A/HRC/43/49 and resilience and contextual circumstances. 19 All these elements must be holistically evaluated on a case-by-case basis and in the light of the specific purpose pursued by the treatment or punishment in question. For instance, the threat of overnight detention combined with verbal abuse may be sufficiently severe to coerce or intimidate a child, whereas the same act may have little or no effect on an adult, and even less on a hardened offender. The severity of pain or suffering resulting from a particular type of ill-treatment is not necessarily constant but tends to increase or fluctuate with the duration of exposure and the multiplication of stressors. Also, while torture constitutes an “aggravated” form of cruel, inhuman or degrading treatment or punishment, 20 “aggravation” does not necessarily refer to aggravated pain and suffering, but to aggravated wrong in terms of the intentional and purposeful instrumentalization of pain and suffering for ulterior purposes. Thus, the distinguishing factor between torture and other forms of ill-treatment is not the intensity of the suffering inflicted, but rather the purpose of the conduct, the intention of the perpetrator and the powerlessness of the victim (A/72/178, para. 30; and A/HRC/13/39, para. 60).21 31. Several treaty provisions even suggest that the concept of torture includes conduct which, at least potentially, does not involve any subjectively experienced pain or suffering at all. Thus, article 7 of the International Covenant on Civil and Political Rights expressly prohibits “medical or scientific experimentation without free consent”. Although the provision does not clarify whether such conduct would amount to “torture” or to other “cruel, inhuman or degrading treatment”, its explicit mention suggests that it was regarded as a particularly grave violation of the prohibition. Even more explicit in this respect, but only of regional applicability, is article 2 of the Inter-American Convention to Prevent and Punish Torture, which expressly defines “torture” as including “methods 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”. Relatedly, upon ratification of the Convention against Torture, the United States expressed its understanding that “mental pain or suffering” refers to “prolonged mental harm” caused by, inter alia, the threatened or actual “administration or application of mind-altering substances or other procedures calculated to disrupt profoundly the senses or the personality”, wording intended to ban some of the interrogation methods developed by the United States Central Intelligence Agency (CIA) during the cold war, but also to deliberately narrow the definition established in the Convention.22 Although the Committee rejected this interpretation as too narrow and stated that psychological torture cannot be limited to “prolonged mental harm” (CAT/C/USA/CO/2, para. 13; and CAT/C/USA/CO/3-5, para. 9), it did not clarify whether the use of “procedures calculated to disrupt profoundly the senses or the personality” could amount to torture even in the absence of subjectively experienced pain or suffering. While this was already a salient question for the drafters of the various treaty texts during the cold war era, its practical relevance has increased exponentially in present times. 32. Given the rapid advances in medical, pharmaceutical and neurotechnological science, as well as in cybernetics, robotics and artificial intelligence, it is difficult to predict to what extent future techniques and environments of torture, as well as the “human enhancement” of potential victims and perpetrators in terms of their mental and emotional resilience, may allow the subjective experience of pain and suffering to be circumvented, suppressed or otherwise manipulated while still achieving the purposes and the profoundly 19 20 21 22 Inter-American Court of Human Rights, Lysias Fleury and Others v. Haiti, Judgment, 23 November 2011, para. 73. Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment, art. 1. Gerrit Zach, “Definition of torture”, in Manfred Nowak, Moritz Birk and Giuliana Monina, eds., The United Nations Convention against Torture and its Optional Protocols: A Commentary, 2nd ed. (Oxford, United Kingdom of Great Britain and Northern Ireland, Oxford University Press, 2019), p. 47. David Luban and Katherine S. Newell, “Personality disruption as mental torture: the CIA, interrogational abuse, and the U.S. Torture Act”, Georgetown Law Journal, vol. 108, No. 2 (January 2020), pp. 335–336 and 373–374, referring to Title 18 of the United States Code, sect. 2340(2)(B), 2012. 9