I. From Maxim to General Principle: The Evolution of Lex Specialis

Laws often contain related rules, and when more than one law or rule applies, conflicts may arise. Lex specialis is one of the commonly invoked principles—the others being lex superior and lex posterior—to resolve such conflicts. The maxim “lex specialis derogat legi generali” dates to Roman times. The renowned Roman jurist Papinian wrote in Questions Book 33 that “in the whole of law, species takes precedence over genus, and anything that relates to species is regarded as the most important.”Footnote ⁷ Hugo Grotius, father of international law, explained in On the Law of War and Peace that

Emmerich de Vattel, the prominent Swiss jurist, similarly maintained in The Law of Nations that specific provisions should prevail because “special matter admits of fewer exceptions than that which is general; it is enjoined with greater precision, and appears to have been more pointedly intended.”Footnote ⁹ Karl Larenz, the influential German legal philosopher, further elaborated in Methodology of Law that when a special rule and a general rule are mutually exclusive, the special rule displaces the general rule because “in the opposite case, the special rule would have no application at all.”Footnote ¹⁰

The lex specialis principle is widely recognized in domestic legal systems across civil law jurisdictions. For instance, Article 15 of the Italian Penal Code provides that “[w]hen multiple criminal laws or multiple provisions of the same criminal law regulate the same subject, the law or provision of a special law prevails over the law or provision of a general law, unless otherwise provided.”Footnote ¹¹ Similarly, Article 103 of the Legislation Law of the People’s Republic of China (enacted in 2000, revised in 2015 and 2023) stipulates that

Moreover, Article 6(3) of the Civil Code of the Macao Special Administrative Region of the People’s Republic of China states that “the general law does not repeal the special law, except if there is an unequivocal intention of the legislator to the contrary.”Footnote ¹³ In addition, Article 5(1) of the General Act on Public Administration of South Korea reads that “except as otherwise provided in other statutes, this Act shall apply to administration.”Footnote ¹⁴

Unlike domestic law, international law lacks a centralized legislative authority. International rules are formulated by diverse actors at different times and through varying processes, increasing the likelihood of norm conflicts. Furthermore, the absence of a unified and centralized legislature makes the general principles of lex superior and lex posterior less effective.Footnote ¹⁵ Consequently, lex specialis has assumed greater prominence in international law. For example, in 2001, the International Law Commission (ILC) adopted the Articles on the Responsibility of States for Internationally Wrongful Acts, and Article 55 provides that:

In its 1996 advisory opinion on Nuclear Weapons, the International Court of Justice (ICJ) affirmed that the right not to be arbitrarily deprived of one’s life remains applicable during wartime, noting that “the test of what is an arbitrary deprivation of life … falls to be determined by the applicable lex specialis.”Footnote ¹⁷ Then, in its 2004 advisory opinion on The Wall, the ICJ observed that certain rights may fall under both International Humanitarian Law (IHL) and International Human Rights Law (IHRL), stating that “the Court will have to take into consideration both these branches of international law, namely human rights law and, as lex specialis, international humanitarian law.”Footnote ¹⁸ Following these landmark pronouncements, lex specialis became widely recognized among the international law community. In 2006, the ILC described lex specialis as a generally accepted technique of interpretation and conflict resolution in international law.Footnote ¹⁹ The ILC noted that law may address the relationship between a special rule and a general rule in two ways: first, the special rule may be regarded as an application of the general rule in a given circumstance; second, the special rule may be considered as a modification, an overruling, or a setting aside of the general rule.Footnote ²⁰

II. Within the Constitutional Realm: The Recognition of Lex Specialis

Although the constitutional instrument should be read as a coherent whole, potential inconsistencies among its provisions may nevertheless arise. Therefore, the principle of lex specialis has a legitimate role to play within constitutional jurisprudence.

Article 2(1) of the Basic Law for the Federal Republic of Germany provides for the general freedom of action.Footnote ²¹ The German Federal Constitutional Court held in Elfes that:

In Right of Possession of the Tenant, the Constitutional Court emphasized that Article 2(1) of the Basic Law can only be considered if the scope of protection of another, more specific fundamental right is not affected.Footnote ²³ In Healers, the Constitutional Court ruled that compared to Article 2(1) of the Basic Law, freedom of religion is lex specialis, thus

