Art. 1, 5 and 8 of the Federal Act on Personal Capacity; cessation of minor guardianship ipso jure upon attainment of majority; adult guardianship only on the statutory grounds and after prior interdiction proceedings. Majority is determined by an objective age threshold and excludes any discretionary review by guardianship authorities as to the ward's maturity or suitability for self-management (consid. 1). A guardianship established solely because of minority cannot subsist beyond majority; if no adult interdiction procedure has been commenced, the continued restriction of legal capacity is unlawful and the estate must be restored to the now-capable person (consid. 2).