the Court will use the methods of interpretation stipulated in Articles 31360 and 32361 of the
Vienna Convention to make this interpretation.362
247. In this case, when analyzing the scope of Article 6 of the American Convention, the
Court has found it useful and appropriate to use other international treaties, in addition to
the Convention, to interpret its provisions in keeping with the evolution of the inter-American
system, taking into consideration the corresponding evolution in the different branches of
international law, particularly international human rights law.363
B.1. The evolution of the prohibition of slavery, servitude, forced labor and
practices similar to slavery in international law
248. The universal elimination of the practice of slavery began in the eighteenth century,
when several national courts declared this practice inacceptable. Despite various bilateral
and multilateral initiatives to prohibit slavery in the nineteenth century, the first universal
treaty on the matter was the Slavery Convention signed at Geneva on September 25, 1926,
under the auspices of the League of Nations. The Convention stipulated that:
Article 1
For the purpose of the present Convention, the following definitions are agreed upon:
(1) Slavery is the status or condition of a person over whom any or all of the powers attaching to
the right of ownership are exercised.
Vienna Convention on the Law of Treaties, Article 31. General Rule of Interpretation. 1. A treaty shall be
interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their
context and in the light of its object and purpose.
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2. The context for the purpose of the interpretation of a treaty shall comprise, in addition to the text, including its
preamble and annexes:
(a) any agreement relating to the treaty which was made between all the parties in connection with the conclusion
of the treaty;
(b) any instrument which was made by one or more parties in connection with the conclusion of the treaty and
accepted by the other parties as an instrument related to the treaty.
3. There shall be taken into account, together with the context:
(a) any subsequent agreement between the parties regarding the interpretation of the treaty or the application of
its provisions;
(b) any subsequent practice in the application of the treaty which establishes the agreement of the parties regarding
its interpretation:
(c) any relevant rules of international law applicable in the relations between the parties.
4. A special meaning shall be given to a term if it is established that the parties so intended .
Vienna Convention on the Law of Treaties, Article 32. Supplementary means of interpretation. Recourse may be
had to supplementary means of interpretation, including the preparatory work of the treaty and the circumstances
of its conclusion, in order to confirm the meaning resulting from the application of article 31, or to determine the
meaning when the interpretation according to article 31:
361
(a) leaves the meaning ambiguous or obscure; or
(b) leads to a result which is manifestly absurd or unreasonable.
Entitlement of Legal Entities to hold Rights under the Inter-American System of Human Rights (Interpretation
and scope of Article 1.2, in relation to Articles 1(1), 8, 11.2, 13, 16, 21, 24, 25, 29, 30, 44, 46, and 62(3) of the
American Convention on Human Rights, as well as of Article 8(1)A and B of the Protocol of San Salvador). Advisory
Opinion OC-22/16 of February 26, 2016. Series A No. 22, para. 35.
362
In this regard, the Court has indicated that the corpus juris of international human rights law comprises a series
of international instruments with varied content and juridical effects (treaties, conventions, resolutions and
declarations). Its dynamic evolution has had a positive impact on international law, in affirming and building up the
latter’s faculty for regulating relations between States and the human beings subject to their respective jurisdictions.
This Court, therefore, must adopt the appropriate approach to consider this question in the context of the evolution
of the fundamental rights of the human person in contemporary international law. Cf. The Right to Information on
Consular Assistance within the Framework of the Guarantees of Due Process of Law, para. 115; and Case of the
Ituango Massacres, para. 157.
363
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