74 4. Accused persons shall, save in exceptional circumstances, be segregated from convicted persons, and shall be subject to separate treatment appropriate to their status as unconvicted persons. 5. Minors while subject to criminal proceedings shall be separated from adults and brought before specialized tribunals, as speedily as possible, so that they may be treated in accordance with their status as minors. 6. Punishments consisting of deprivation of liberty shall have as an essential aim the reform and social readaptation of the prisoners. 143. There is an international legal system that absolutely forbids all forms of torture, both physical and psychological, and this system is now part of ius cogens.146 Prohibition of torture is complete and non-derogable, even under the most difficult circumstances, such as war, the threat of war, the struggle against terrorism, and any other crimes, state of siege or of emergency, internal disturbances or conflict, suspension of constitutional guarantees, domestic political instability, or other public disasters or emergencies.147 144. This Court has said that “the interpretation of a treaty must take into account not only the agreements and instruments related to the treaty (paragraph 2 of Article 31 of the Vienna Convention), but also the system of which it is part (paragraph 3 of Article 31).” This orientation is especially important for International Human Rights Law, which has moved forward substantially by means of an evolutive interpretation of the international protection instruments.148 145. The Inter-American Convention against Torture, which entered into force in the State on December 9, 1999, is part of the inter-American corpus iuris that this Court must resort to in establishing the content and scope of the general provision contained in Article 5(2) of the American Convention. Special attention must be paid to Article 2 of the Inter-American Convention against Torture, which defines the latter as: […]any act intentionally performed whereby physical or mental pain or suffering is inflicted on a person for purposes of criminal investigation, as a means of intimidation, as personal punishment, as a preventive measure, as a penalty, or for any other purpose. Torture shall also be understood to be the use of methods upon a person intended to obliterate the personality of the victim or to diminish his physical or mental capacities, even if they do not cause physical pain or mental anguish. This same provision adds that: The concept of torture shall not include physical or mental pain or suffering that is inherent in or solely the consequence of lawful measures, provided that they do not include the performance of the acts or use of the methods referred to in this article. 146 See Case of the Gómez Paquiyauri Brothers, supra note 8, para. 112; and Case of Maritza Urrutia, supra note 8, para. 92. 147 See Case of the Gómez Paquiyauri Brothers, supra note 8, para. 111; Case of Maritza Urrutia. supra note 8, para. 89; and Case of Cantoral Benavides, supra note 139, para. 95. 148 See Case of the Gómez Paquiyauri Brothers, supra note 8, para. 165; Case of the “Street Children” (Villagrán Morales et al.), supra note 145, paras. 192 and 193; and The Right to Information on Consular Assistance in the Framework of the Guarantees of the Due Process of Law, supra note 133, para. 113.