56 A. AND OTHERS v. THE UNITED KINGDOM JUDGMENT time he suffered any hardship beyond that inherent in detention, his complaint under Article 3 is manifestly ill-founded within the meaning of Article 35 § 3 of the Convention. Since Article 13 requires the provision of a domestic remedy in respect of “arguable complaints” under the Convention (see, for example, Ramirez Sanchez v. France [GC], no. 59450/00, § 157, ECHR 2006-IX), it follows that the second applicant’s complaint under Article 13 is also manifestly illfounded. Both these complaints by the second applicant must therefore be declared inadmissible. 124. The Court notes the Government’s assertion that there was a remedy available to the applicants under the 1998 Act, which they neglected to use. However, since the applicants complain under Article 13 that the remedies at their disposal in connection with their Article 3 complaints were ineffective, the Court considers that it is necessary to consider the Government’s objection concerning non-exhaustion together with the merits of the complaints under Articles 3 and 13. 125. The Court considers that, save those of the second applicant, the applicants’ complaints under Articles 3 and 13 of the Convention raise complex issues of law and fact, the determination of which should depend on an examination of the merits. It concludes, therefore, that this part of the application is not manifestly ill-founded within the meaning of Article 35 § 3 of the Convention. No other ground of inadmissibility has been raised and it must be declared admissible. 2. The merits (a) General principles 126. The Court is acutely conscious of the difficulties faced by States in protecting their populations from terrorist violence. This makes it all the more important to stress that Article 3 enshrines one of the most fundamental values of democratic societies. Unlike most of the substantive clauses of the Convention and of Protocols Nos. 1 and 4, Article 3 makes no provision for exceptions and no derogation from it is permissible under Article 15 § 2 notwithstanding the existence of a public emergency threatening the life of the nation. Even in the most difficult of circumstances, such as the fight against terrorism, and irrespective of the conduct of the person concerned, the Convention prohibits in absolute terms torture and inhuman or degrading treatment and punishment (see Ramirez Sanchez, cited above, §§ 115-16). 127. Ill-treatment must attain a minimum level of severity if it is to fall within the scope of Article 3. The assessment of this minimum depends on all the circumstances of the case, such as the duration of the treatment, its physical or mental effects and, in some cases, the sex, age and state of