v Commonwealth  HCA 66; (2005) 222 ALR 83, 86 , 89  (McHugh J).
 See the Australian Constitution, s 24. See also s 7 ('people of the State').
 Ibid s 117.
 Re Patterson; Ex parte Taylor (2001) 207 CLR 391, 480 (Kirby J).
 See Australian Citizenship Act 1948 (Cth).
 Australian Constitution s 51(xxvii).
 Australian Constitution s 51(xxix).
 The common law position was said to have been restated and explained in Calvin's Case (1608) 7 Co Rep 1a; 77 ER 377 in which Coke CJ 'applied the common law rule that a person cannot be a natural born subject unless the place of his or her birth, at the time of his or her birth, was within the King's dominions': Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 378  (McHugh J).
 See Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 419–20 – (Kirby J).
 Ibid 421 .
 Ibid 409 –. See also Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 10 February 2004) 43.
 See Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 10 February 2004) 41–2.
 See also ibid 57, where the Commonwealth criticized the plaintiff's submission which was said to depend upon the term 'alien', 'being frozen in 1900'.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 357 , citing Re Minister for Immigration and Multicultural Affairs; Ex parte Te (2002) 212 CLR 162, 173 .
 Ibid, citing Chu Kheng Lim v Minister for Immigration, Local Government and Ethnic Affairs (1992) 176 CLR 1, 25.
 Ibid 357 .
 Ibid 357 , emphasis added, citing Pochi v Macphee  HCA 60; (1982) 151 CLR 101, 109.
 Ibid 366 .
 Ibid 367 .
 Their Honours did not set out their reasoning as a syllogism; however, their reasoning is encapsulated in summary form at ibid 400  and 416 .
 Ibid 412 .
 Ibid 414 .
 In this respect it should be noted that the joint judgment appeared to call into question the utility of engaging tools such as connotation/denotation or concepts/conceptions. Their Honours stated that while such tools might be thought useful, '[t]here is at least a risk, however, that using such tools directs attention to their content and to their utility rather than to the analytical task they are being used to undertake': ibid 404 .
 Potter v Minahan  HCA 63; (1908) 7 CLR 277, 289 (Griffith CJ); see also 293 (Barton J) and 304–5 (O'Connor J).
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 389–95 (McHugh J).
 For example Potter v Minahan (above n 40) involved the immigration power: ibid 415 .
 After setting out the plaintiff's arguments based on historical materials, Kirby J concluded that, '[f]or me, that word [aliens], like every other word in the Constitution, is not frozen in whatever meaning it may have had in 1901. Thus, for me, this case is primarily about the proper approach to constitutional construction': ibid 426 .
 Ibid 427 .
 Ibid 427 .
 Ibid 428 .
 Ibid 431 .
 Ibid 369 . It should be noted that, unlike the joint judgment, McHugh J's reasoning is explicitly expressed as a polysyllogism.
 McHugh J acknowledged that this is a result of evolution, that is, when the Crown 'divided', 'the denotation of the term "subject of the Queen" changed' so as to refer to the Queen of Australia: ibid 375 .
 Ibid 369 .
 Ibid 379–80 .
 Ibid 387 .
 Ibid 387 .
 Ibid 389 .
 Pochi v Macphee  HCA 60; (1982) 151 CLR 101, 109.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 393 .
 His Honour explained that: '[N]one of the naturalization power, the implied nationhood power or the external affairs power empowers the parliament to deprive a non-alien of her constitutional citizenship by an enactment such as s 10 [of the Citizenship Act]': ibid 399 .
 McHugh J stated that, 'birth within Australia makes a person a member of the Australian community who comes under an obligation to obey its laws and is correlatively entitled to all the rights and benefits which membership of the community involves': ibid 398 . However, it is by no means clear that this would equate a constitutional citizen to a statutory citizen, since much legislation confers particular benefits on statutory citizens only. For a description of such legislation, see Rubenstein, Australian Citizenship, above n 10, Chapter Five.
 Ibid 436–37 .
 Ibid 440 , citing 'Report of the Royal Commissioners for Inquiring into the Laws of Naturalization and Allegiance (1869)' in Reports from Commissioners, 1868–69, vol 14, 607, 614–15.
 Ibid 440 –.
 Ibid 444 .
 Ibid 426  (Kirby J) and 436–437 – (Callinan J).
