Abstract
Can interests survive dementia, permanent unconsciousness--even death? If not, what kills them off? Perhaps lack of attention (one could almost say "lack of interest"), if having the interest requires believing that you have it, caring about its object, and in some sense investing in that object. Thus, once you no longer care about the object, the investment--and the interest--is gone. If an interest disappears when you stop caring about its object, will it disappear when you are mentally incompetent and unable to care about it? If so, then it seems such interests cannot survive the onset of incompetence (let alone death).
This issue arises with living wills and other ways to decide the medical care you will receive when you become mentally incapacitated and unable to decide for yourself. Such decisions are made to protect certain kinds of interest. For example, you may want to avoid expensive end-of-life care in order to protect your family's inheritance, thereby protecting your interest in your family's welfare. Or you might have a religious commitment to the sanctity of life, and therefore an interest in keeping your biological life going as long as possible, even when you are permanently unconscious. We use living wills and similar forms of advance medical decision making to protect our such interests when we anticipate being unable to protect those interests by acting autonomously at the time of treatment. If, however, those interests do not survive incompetence, then the moral authority of living wills is severely undermined, for the interests they are meant to protect do not exist.
It will be argued that some interests can survive a permanent loss of mental capacity, for sometimes, as strange as it sounds, you can be disposed to care about a thing even when you will never be conscious again.