Article 10 of the European Convention on Human Rights (ECHR) protects the right to freedom of expression, while Article 11 safeguards the right to freedom of peaceful assembly and association.Footnote ²⁵ In Ezelin v. France, the European Court of Human Rights (ECtHR) determined that Article 10 is to be regarded as a lex generalis in relation to Article 11, a lex specialis, so it is unnecessary to consider it separately.Footnote ²⁶ Article 5(4) of the ECHR establishes the right to a speedy review of the lawfulness of detention for individuals deprived of their liberty, whereas Article 6(1) guarantees the right to a fair trial for those facing criminal charges. Article 13 enshrines the right to an effective remedy before national authorities.Footnote ²⁷ In Brannigan and McBride v. The United Kingdom, the ECtHR clarified that the requirements of Article 13 are less strict than those of Article 5(4), which must be regarded as the lex specialis in respect of complaints under Article 5.Footnote ²⁸ In Vasilescu v. Romania, the ECtHR held that Article 6(1) operates as a lex specialis in relation to Article 13, with the requirements of Article 13 being absorbed by those of Article 6(1).Footnote ²⁹

Section 2(e) of the Constitution of Trinidad and Tobago 1962 provides that no Act of Parliament shall deprive a person of the right to a fair hearing. Section 6(1) further stipulates that any person who alleges a violation of his constitutional rights may apply to the High Court for redress. Meanwhile, section 102(4) stipulates that the functions and proceedings of the Police Service Commission shall not be subject to inquiry by any court.Footnote ³⁰ Endell Thomas, a police officer, was dismissed by the Police Service Commission for breaching the Police Service Commission Regulations. He subsequently instituted proceedings in the High Court, arguing that his dismissal was unconstitutional because the Regulations under which he was dismissed were ultra vires.Footnote ³¹ The Attorney General contended that section 102(4) precluded judicial review of the Commission’s actions. However, the Judicial Committee of the Privy Council ruled that if the Commission had done something that lay outside its functions, section 102(4) would not oust the jurisdiction of the High Court to declare that what it had purported to do was null and void. The provision in section 102(4) is qualified by the rights enshrined in sections 2(e) and 6(1). The Privy Council emphasized that “Generalia specialibus non derogant is a principle applicable to constitutional interpretation” and accordingly held that the general “no certiorari” clause in section 102(4) does not override the special right of redress under section 6.Footnote ³²

Article 31 of the Constitution of the People’s Republic of China provides that

According to Qiao Xiaoyang, former director of the Committee for the Hong Kong Basic Law, this provision constitutes a lex specialis, which requires that laws enacted by the National People’s Congress under Article 31, namely the basic laws, shall govern in the special administrative regions.Footnote ³⁴

III. Dissecting the Principle: Three Conceptions of Lex Specialis

Although lex specialis is widely recognized and commonly applied in international law, it has been criticized for its conceptual vagueness.Footnote ³⁵ International legal scholars have generally attributed three distinct meanings to this principle.Footnote ³⁶

In the first sense, lex specialis means total displacement, whereby a specific body of law, as lex specialis, applies to the exclusion of a more general body of law, as lex generalis. For example, it has been argued that during armed conflicts, IHL functions as lex specialis, while IHRL serves as lex generalis; accordingly, IHL should fully displace and render inapplicable IHRL.Footnote ³⁷ However, this interpretation has been increasingly rejected since the end of the Second World War. In its 2011 Report, the ILC emphasized that

More recently, in Georgia v Russia (II), the ECtHR rejected the submission that IHRL is entirely superseded by IHL during armed conflicts.Footnote ³⁹ To date, only a limited number of scholars uphold the total displacement approach.Footnote ⁴⁰

In the second sense, lex specialis refers to partial displacement, whereby a specific provision, as lex specialis, supersedes or qualifies a more general provision, as lex generalis. For example, it is widely acknowledged that IHL and IHRL are complementary during armed conflicts.Footnote ⁴¹ Nevertheless, in certain circumstances, a specific rule under IHL may appear to conflict with a specific rule under IHRL. Where such a conflict is unavoidable, the lex specialis principle permits the IHL rule, as lex specialis, to displace or modify the application of the IHRL rule, as lex generalis, to the extent strictly necessary to resolve the inconsistency.Footnote ⁴² In this context, the principle functions as a tool for resolving norm conflicts. This represents the most widely accepted understanding of “special law prevails over general law.”

