A more obvious answer is better. What primarily makes killing
wrong is neither its effect on the murderer nor its effect on the
victim's friends and relatives, but its effect on the victim. The loss of
one's life is one of the greatest losses one can suffer. The loss of one's
life deprives one of all the experiences, activities, projects, and enjoyments
that would otherwise have constituted one's future. Therefore,
killing someone is wrong, primarily because the killing inflicts
(one of) the greatest possible losses on the victim. To describe this as
the loss of life can be misleading, however. The change in my biological
state does not by itself make killing me wrong. The effect of the
loss of my biological life is the loss to me of all those activities,
projects, experiences, and enjoyments which would otherwise have
constituted my future personal life. These activities, projects, experiences,
and enjoyments are either valuable for their own sakes or are
means to something else that is valuable for its own sake. Some parts
of my future are not valued by me now, but will come to be valued by me as I grow older and as my values and capacities change. When I
am killed, I am deprived both of what I now value which would have
been part of my future personal life, but also what I would come to
value. Therefore, when I die, I am deprived of all of the value of my
future. Inflicting this loss on me is ultimately what rnakes killing me
wrong. This being the case, it would seem that what makes killing any
adult human being prima facie seriously wrong is the loss of his or
her future.
The analysis assumes that killing me (or you, reader) is
prima facie seriously wrong.