Modern medicine has put a new twist on one of our most fundamental values . . . self-determination. A patient's right to self-determination becomes a poignant and volatile issue in the context of modern life-sustaining technologies. When the benefit of medical treatment is overshadowed by the resulting burdens, treatment may ethically be withdrawn. Patients have the right to make this decision, assuming they still have the capacity to make it. Through advance directives a competent patient can extend his right to consent to or refuse medical treatment indefinitely into the future. Whether...