 It is not clear what were the exact arguments of the Commonwealth in this respect. In oral argument, Kirby J asked the Solicitor-General for the Commonwealth whether he persisted with his objection to the use of the Convention Debates, to which the Solicitor-General replied that objection was 'too strong a word' and that the submission was merely that the material did not assist the Court and is not 'within the range of material that the Court is assisted by in looking at the debates to construe the Constitution': Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 10 February 2004) 60. It seems likely that the objection was directed to the fact that, since the plaintiff sought to rely on the Convention Debates to establish that at least some delegates were against the insertion of a specific citizenship power because, 'the parliament could [then] legislate to deprive a person of his or her citizenship', (Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 388  (McHugh J); Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 10 February 2004) 11–12), this effectively involved 'substituting for the meaning of the words used the scope and effect…which the founding fathers subjectively intended' — an inappropriate use of the Convention Debates: Cole v Whitfield  HCA 18; (1988) 165 CLR 360, 385.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 403  (Gummow, Hayne, Heydon JJ). See also 363–6 (Gleeson CJ), 374–5 (McHugh J) and 435–7 (Callinan J).
 Ibid 36  (Gleeson CJ), citing Cole v Whitfield  HCA 18; (1988) 165 CLR 360, 385. See also Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 374  where McHugh J explained that the Debates may be relied upon to 'identify the mischief to which the words of the Constitution were directed, to identify the purpose of the relevant constitutional concept or to determine the specialized meaning of constitutional terms'. Similarly, the joint judgment emphasized that the task of construction cannot be undertaken 'without knowing what particular constitutional expressions meant, and how words were used, at the time of federation': ibid 403 . See also ibid 436  (Callinan J), citing Cole v Whitfield  HCA 18; (1988) 165 CLR 360, 385.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 426 .
 His Honour explained: '[T]he ambit of the power is not limited by the wishes, expectations or imagination of the framers. They did not intend, nor did they enjoy the power, to impose their wishes and understanding of the text upon later generations of Australians': ibid 426 . Rather, the Court 'should construe this power [naturalization and aliens] with all the generality that the words used in the Constitution admit, as those words are understood today': ibid 427 .
 Ibid 403 .
 Ibid. See also ibid 360  where Gleeson CJ states that context includes, 'developments, over time, in the national and international context in which the instrument is to be applied'. Further, his Honour explained that: 'Changing times, and new problems, may require the court to explore the potential inherent in the meaning of the words, applying established techniques of legal interpretation': ibid 362 . See also ibid 373  (McHugh J).
 Ibid 436 .
 Ibid 437  (emphasis added).
 Ibid 403  (Gummow, Hayne and Heydon JJ).
 Ibid 373  (McHugh J).
 In this respect the reasoning is similar to that adopted by the Court in Cheatle v The Queen  HCA 44; (1993) 177 CLR 541 regarding unanimous jury verdicts in the context of s 80 of the Constitution. Indeed in Singh, Gleeson CJ reiterated the importance of the Cheatle approach of identifying an 'immutable' characteristic by reference to historical materials: Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 364–6 –.
 I note that other writers have also observed that differences in approaches to constitutional interpretation do not necessarily lead to differences in result in particular cases: see Graeme Hill, '"Originalist" vs "Progressive" Interpretations of the Constitution — Does it Matter?' (2000) Public Law Review 159.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 405 . During the medieval period, as McHugh J explains, 'all persons within the King's dominions owed a duty of allegiance to the King': ibid 376 . This was because the common law 'recognized the sovereign as the supreme feudal lord of the people as well as the land': ibid 376 . Thus, '[s]ubjects owed the King the same duties of fidelity and obedience as vassals owed to their lord, for the King was the sovereign lord': ibid. See also at 404–5  (Gummow, Hayne and Heydon JJ), reciting essentially the same history; and at 421  and 430 – (Kirby J).
 Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 11 February 2004) 4.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 405  (emphasis added), citing Re Minister for Immigration and Multicultural Affairs; Ex parte Te (2002) 212 CLR 162, 196–9. Indeed, I note that in Ex parte Te, Gummow J stated that allegiance 'supplies no such discrimen [between subjects and aliens] in modern times': 212 CLR 162, 196 .
 It should be emphasized that Gummow J in Ex parte Te (and the joint judgment in Singh) was criticizing the concept of allegiance in the context of the argument that an alien should be defined as a person who does not owe allegiance to the Crown. However, relying on allegiance to a foreign power as the discrimen is equally open to the criticism that it relies on feudal notions of allegiance to a sovereign entity; rather than for example membership of or connection to Australia.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 404  (Gummow, Hayne and Heydon JJ). Their Honours explained that: 'Numerous cases decided by this court reveal that constitutional expressions may have a different operation 50 or 100 years after federation from the operation they would have had in 1901', citing Sue v Hill  HCA 30; (1999) 199 CLR 462 and Grain Pool of Western Australia v Commonwealth (2000) 202 CLR 479 as examples.
