...unlawful but not determinative of it. The lawfulness of the detention is, he submits, dependent on the well known principles set out in Re Hardial Singh [1984...Hardial Singh principles, taking into account all the relevant factors, including the Secretary of State's policy, not only with regard to people with mental health problems but in all other relevant...authorities under two main headings. In the first category of authorities, he considered Hardial Singh itself and the restatement of the Hardial Singh principles in R(I) v Secretary...