In medical decision-making contexts, respect for personal autonomy protects the patient from unwanted interventions that some might believe promotes the patient’s overall well-being. When a patient becomes incompetent and loses decision-making capacity, the default judicial approach suggests that, out of a respect for autonomy, surrogate decision-makers should prioritize the treatment preferences that the incompetent patient expressed when he or she was competent. There are, however, several practical and philosophical objections to this approach: there are concerns that the autonomy-based interests that inform a competent patient’s previously expressed preferences cease to be meaningful when the patient can no longer appreciate or value whether or not those interests have been honored. Another concern is that if severely demented and comatose patients are no longer the same persons they once were, then previous treatment preferences given by the prior self may have no moral authority to direct treatment decisions for the now incompetent patient. Both these concerns and more have led to widespread disagreement as to the moral and legal authority of one’s personal autonomy in medical decision-making situations involving incompetent patients. This paper explores the value of autonomy in more detail in an attempt to better understand how to best respect the wishes, preferences, values, goals and the overall well-being of incompetent patients who have lost decision-making capacity.