In the third sense, lex specialis is regarded as an interpretive tool aimed at avoiding norm conflicts; that is, when interpreting a legal provision, it is essential to consider its relevant provisions to prevent inconsistent or contradictory interpretations.Footnote ⁴³ For instance, a rule of IHL concerning lawful killing may inform the interpretation of a corresponding IHRL on arbitrary deprivation of life. Under this approach, there is no hierarchical relationship between lex specialis and lex generalis; rather, the former functions as a contextual factor in interpreting the latter. In other words, lex specialis does not displace or override lex generalis but assists the interpretation of lex generalis. Some scholars maintain that, in this context, lex specialis constitutes a form of harmonious or systematic interpretation.Footnote ⁴⁴

I. MK: Exploration by CFI

Article 37 of the Basic Law (BL) provides that “the freedom of marriage of Hong Kong residents and their right to raise a family freely shall be protected by law.”Footnote ⁴⁸ Meanwhile, Article 19(2) of the Bill of Rights (BOR)Footnote ⁴⁹ provides that “the right of men and women of marriageable age to marry and to found a family shall be recognized.” MK, a female Hong Kong permanent resident, seeks to marry or enter into a civil union with her same-sex partner. However, same-sex marriages and civil partnerships are not recognized under Hong Kong law.Footnote ⁵⁰ MK initiated judicial review proceedings, arguing that the absence of legal recognition for same-sex unions infringes upon her rights guaranteed under the BL and the BOR, including the freedom of marriage, the right to equality, the right to privacy, and freedom of conscience.Footnote ⁵¹

To address MK’s claims, the court must consider two key questions. First, does freedom of marriage under BL37 extend to same-sex couples? Second, if BL37 does not include same-sex marriage, can MK derive such a right from other fundamental rights protected under the BL and the BOR, including the rights to equality, privacy, and freedom of conscience?

In response to the first question, the CFI answers in the negative. The court holds that the expression “marriage” in BL37 refers exclusively to heterosexual marriage, based on the following three reasons. First, at the time of promulgation of the BL in 1990 and the time that the BL came into effect in 1997, Hong Kong law did not provide for or recognize same-sex marriage. This context is essential for a proper understanding of the BL. Second, at the time of promulgation and implementation of the BL, no country in the world provided for or recognized same-sex marriage. Therefore, it would be unreasonable to assume that the drafters of the BL intended the word “marriage” in Article 37 to include same-sex marriage. Third, BOR19(2) defines marriage as between opposite sexes. BL37 and BOR19(2) should be read consistently with one another.Footnote ⁵²

In response to the second question, the CFI also answers in the negative. The main reason is that BL37 is a special provision which deals specifically with the marriage right of Hong Kong residents. Citing Endell Thomas and other authoritative precedents, the court emphasizes that

This is the first time that a Hong Kong court has applied the lex specialis principle in fundamental rights adjudication. However, scholars have criticized this approach, arguing that the insistence on freezing the meaning of marriage in BL37 as it was understood in the 1990s underpins a problematic sidelining of relevant twenty-first century local and global developments through the lex specialis argument.Footnote ⁵⁴

II. Kwok Cheuk Kin: Confirmation by CFA

Article 40 of the Basic Law provides that “the lawful traditional rights and interests of the indigenous inhabitants of the ‘New Territories’ shall be protected by the Hong Kong Special Administrative Region.”Footnote ⁵⁵ Under the Small House Policy, a male indigenous inhabitant of the “New Territories” who is aged 18 or above may apply, once in his lifetime, for permission to build a small house in his own village.Footnote ⁵⁶ Kwok Cheuk Kin, a non-indigenous resident, contends that the policy constitutes discrimination on the grounds of sex and social origin, and argues that it is invalidated by the anti–discrimination provisions of the BL and the BOR.Footnote ⁵⁷

To address Mr. Kwok’s claims, the Court must consider two principal questions. First, does the right to apply for a small house grant under the Small House Policy, the so-called “Ding rights,” constitute a lawful traditional right or interest protected under BL40? Second, how should the Court deal with the relationship between BL40 and the anti-discrimination provisions of the BL and BOR?

In response to the first question, the CFA answers in the affirmative. The Court points out that BL40 aims to protect rights and interests of the indigenous inhabitants of the New Territories which are (i) special to those inhabitants and not common to the generality of residents, and (ii) potentially open to challenge in the absence of a protective provision like BL40. One obvious basis for such a challenge was the anti-discrimination provisions.Footnote ⁵⁸ Consequently, “lawful” in BL40 is not intended to refer to the absence of discrimination forbidden by the BL and BOR. Likewise, “traditional” in BL40 does not require a protected right or interest to be traceable to the period before 1898.Footnote ⁵⁹ Therefore, even though the Small House Policy was formally introduced in 1972, the benefits it confers qualify as lawful traditional rights and interests protected under BL40.

