The maxim lex specialis derogat legi generali

(5) General principle. The maxim lex specialis derogat legi generali is a generally

accepted technique of interpretation and conflict resolution in international law. It

suggests that whenever two or more norms deal with the same subject matter, priority

should be given to the norm that is more specific. The principle may be applicable in

several contexts: between provisions within a single treaty, between provisions within

two or more treaties, between a treaty and a non-treaty standard, as well as between

two non-treaty standards. 7 The source of the norm (whether treaty, custom or general

7 For application in relation to provisions within a single treaty, see Beagle Channel Arbitration

(Argentina v. Chile) ILR vol. 52 (1979) p. 141, paras. 36, 38 and 39; Case C-96/00,

Rudolf Gabriel, Judgment of 11 July 2002, ECR (2002) I-06367, pp. 6398-6399, paras. 35-36

and p. 6404, para. 59; Brannigan and McBride v. the United Kingdom, Judgment of

28 May 1993, ECHR Series A (1993) No. 258, p. 57, para. 76; De Jong, Baljet and

van den Brink v. the Netherlands, Judgment of 22 May 1984, ECHR Series A (1984) No. 77,

p. 27, para. 60; Murray v. the United Kingdom, Judgment of 28 October 1994, ECHR Series A

(1994) No. 300, p. 37, para. 98 and Nikolova v. Bulgaria, Judgment of 25 March 1999,

ECHR 1999-II, p. 25, para. 69. For application between different instruments, see Mavrommatis

Palestine Concessions case, P.C.I.J. Series A, No. 2 (1924) p. 31. For application between a

treaty and non-treaty standards, INA Corporation v. Government of the Islamic Republic of Iran,

Iran-US C.T.R. vol. 8, 1985-I, p. 378. For application between particular and general custom,

see Case concerning the Right of Passage over Indian Territory (Portugal v. India) (Merits)

A/CN.4/L.702

page 9

principle of law) is not decisive for the determination of the more specific standard.

However, in practice treaties often act as lex specialis by reference to the relevant

customary law and general principles. 8

(6) Contextual appreciation. The relationship between the lex specialis maxim and

other norms of interpretation or conflict solution cannot be determined in a general way.

Which consideration should be predominant - i.e. whether it is the speciality or the time

of emergence of the norm - should be decided contextually.

(7) Rationale of the principle. That special law has priority over general law is

justified by the fact that such special law, being more concrete, often takes better account

of the particular features of the context in which it is to be applied than any applicable

general law. Its application may also often create a more equitable result and it may

often better reflect the intent of the legal subjects.

(8) Functions of lex specialis. Most of international law is dispositive. This means

that special law may be used to apply, clarify, update or modify as well as set aside

general law.

(9) The effect of lex specialis on general law. The application of the special law does

not normally extinguish the relevant general law. 9 That general law will remain valid and

I.C.J. Reports 1960, p. 6 at p. 44. The Court said: “Where therefore the Court finds a practice

clearly established between two States which was accepted by the Parties as governing the

relations between them, the Court must attribute decisive effect to that practice for the purpose

of determining their specific rights and obligations. Such a particular practice must prevail over

any general rules.”

8 In Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States

of America) (Merits) I.C.J. Reports 1986, p. 14 at p. 137, para. 274, the Court said: “In general,

treaty rules being lex specialis, it would not be appropriate that a State should bring a claim

based on a customary-law rule if it has by treaty already provided means for settlement of a such

a claim.”

9 Thus, in the Nicaragua case, ibid. p. 14 at p. 95 para. 179 the Court noted: “It will … be clear

that customary international law continues to exist and to apply, separately from international

treaty law, even where the two categories of law have an identical content.”

A/CN.4/L.702

page 10

applicable and will, in accordance with the principle of harmonization under

conclusion (4) above, continue to give direction for the interpretation and application

of the relevant special law and will become fully applicable in situations not provided

for by the latter. 10

(10) Particular types of general law. Certain types of general law 11 may not, however,

be derogated from by special law. Jus cogens is expressly non-derogable as set out in

conclusions (32), (33), (40) and (41), below. 12 Moreover, there are other considerations

that may provide a reason for concluding that a general law would prevail in which case

the lex specialis presumption may not apply. These include the following:

• Whether such prevalence may be inferred from the form or the nature of the

general law or intent of the parties, wherever applicable;

• Whether the application of the special law might frustrate the purpose of the

general law;

10 In the Legality of the Threat or Use of Nuclear Weapons, Advisory opinion,

I.C.J. Reports 1996, p. 240, para. 25, the Court described the relationship between human

rights law and the laws of armed conflict in the following way: “… the protection of the

International Covenant of Civil and Political Rights does not cease in times of war, except by

operation of Article 4 of the Covenant … The test of what is an arbitrary deprivation of life,

however, then falls to be determined by the applicable lex specialis, namely, the law applicable

in armed conflict which is designed to regulate the conduct of hostilities. Thus whether a

particular loss of life, through the use of a certain weapon in warfare, is to be considered an

arbitrary deprivation of life contrary to Article 6 of the Covenant, can only be decided by

reference to the law applicable in armed conflict and not deduced from the terms of the Covenant

itself”.

11 There is no accepted definition of “general international law”. For the purposes of these

conclusions, however, it is sufficient to define what is “general” by reference to its logical

counterpart, namely what is “special”. In practice, lawyers are usually able to operate this

distinction by reference to the context in which it appears.

12 In the Dispute Concerning Access to Information under Article 9 of the OSPAR Convention,

(Ireland v. United Kingdom) (Final Award, 2 July 2003) ILR vol. 126 (2005) p. 364, para. 84,

the tribunal observed: “[e]ven then, [the OSPAR Convention] must defer to the relevant

jus cogens with which the parties’ lex specialis may be inconsistent.”

A/CN.4/L.702

page 11

• Whether third party beneficiaries may be negatively affected by the special

law; and

• Whether the balance of rights and obligations, established in the general law

would be negatively affected by the special law.