Re B (Consent to Treatment: Capacity) 
A mentally competent tetraplegic patient, as a result of catastrophic injuries leaving her unable to breathe without artificial respiration, requests that the life-sustaining artificial respiration be withdrawn. The health authority took this as an indication of lack of mental capacity and refused to disconnect the life support mechanisms.
Judgment: The right of the mentally competent patient to refuse medical treatment even if the result is death (or no reasons at all) should be respected. The patient autonomy of a mentally competent person should be respected. The question of mental capacity was not to be disturbed by the fact that the patient may assert values not approved by those in the authority. Where the doctors found themselves unable to carry out a patient's wishes, it was for the doctors to find a doctor who would. A trespass occurred if there had been treatment against the patient's wishes.
Considerations in the decision (Lord Donaldson MR)
Patient's interest: right to self-determination which means his right to live his own life how he wishes, even if it will damage his health or lead to his premature death.
Society's interest: all human life is sacred and should be preserved if at all possible.
Eventually, it is well established that in the ultimate the right of the individual is paramount.