In response to the second question, the CFA holds that BL40 qualifies and limits the application of the anti-discrimination provisions, not the other way around.Footnote ⁶⁰ The CFA provides four principal reasons in support of this approach. First, the BL is founded on the principle of continuity. Article 40 is a saving provision seeking to give effect to that principle by protecting an existing entitlement of a particular class of persons. Second, it is a principle of statutory construction that the specific prevails over the general. While the anti-discrimination provisions are general, BL40 is a specific provision dealing with the special position of the indigenous inhabitants of the New Territories. Third, if consistency with the anti-discrimination provisions were a condition of being protected by BL40, then either (i) the discrimination is justified, in which case BL40 is unnecessary; or (ii) it is unjustified, in which case BL40 applies to nothing. Fourth, BL122 assumes that grants will continue to be made under the Small House Policy to descendants in the male line of pre-1898 village residents. This assumption strongly indicates the drafters’ intent that BL40 was meant to preserve such rights.Footnote ⁶¹ Therefore, the CFA concludes that the policy should be maintained notwithstanding its discriminatory effects. This is the first time that the CFA has applied the lex specialis principle to address the conflict between constitutionally protected rights. Prior to this ruling, Chow J of the CFI had also referred to the principle that the general does not detract from the specific.Footnote ⁶²

III. Sham Tsz Kit: Expansion and Formalist Reinforcement

Sham Tsz Kit, a permanent resident of Hong Kong, is a homosexual man who entered into a same-sex marriage with his partner in New York in 2013. That marriage is not legally recognized in Hong Kong. Mr. Sham contends that this state of affairs constitutes discrimination and a violation of his constitutional rights to equality and to protection against interference with his right to privacy and family. Following unsuccessful proceedings in the CFI and the Court of Appeal (CA), Mr. Sham appealed the matter to the CFA.Footnote ⁶³

To address Mr. Sham’s claims, the Court must consider three questions. First, does the non-recognition of same-sex marriage infringe upon his right to equality under BL25 and BOR22? Second, does the absence of alternative means of legal recognition of same-sex partnership violate his right to privacy under BOR14Footnote ⁶⁴ and right to equality under BL25 and BOR22? Third, does the non-recognition of foreign same-sex marriage violate his right to equality under BL25 and BOR22?

On the first and third questions, the five justicesFootnote ⁶⁵ are unanimous in holding that the non-recognition of same-sex marriage, including same-sex marriage contracted abroad, does not violate the right to equality.Footnote ⁶⁶ Permanent Judges Ribeiro and Fok, delivering the judgment on behalf of the Court, emphasize that although BL37 does not explicitly distinguish between men and women in the context of marriage, it must be interpreted in conjunction with BOR19(2). When read together, these provisions indicate that the constitutional protection of marriage under BL37 is confined to opposite-sex unions and does not extend to same-sex marriage. The judges underscore that the BL and the BOR must be interpreted as a coherent whole, requiring that BL37 be construed consistently with BOR19(2). Furthermore, they observed that at the time the BL was promulgated in April 1990, and when it came into effect in July 1997, same-sex marriage was not provided for or recognized under the law of any country. The first country to do so was the Netherlands in 2001, so there is no realistic basis for concluding that the drafters of the BL intended, through Article 37, to guarantee same-sex marriage in Hong Kong.Footnote ⁶⁷

After determining that BL37 does not extend constitutional protection to same-sex marriage, Permanent Judges Ribeiro and Fok conclude that the right to equality under BL25 and BOR22 cannot be relied upon to widen the constitutional right to marry to same-sex couples.Footnote ⁶⁸ They emphasize that:

They observe that the lex specialis principle has been consistently recognized and applied by the Court itself, the ECtHR, the Human Rights Committee (HRC), and the Privy Council. In the context of Hong Kong constitutional law, they hold that BL37, read together with BOR19(2), is the lex specialis in relation to the right to marry. As such, the lex specialis confines that constitutional right to opposite-sex marriage and restricts the rights to opposite-sex marriage to the exclusion of same-sex marriage. Therefore, it is not permissible to interpret the right to equality as conferring a constitutional right to same-sex marriage on the grounds either of marriage equality or of recognition of foreign same-sex marriage.Footnote ⁷⁰