 Ibid 383  (McHugh J). See also ibid 410  where it is noted by Gummow, Hayne and Heydon JJ that despite acknowledgement of the problem in the 19th century, 'the wider problems of dual or multiple nationality remained unresolved.' It is also interesting to note that the problem of the 'foreign allegiance' criterion vis-à-vis dual nationality was acknowledged in oral argument. For example, Hayne J noted that if the focus is on 'whether allegiance is owed…to the foreign state', then 'we begin to get into difficulties, one when we introduce more modern concepts of dual nationality': Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 11 February 2004) 10. As his Honour noted, 'the duality of obligation is something that was not countenanced': ibid.
 While there were early (failed) attempts in international law to discourage or abolish multiple nationality, it now recognized to be 'a fact of international life': John R Dugard, International Law Commission, First Report on Diplomatic Protection, –, UN Doc A/CN–4/506 (2000). For example, the attitude of European states in the 1960s was that multiple nationality should be discouraged, since cases of multiple nationality 'are liable to cause difficulties' and thus 'joint action to reduce as far as possible the number of cases of multiple nationality […] corresponds to the aims of the Council of Europe': Preamble to the Convention on Reduction of Cases of Multiple Nationality and Military Obligations in Cases of Multiple Nationality, ETS 43 (entered into force 28 March 1968). However, 30 years later, the 1997 European Convention on Nationality, ETS 166 (entered into force 3 January 2000) not only permits contracting states to provide for multiple nationality but also positively requires recognition in certain closely circumscribed cases.
 Aleinikoff and Klusmeyer for example note that 'there is no denying that its [multiple nationality] incidence is widespread and growing', citing recent studies which reveal the extent of the increase in the phenomenon of multiple nationality internationally: T Alexander Aleinikoff and Douglas Klusmeyer, 'Plural Nationality: Facing the Future in a Migratory World' in T Alexander Aleinikoff and Douglas Klusmeyer (eds), Citizenship Today: Global Perspectives and Practices (2001) 63.
 Australian Citizenship Council, Australian Citizenship for a New Century (2000) 60–61.
 Section 17 of the Act provided that an Australian citizen aged 18 or over who does 'any act or thing, the sole or dominant purpose of which and the effect of which is to acquire the nationality or Citizenship of a foreign country shall…cease to be an Australian citizen': ibid 60. Section 17 was repealed by the Australian Citizenship Legislation Amendment Act 2002 (Cth).
 This was the view of the Joint Standing Committee on Migration (Parliament of the Commonwealth of Australia, Joint Standing Committee on Migration, Australians All: Enhancing Australian Citizenship (1994)), as cited in Rubenstein, Australian Citizenship, above n 10, 142. These criticisms also related to the fact that prior to the amendment, persons born with another citizenship but who acquired Australian citizenship could retain both nationalities; but once a person was an Australian citizen, he/she could not acquire another citizenship: see Rubenstein, Australian Citizenship, above n 10, 142.
 Australian Citizenship Council, above n 93, 61.
 As the Australian Citizenship Council stated: 'The law and practice of most countries with which Australia likes to compare itself permits citizens of those countries to obtain another citizenship without losing their original citizenship…These countries simply recognize that they have an internationally mobile population and that they can retain connection with this population even if another citizenship is acquired': ibid 65, cited by Rubenstein, Australian Citizenship, above n 10, 142.
 This was implicitly acknowledged by Kirby J in Singh v Commonwealth, although in the context of responding to the plaintiff's argument that 'alien' should be interpreted as a person who does not owe allegiance to the Queen of Australia. His Honour noted that: 'Constitutional notions of membership of the Australian community, and of who constitute the "people of the Commonwealth", have kept pace with these [international and national] changes. It is unrealistic, indeed highly artificial, to conceive of such membership today in feudal terms': Singh v Commonwealth  HCA 43; (2004) 209 ALR 355 at 430 .
