Physician-assisted suicide laws in Oregon and Washington require the person's current competency and a prognosis of terminal illness. In The Netherlands voluntariness and unbearable suffering are required for euthanasia. Many people are more concerned about the loss of autonomy and independence in years of severe dementia than about pain and suffering in their last months. To address this concern, people could write advance directives for physician-assisted death in dementia. Should such directives be implemented even though, at the time, the person (...) is no longer competent and would not be either terminally ill or suffering unbearably? We argue that in many cases they should be, and that a sliding scale which considers both autonomy and the capacity for enjoyment provides the best justification for determining when: when written by a previously well-informed and competent person, such a directive gains in authority as the later person's capacities to generate new critical interests and to enjoy life decrease. Such an extension of legalized death assistance is grounded in the same central value of voluntariness that undergirds the current more limited legalization. (shrink)