On the second question, the five justices are divided. Chief Justice Cheung holds that the right to privacy under BOR14 is focused on non-interference, and because non-recognition does not amount to such interference, there is no infringement on the right to privacy.Footnote ⁷¹ Meanwhile, Permanent Judges Ribeiro and Fok consider that the right to privacy under BOR14 and the right to private life under ECHR8 are indistinguishable; both provisions guarantee substantive privacy rights, and the absence of a legal framework for recognition of same-sex relationships constitutes a hindrance of, or an interference with, the rights under BOR14, whereby they are infringed.Footnote ⁷² Permanent Judge Lam concurs in part with Chief Justice Cheung and in part with Permanent Judges Ribeiro and Fok.Footnote ⁷³ Non-Permanent Judge Keane concurs with Permanent Judges Ribeiro and Fok.Footnote ⁷⁴ The Government contends that requiring legal recognition of same-sex partnerships is equivalent to mandating legal recognition of same–sex marriage, and therefore asserts that the principle of lex specialis precludes same-sex couples from acquiring a right to marry by reliance on the more general privacy provisions.Footnote ⁷⁵ However, Permanent Judges Ribeiro and Fok note that Mr. Sham did not request that alternative forms of legal recognition confer the same rights as those afforded to married couples; rather, he merely complained about the absence of any formal legal recognition for same-sex partnerships.Footnote ⁷⁶ In essence, Mr. Sham’s case does not involve claiming the right to marriage by another name and there is no room for application of the lex specialis doctrine.Footnote ⁷⁷

The CFA’s decision in Sham Tsz Kit has attracted criticism. Scholars consider that the Court’s originalist interpretation of BL37 diverges from its established jurisprudence of treating the Basic Law as a “living instrument.” Moreover, the Court’s reliance on comparative jurisprudence has been characterized as selective, as it fails to address supranational jurisprudence that differs from that of the ECtHR and HRC, particularly the Inter-American Court of Human Rights’ affirmative position on same-sex marriage.Footnote ⁷⁸ More recently, the CFA’s reliance on lex specialis has itself been questioned, with one commentator advocating a proportionality-based approach instead.Footnote ⁷⁹

IV. Nick Infinger and Li Yik Ho: Qualification and Refinement

Article 36 of the Basic Law provides that “Hong Kong residents shall have the right to social welfare in accordance with law.” In Kong Yunming, the CFA held that BL36, read with BL145, constitutionally protects the pre-1997 social welfare system, and any subsequent amendments remain subject to constitutional review.Footnote ⁸⁰ The Hong Kong Housing Authority (HA) is a statutory body tasked with carrying out significant governmental functions related to public housing.Footnote ⁸¹ Under HA policy, individuals in specified familial relationships, such as “husband and wife,” “parent and child,” or “grandparent and grandchild” or “siblings,” may apply for Public Rental Housing (PRH) under the sub-category of “ordinary families.” However, the marital relationship of same-sex couples married overseas is not recognized.Footnote ⁸² Mr. Nick Infinger married his husband in Canada in 2018. With his same-sex spouse as his only family member, he applied for a shared PRH unit under the “ordinary families” sub-category. Pursuant to its policy, the HA rejected the application. Mr. Infinger initiated judicial review proceedings to challenge the policy on the ground of discrimination against same-sex married couples. The HA was unsuccessful in both the CFI and the CA and has now appealed the decision to the CFA.Footnote ⁸³

The HA submits that this case does not engage the right to equality under BL25 or BOR22. Instead, the matter falls squarely within the scope of BL36. Specifically, the HA maintains that BL36 constitutionally entrenches all social welfare benefits and entitlements that existed prior to 1997. Under the pre–1997 social welfare framework, opposite-sex married couples have always enjoyed exclusive rights to apply for PRH. The current HA policy reflects and upholds these constitutionally protected entitlements.Footnote ⁸⁴ BL36 is the lex specialis concerning social welfare rights and policies, just like BL40 is a lex specialis on the lawful traditional rights and interests of indigenous inhabitants of the New Territories. When the BL and the BOR are construed as a coherent whole, it becomes apparent that, much like the rights and interests protected under BL40 are not subject to the general equality provisions, the entrenched social welfare rights under BL36 are likewise excluded from such review.Footnote ⁸⁵

To address the HA’s claims, the CFA must consider three principal questions. First, does this case engage BL36? Second, does BL36 override the equality provisions? Third, are same-sex couples married overseas comparable to heterosexual married couples?Footnote ⁸⁶

