This paper revisits Ronald Dworkin’s influential position that a person’s advance directive for future health care and medical treatment retains its moral authority beyond the onset of dementia, even when respecting this authority involves foreshortening the life of someone who is happy and content and who no longer remembers or identifies with instructions included within the advance directive. The analysis distils a eudaimonist perspective from Dworkin’s argument and traces variations of this perspective in further arguments for the moral authority of advance directives by other authors. It then critiques a feature of the eudaimonist perspectives within these arguments—namely, the position that dementia has a retroactive negative impact on what a person has previously valued—and challenges the commonly held assumption underlying them that a person’s life and well-being have relatively low value beyond the onset of dementia. Although advance directives have moral authority as a means of guiding one’s future health care, accounts that dismiss the value of the lives and well-being of people living with dementia should be questioned to the extent that such accounts are used to support the moral authority of advance directives stipulating measures to foreshorten individuals’ lives.

本文重新审视了罗纳德·德沃金（Ronald Dworkin）的颇具影响力的观点，即一个人对未来医疗保健和医疗的预先指示在痴呆症发作后仍保留其道德权威，即使尊重这种权威涉及缩短一个快乐、满足且不再记得的人的生命或与预设医疗指示中包含的说明进行标识。该分析从德沃金的论点中提炼出一种幸福主义的观点，并在其他作者关于预先指示的道德权威的进一步论证中追踪了这种观点的变化。然后，它批评了这些论点中幸福主义观点的一个特征，即痴呆症对一个人以前的价值观具有追溯性负面影响的立场，并挑战了人们普遍持有的假设，即一个人的生活和福祉相对痴呆症发作后的价值较低。尽管预先指示作为指导个人未来医疗保健的一种手段具有道德权威，但忽视痴呆症患者的生命和福祉的说法应该受到质疑，因为这些说法被用来支持痴呆症患者的道德权威。预先指示规定了缩短个人寿命的措施。