Rules of medical ethic bid since the times of antiquity to respect the patients dignity. Today to respect the dignity of any man is a general legal rule. In the same way other rules of the traditional medical ethic became legal norms as for instance the command forbidding to do harm to someone. The law intends to limit the possibilities to exercise power. Therefore it does not compete to the doctor alone to decide that a medical treatment has to be applied. The legal base of a medical treatment lies in the consent of the patient who has been duly cleared up on his state, the necessary treatment and its risks. If it has to be decided if a doctor has given the right treatment in a special case it does not suffice to consult the general rules of the law; the circumstances of the case have to be considered as well. The doctor has to decide, according to the actual medical knowledge and the rules of his professional art what the appropriate proceeding is. Legal and medical considerations are closely connected if one judges a doctor handling a special case. If the patient consents, the doctor is not obliged to treat him, but he is entitled to do it, cases of emergency excepted. If and in what way he treats the patient has to be decided by the doctor according to medical criterias. If a patient, sound of mind, who is suffering heavily by an incurable illness asks the doctor to restrain treatment to alleviating the pains and to the absolute cares to preserve life, the doctor is bound by his patient's wish. In analogy the legal construct of "conducting business without mandate" allows the doctor to proceed in the same way if the patient who lost consciousness is not able to decide upon the treatment and whose death is inevitable and imminent if this is the only wise to respect the dignity of the patient.