In response to the first question, the CFA answers in the negative. Although allowing same-sex married couples to apply does not deprive opposite-sex couples of their rights to apply, the HA submits that this would lengthen the queue and the average waiting time, thereby diluting opposite-sex couples’ pre-existing rights to apply. The CFA observes that this argument might carry weight if a separate queue had been established exclusively for opposite-sex married couples. However, in reality, there is no separate queue for opposite-sex married couples. Opposite-sex married couples, parents and children, grandparents and grandchildren, and single siblings all wait in the same queue. In other words, the entitlement of opposite-sex married couples to apply under the “ordinary families” sub-category is not “exclusive.” Because it is not exclusive, there can be no complaint of dilution. Furthermore, there is no constitutional guarantee on the average waiting time. As such, BL36 is not engaged at all.Footnote ⁸⁷

In response to the second question, the CFA also answers in the negative. The Court notes that social welfare entitlements and benefits under BL36 are concerned with the limited societal resources, and such allocation necessarily involves differentiating amongst members of society. However, such differentiation must be based on criteria that are fair, rational, and otherwise justifiable. The Court underscores that BL36 is fundamentally different from BL40. From the outset, the drafters of the BL were fully aware of the “inherently discriminatory” nature of the “Ding rights” of male indigenous inhabitants of the New Territories. The drafting material and background of the BL demonstrated that its drafters exceptionally intended to accord favorable differential treatment to the male indigenous inhabitants of the New Territories. Consequently, BL40 constitutes a lex specialis and overrides the general equality provisions. In contrast, nothing in the drafting history of BL36 suggests that there was any drafting intention to entrench any social welfare entitlements that were known or suspected to be discriminatory in nature. Therefore, BL36 does not insulate pre-existing social welfare rights from the oversight of the equality provisions.Footnote ⁸⁸ Similarly, BL37 operates as a lex specialis only with respect to the right to marry and does not remove the subject HA policies from the purview of the equality provisions.Footnote ⁸⁹

In response to the third question, the CFA answers in the affirmative. The HA argues that opposite-sex married couples are not true comparators of same–sex ones in the present context because only the former, as a category, have “reproductive capacities and procreative potential” that align with the governmental objective of promoting population growth. The CFA expresses skepticism toward this argument, noting that the HA’s eligibility criteria for housing applications do not distinguish among heterosexual married couples based on whether they have children, intend to have children, are beyond child-bearing age, or are medically or otherwise unable to reproduce. Moreover, opposite-sex married couples are included in the same sub–category of “ordinary families” alongside parents and children, grandparents and children, and single siblings. Procreative potential is irrelevant to these other eligible familial relationships, all of which nonetheless join the same queue as opposite-sex married couples. The CFA observes that the only common thread to these different relationships is a close familial relationship that is in need of housing assistance, and a same-sex married relationship with housing needs fits easily into that description.Footnote ⁹⁰ In other words, same–sex couples who are lawfully married overseas are in an analogous and comparable position to opposite-sex married couples. The HA’s exclusion of such couples from equivalent consideration lacks sufficient justification and constitutes unlawful discrimination.Footnote ⁹¹

Hong Kong law protects the inheritance rights of the surviving spouse but confines “valid marriage” to heterosexual marriage.Footnote ⁹² Mr. Ng Hon Lam, subsequently substituted by his same-sex spouse Mr. Li Yik Ho, argued that this constitutes unlawful discrimination and initiated judicial review proceedings. The Secretary for Justice (SJ) was unsuccessful in both the CFI and CA and has now appealed the decision to the CFA.Footnote ⁹³ The SJ maintains that same-sex marriage is distinct from marriage. Specifically, he contends that the constitutional right to marry under BL37 is restricted to only heterosexual marriage; as lex specialis governing the right to marry, BL37 confers a special status incompatible with the conferment of equivalent rights on same-sex couples. However, the CFA observes that the SJ’s argument is circular, as it relies on the very ground for that differential treatment as its justification. With regard to inheritance rights, the Court finds that married same-sex couples are analogous to married opposite-sex couples; this does not entail recognition of the same-sex couple as having the same status as that of being married under Hong Kong law.Footnote ⁹⁴ The Court further holds that the ruling in Sham Tsz Kit does not assist the SJ on the issue of comparability. Sham Tsz Kit concerned a constitutional right to marry, and Article 37 was the lex specialis in the BL that limited that right only to heterosexual couples. By contrast, the claim in the present case is not one seeking to achieve the status of marriage for a same-sex couple.Footnote ⁹⁵

The CFA’s decisions indicate that the determination of whether a provision constitutes lex specialis or lex generalis is inherently context dependent. A provision deemed lex specialis in one context may be treated as lex generalis in another, depending on the applicable legal framework and factual circumstances. This clarification is both timely and essential: to treat the right to equality abstractly as lex generalis risks rendering it vulnerable to being overridden by less protective provisions.

