In Cruzan v. Director, Mo. Dept. of Health, 497 U.S. 261 (1990), the Court considered whether Nancy Beth Cruzan, who had been severely injured in an automobile accident and was in a persistive vegetative state, "had a right under the United States Constitution which would require the hospital to withdraw life-sustaining treatment" at her parents' request. 497 U.S., at 269. The Court began with the observation that "at common law, even the touching of one person by another without consent and without legal justification was a battery." Ibid. The Court then discussed the related rule that "informed consent is generally required for medical treatment." Ibid. After reviewing a long line of relevant state cases, we concluded that "the common-law doctrine of informed consent is viewed as generally encompassing the right of a competent individual to refuse medical treatment." Id., at 277. Next, we reviewed our own cases on the subject, and stated that "the principle that a competent person has a constitutionally protected liberty interest in refusing unwanted medical treatment may be inferred from our prior decisions." Id., at 278. Therefore, "for purposes of that case, we assumed that the United States Constitution would grant a competent person a constitutionally protected right to refuse life saving hydration and nutrition." Id., at 279; see id., at 287 (O'Connor, J., concurring). The Court concluded that, notwithstanding this right, the Constitution permitted Missouri to require clear and convincing evidence of an incompetent patient's wishes concerning the withdrawal of life-sustaining treatment. Id., at 280-281. In Cruzan v. Director, Missouri Department of Health, 497 U.S. 261, 281, 110 S.Ct. 2841, 111 L.Ed.2d 224 (1990), the Supreme Court held that a state could constitutionally condition the withholding of life-sustaining treatment of an incompetent patient on whether or not the patient, when competent, had manifested a clear and convincing intention that such treatment be withheld. Cruzan, 497 U.S. at 284, 110 S.Ct. 2841. Indeed, if the patient's intention had never been made clear, "a State may properly decline to make judgments about the `quality' of life that a particular individual may enjoy, and simply assert an unqualified interest in the preservation of human life." Id. at 281-82, 110 S.Ct. 2841. As a corollary, where a patient's intention is unclear or non-existent, a state may properly disregard the wishes of a patient's family simply because "there is no automatic assurance the view of close family members would necessarily be the same as the patient's would have been had she been confronted with the prospect while competent." Id. at 286, 110 S.Ct. 2841. Furthermore, the Court noted that "we do not think the Due Process Clause requires the State to repose judgment on these matters with anyone but the patient herself." Id.