The Replaceability Argument - Killing Happy Animals: Explorations in Utilitarian Ethics - page 62

created being can be used to compensate for the remaining welfare loss,
then this might in principle hold also for the welfare loss that is caused
by killing a person. It is unclear where the limit should be. Alternatively
if a (little) remaining welfare loss is deemed acceptable, it is unclear how much
loss is supposed to make a being irreplaceable. It seems that those lines have
to be drawn somewhere, and this can only be done in an arbitrary way.
5.5 Singer's account of welfare fails to restrict
replaceability in the desired way
The purpose of Singer's argument is to limit the scope of the Replaceability
Argument. Therefore, it is interesting to point out who would still be
replaceable if one accepted Singer's argument. Even if Singer's account
of welfare were accepted, the Replaceability Argument would still be
rather inclusive.
On Singer's account, only beings that are highly future-oriented are
completely excluded from replaceability. That leaves many animals,
human and non-human, replaceable. Human babies and young children
are usually not highly future-oriented, neither are many non-human
animals. Even great apes, which Singer would otherwise want to count
as 'persons', 27 are not highly future-oriented. Also other mammals, such
as pigs and cows, which are used in animal husbandry and which Singer
wants to give the 'benefit of the doubt' concerning personhood, 28 live
very much by the day. So, the criterion of being highly future-oriented
might well be very strict. All those who are not highly future-oriented
are supposed to be replaceable to a certain degree. So far, at least normal
human adults seem to be excluded.
However, Singer cannot even insist on that. Singer must grab one
of two horns of a dilemma: either a being is replaceable, or it would
be better off having not lived. Remember that in order to avoid the
implication that most of us would be better off having not lived, the
sufficiency level must be put low enough, well beneath the original
'zero'. However, if it is set low enough for that purpose, many people
might reach that level during their lives. So, they would reach a level
where they still have important unsatisfied preferences, but where a
'sufficient' amount of preference satisfaction can be enjoyed. People
who reached that level during their lives would be out of the nega-
tives, and thus be replaceable. Would there be any sufficiency level that
avoided both the implication of being replaceable and the implication
of being better off having not lived? There would be no such level. To
the extent that one implication is avoided, the other is present. Singer
suggests the level 'at which we consider a life ceases to be worth living,