I. Revisiting Kwok Cheuk Kin: A Justifiable Application

The Kwok Cheuk Kin case involved a conflict between two fundamental rights enshrined in three constitutional provisions. BL40 protects the lawful traditional rights and interests of the indigenous inhabitants of the New Territories, whereas BL25 and BOR25 prohibit discrimination. In resolving this tension, the CFA determined that BL40 constitutes the lex specialis and thus prevails over the general anti-discrimination provisions. This approach is supported by two key considerations. First, the drafting history of BL40 indicates that the framers of the BL were fully aware of the discriminatory nature of “Ding rights” and nonetheless intended to preserve them through this saving provision. Second, according priority to the anti-discrimination provisions would render BL40 effectively meaningless, which contradicts the clear legislative intent that this provision should have substantive legal effect.

As the Court observed, a critical precondition for a specific provision to prevail over a general provision is that the two must be mutually exclusive:

There appears to be no viable solution to reconcile the conflict between the traditional rights and interests of the indigenous inhabitants of the New Territories, particularly “Ding rights,” and the right to equality. Abolishing these discriminatory rights would effectively invalidate BL40, while extending such rights to female indigenous inhabitants and non-indigenous residents is impractical given Hong Kong’s severe land constraints.Footnote ⁹⁸ Consequently, the only feasible approach to preserving the legal effect of BL40 is to accord it precedence over anti-discrimination provisions.

When faced with a similar case, the Canadian Supreme Court has reached the same conclusion. Section 23 of the Canadian Charter of Rights and Freedoms guarantees that eligible Canadian parents belonging to a province’s English or French linguistic minority have the right to have their children receive primary and secondary education in that minority language.Footnote ⁹⁹ Meanwhile, section 73 of the Charter of the French Language provides access to English language schools in Quebec only to children who have received or are receiving English language instruction in Canada or whose parents studied in English in Canada at the primary level.Footnote ¹⁰⁰ The appellant parents, who do not qualify as rights holders under such provisions, claimed that section 73 discriminates between children who qualify and the majority of French–speaking Quebec children who do not, and argued that it violates the right to equality. After unsuccessful proceedings in the Superior Court and the Court of Appeal, the appellants appealed to the Supreme Court of Canada. The Court dismissed the appeal, holding that:

II. Revisiting Sham Tsz Kit: A Case of Misapplication

The Sham Tsz Kit case involved an inconsistency between two fundamental rights protected under four constitutional provisions. BL37, read together with BOR19(2), safeguards the right to opposite-sex marriage, whereas BL25 and BOR22 prohibit discrimination on various grounds. In addressing this apparent inconsistency, the CFA held that BL37 constitutes lex specialis and therefore takes precedence over the anti-discrimination provisions. The Court underscored that:

In reaching this conclusion, the CFA relied upon the jurisprudence of the ECtHR, the HRC, and the Privy Council.Footnote ¹⁰³ The following analysis is therefore equally applicable to these authorities.

The fundamental flaw in this approach lies in its failure to recognize that for a specific provision to override a general one, it must be established that the two provisions are mutually exclusive. As scholars have emphasized, the maxim “lex specialis derogat legi generali,” when interpreted strictly and as indicated by the term “derogat,” entails the partial or total disapplication or displacement of general law in favor of special law.Footnote ¹⁰⁴ Karl Larenz explains this clearly:

The Court asserted that the recognition of same-sex marriage would render BL37 and BOR19(2) redundant. This assertion is unpersuasive. First, BL37 protects the freedom of marriage without defining it as exclusively heterosexual. While historical records indicate the drafters did not intend to endorse same-sex marriage, there is no evidence that they explicitly opposed it. Thus, recognition cannot be said to contradict legislative intent. Second, such recognition does not invalidate the existing right to marry; rather, it expands the scope of that right should BL37 be interpreted as not encompassing it. Numerous jurisdictions now recognize same-sex marriage, with no evidence of this recognition diminishing the institution of marriage. The rights to marriage and to equality are not mutually exclusive but inherently compatible. Therefore, applying BL37 to the exclusion of anti–discrimination provisions is legally unconvincing.