 Gaudron J conceived the resolution of the scope of the aliens power to involve questions of 'membership of the community constituting the Australian body politic': Nolan v Minister for Immigration and Ethnic Affairs  HCA 45; (1988) 165 CLR 178, 189. In Taylor she reiterated that, 'an alien is "a person who is not a member of the community which constitutes the body politic of the nation state from whose perspective the question of alien status is to be determined"': Re Patterson; Ex parte Taylor (2001) 207 CLR 391, 407. See also Kim Rubenstein, 'Meanings of Membership: Mary Gaudron's Contributions to Australian Citizenship', (2004) 15 Public Law Review 305, 306. Of course, Gaudron J's approach has never been accepted by a majority of the Court. I note that at one stage of the oral argument in Singh, the Commonwealth submitted that the power to pass laws with respect to 'aliens' means the power to pass laws about people who do not have 'the necessary relationship with the polity to be members of it': Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 11 February 2004) 11. It is also interesting that the concept of citizenship or nationality has been similarly conceived by the International Court of Justice: 'nationality is a legal bond having at its basis a social fact of attachment, a genuine connexion of existence, interests and sentiments, together with the existence of reciprocal rights and duties': Liechtenstein v Guatemala ('Nottebohm Case')  ICJ 4, 23, as cited in Sykes v Cleary  HCA 60; (1992) 176 CLR 77, 107 (Mason CJ, Toohey and McHugh JJ).
 As the joint judgment explained in summarizing their Honours' argument: 'As a citizen of India the plaintiff has obligations, "owes allegiance", to a nation other than Australia. She is, therefore, a person within the class referred to in s 51(xix) as "aliens"': Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 400 .
 Sykes v Cleary  HCA 60; (1992) 176 CLR 77, 107 (Mason CJ, Toohey and McHugh JJ); see also 113 (Brennan J), 131 (Dawson J).
 For example, in Sykes v Cleary, Mason CJ, Toohey and McHugh JJ state that, 'it would be wrong to interpret the constitutional provision in such a way as to disbar an Australian citizen who had taken all reasonable steps to divest himself or herself of any conflicting allegiance': ibid 107.
 See Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 10 February 2004) 43: 'there is a limitation on that power where one trespasses on core concepts'.
 This presumably draws on the work of legal theorist H L A Hart who observed that, in legal interpretation, especially constitutional interpretation, '[t]here must be a core of settled meaning, but there will be, as well, a penumbra of debatable cases in which words are neither obviously applicable nor obviously ruled out': 'Positivism and the Separation of Law and Morals' (1958) 71(4) Harvard Law Review 593, 607. Interestingly, however, he did not use this dichotomy to explain the respective roles of court and legislature; rather to explore the relationship between law and morality: see at 608.
 Transcript of Proceedings, Singh v Commonwealth (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan, Heydon JJ, 10 February 2004) 44.
 Pochi v Macphee  HCA 60; (1982) 151 CLR 101, 109.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 431 .
 In particular, the joint judgment noted: 'It may be doubted whether metaphorical references to the "penumbra" of the meaning of a constitutional expression or, as it was put in oral argument, the "core" meaning of a constitutional expression, can be of great assistance in any task of constitutional interpretation': ibid 401–2 .
 Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Ame  HCA 36; (2005) 218 ALR 483, 495  (Gleeson CJ, McHugh, Gummow, Hayne, Callinan and Heydon JJ) (emphasis added).
 Kartinyeri v Commonwealth  HCA 22; (1998) 195 CLR 337, 355–356 , 375–376 – (cf 421–422). See also ibid 509  (Kirby J).
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 412  (emphasis added).
 Indeed, this authority was relied upon by Hayne J in a post-Singh decision dismissing an application for order nisi by a stateless person otherwise in a similar situation to Singh. His Honour acknowledged that the central characteristic of alienage was identified in Singh as 'owing obligations (allegiance) to a sovereign power other than the sovereign power in question'; but reasoned that the fact of that 'central characteristic' does not 'deny the proposition which otherwise underpinned the decision of at least a majority of the Court in Singh that the aliens power' extends to stateless persons: Transcript of Proceedings, Applicant A269/2003; Ex parte – Re Manager Baxter Immigration Detention Centre  HCATrans 570 (High Court of Australia, Hayne J, 13 December 2004) 19. It should also be noted that Hayne J was not satisfied that the applicant in that case would, in any event, 'be regarded by Afghani authorities as stateless': at 18.
 Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 414 . See also at 402 : 'These reasons seek to demonstrate that a central characteristic of the status "alien" is, and always has been, owing obligations to a sovereign power other than the sovereign power in question' (Gummow, Hayne and Heydon JJ).
 Ibid 412 .
 Al-Kateb v Godwin  HCA 37; (2004) 208 ALR 124, 146 .
 Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Ame  HCA 36; (2005) 218 ALR 483, 495  (emphasis added).
 Koroitamana v Commonwealth of Australia  FCAFC 61; (2005) 142 FCR 391, 392 .
 Ibid (emphasis added).
 I note that in Singh v Commonwealth  HCA 43; (2004) 209 ALR 355, 430  Kirby J made some reference to '[c]onstitutional notions of membership of the Australian community, and of who constitute the "people of the Commonwealth"'; however, as explained above, his Honour does not purport to define 'non-alien'/'alien' by reference to such notions since he did not in fact devise a core definition.
 See Koroitamana & Anor v Commonwealth  HCATrans 782 (30 September 2005) (McHugh and Callinan JJ).
 Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Ame  HCA 36; (2005) 218 ALR 483, 515  (Kirby J).
 Pochi v Macphee  HCA 60; (1982) 151 CLR 101, 109.
 Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Ame  HCA 36; (2005) 218 ALR 483, 489  (Gleeson CJ, McHugh, Gummow, Hayne, Callinan and Heydon JJ).
 Ibid 495  (Gleeson CJ, McHugh, Gummow, Hayne, Callinan and Heydon JJ). I note that in the reported version of this decision, the applicant's argument is framed as a limitation 'that prevents that power from being applied unilaterally (that is, without the consent of the individual manifested by renunciation or some similar act) to change a person's status from alien to non-alien': ibid, 495 . However, this is a mistake, as the applicant's argument was clearly that he had attained the status of non-alien (by virtue of being accorded statutory citizenship at birth) which could not unilaterally be altered to alien.
 Ibid 509  (Kirby J).
 Ibid 495 .
 Ibid 495 .
 Ibid 496 .
 Re Patterson; Ex parte Taylor (2001) 207 CLR 391, 411. See also Gaudron J's views in Nolan v Minister for Immigration and Ethnic Affairs  HCA 45; (1988) 165 CLR 178, 193, where her Honour stated: 'As the transformation from non-alien to alien requires some relevant change in the relationship between the individual and the community, it is not, in my view, open to the Parliament to effect that transformation by simply redefining the criterion for admission to membership of the community constituting the body politic of Australia'. See also Rubenstein, 'Meanings of Membership' above n 99, 307. It may be that the particular facts in Ame can be reconciled with Gaudron J's views if her Honour can be assumed to have used 'community' interchangeably with 'polity', since it could be argued that Papua New Guinea’s independence constituted a change in the relationship between the individual and the polity in that case. However, the broad language used by the Court in Ame appears to go beyond the facts in that case to reject entirely the notion that citizenship 'describe[s] a bilateral relationship which is a status, alteration of which requires an act on the part of the person whose status is in issue':  HCA 36; 218 ALR 483, 495 .
 The joint judgment does not refer at all to the American authority.
 Afroyim v Rusk,  USSC 132; 387 US 253, 268 (1967). See also Vance v Terrazas  USSC 40; 444 US 252 (1984). This authority had been relied upon by the applicant in Ame, as providing appropriate analogous principles notwithstanding the different constitutional context of the US: Transcript of Proceedings, Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Ame  HCATrans 66 (High Court of Australia, Gleeson CJ, McHugh, Gummow, Kirby, Hayne, Callinan and Heydon JJ, 3 March 2005) 52–53.
 Re Minister for Immigration and Multicultural and Indigenous Affairs; Ex parte Ame  HCA 36; (2005) 218 ALR 483, 510–11 .
 Ibid 511–13 –.
 Ibid 516  (emphasis added).
 Ibid 516 .
 Ibid 516–7 .
 See Shaw v Minister for Immigration and Multicultural Affairs  HCA 72; (2003) 203 ALR 143, 145 (Gleeson CJ, Gummow and Hayne JJ): 'The "ordinary understanding" of the term "alien", correctly, is not said to be at large.'
 See Pochi v Macphee  HCA 60; (1982) 151 CLR 101, 111. This was affirmed in Re Minister for Immigration and Multicultural Affairs; Ex parte Te (2002) 212 CLR 162, 171  (Gleeson CJ), 179  (Gaudron J), 188  (McHugh J), 195  (Gummow J), 219–20  (Hayne J). However, I note that Kirby J accepted that there might be 'extreme' cases in which 'non-citizens, who were long-term residents although never naturalized (often for legitimate reasons) might exceptionally be regarded as outside the aliens power': 217–8 . In addition, Callinan J did not hold that an alien can never become a non-alien by absorption –only that in this case no such absorption had occurred: 228 .