As scholarly commentary has observed, in cases where lex specialis is invoked as the more specific norm which supplements the more general norm without contradiction, the lex specialis and the lex generalis simply accumulate. More precisely, a lex specialis supplementing a lex generalis must always be interpreted in the light of the lex generalis, and vice versa.Footnote ¹⁰⁶ The drafting history of the BL provides no indication that BL37, as a lex specialis, conflicts with BL25 and BOR22, as lex generalis. Consequently, the right to marry under BL37 should be understood as operating in conjunction with the right to equality guaranteed under BL25 and BOR22. This cumulative interpretation lends support to the recognition of same-sex marriage. While such recognition undoubtedly entails significant legal and institutional transformation, the doctrine of lex specialis alone does not provide a legally sound basis for resisting this evolution.

III. Beyond Lex Specialis: Most Favorable Standard

Although lex specialis may assist in resolving conflicts between specific and general provisions, its application entails certain difficulties.

One difficulty lies in determining which provision constitutes lex specialis and which constitutes lex generalis. For instance, in the case of Endell Thomas, while the Privy Council has held that the right to a fair trial constitutes lex specialis, others could also argue that the “no certiorari” clause is lex specialis. Similarly, in cases involving both environmental norms and trade norms, some would contend that the trade norms qualify as lex specialis, whereas others could maintain that the environmental norms constitute lex specialis. As scholars observe, when the relationship between norms is ambiguous, the application of the lex specialis principle often depends on political and other considerations; determining whether environmental protection should take precedence over trade norms or vice versa is a highly value-based decision.Footnote ¹⁰⁷ Thus, the doctrine may, in practice, serve as a veil for political preferences.

In the context of Hong Kong, BL37 constitutes lex specialis with respect to the right to marry, while BL25 and BOR22 serve as lex specialis concerning the right to equality. The question of whether same-sex marriage should be recognized pertains not only to the right to marry but also implicates fundamental issues of equality. Similarly, the issue of whether married same–sex couples may apply for public housing, while falling within the domain of social welfare, also raises fundamental questions of equal treatment. In Sham Tsz Kit, the CFA held that the right to marry, as lex specialis, takes precedence over the right to equality, which it regarded as lex generalis, on the basis that the latter has a broader potential scope. Consequently, the Court excluded the application of the general right to equality in favor of the specific provisions governing marriage. However, this reasoning appears unpersuasive.

Another difficulty emerges from the potential conflict between lex specialis and other legal principles. For example, although international legal norms are generally considered equal in hierarchy, certain norms have been recognized as jus cogens, peremptory norms from which no derogation is permitted.Footnote ¹⁰⁸ When a conflict arises between lex specialis and jus cogens, the determination of which norm should prevail becomes legally complex.Footnote ¹⁰⁹ Similarly, while human rights norms are typically regarded as non–hierarchical, some rights are acknowledged as absolute.Footnote ¹¹⁰ In cases of conflict, the lex specialis does not automatically take precedence over the absolute rights. This complexity is illustrated by the case of Ubamaka Edward Wilson v. Secretary for Security and Another.Footnote ¹¹¹

In Hong Kong, while the BOR enumerates various human rights, section 11 of the Bill of Rights Ordinance (BORO) exempts immigration control from the application of the BOR.Footnote ¹¹² It may be argued that section 11 constitutes lex specialis in relation to the rights enumerated in the BOR, and under the principle, could take precedence. However, in Ubamaka, the CFA held that the prohibition against torture and cruel, inhuman, or degrading treatment or punishment under Article 3 of the BOR is an absolute right, and emphasized that:

Due to such difficulties, scholars have advocated for alternative approaches to the lex specialis principle.Footnote ¹¹⁴ In Abella v. Argentina, the Inter-American Commission on Human Rights (IACHR) held that:

In Coard v. United States, the Commission reiterated that:

This approach, known as the “most favorable standard” principle, prioritizes substantive protection over a formalistic application of lex specialis.Footnote ¹¹⁷

This approach may shed light on the interpretive relationship between BL37 and BOR19(2). On the surface, BOR19(2), which confines marriage to unions between persons of opposite sexes, is more specific in scope and narrowly defined, whereas BL37 does not explicitly limit marriage to heterosexual couples and thus appears broader and more general in application. Under the lex specialis principle, BOR19(2) would prevail as the specific provision over the more general BL37. However, the “most favorable standard” doctrine suggests that courts should prioritize constitutional provisions that offer stronger protection for fundamental rights. Applying this doctrine, courts may give effect to BL37, as it provides a higher level of protection for the right to marry. In doing so, courts would align with the established principle of affording fundamental rights and freedoms a generous interpretationFootnote ¹¹⁸, thereby reinforcing their commitment to robust constitutional protection.