In this passage Bentham points to the capacity for
suffering as the vital characteristic that gives a being
the right to equal consideration. The capacity for
suffering-or more strictly, for suffering and/or enjoyment
or happiness-is not just another characteristic
like the capacity for language or higher
mathematics. Bentham is not saying that those who
try to mark "the insuperable line" that determines
whether the interests of a being should be considered
happen to have chosen the wrong characteristic.
By saying that we must consider the interests of
all beings with the capacity for suffering or enjoyment
Bentham does not arhitrarily exclude from
consideration any interests at all-as those who
draw the line with reference to the possession of
reason or language do. The capacity for suffering
and enjoyment is a prerequisite for having interests
at all, a condition that must be satisfied hefore we
can speak of interests in a meaningful way. It would
be nonsense to say that it was not in the interests of
a stone to be kicked along the road by a schoolboy.
A stone does not have interests because it cannot
suffer. Nothing that we can do to it could possibly
make any difference to its welfare. The capacity for
suffering and enjoyment is, however, not only necessary,
but also sufficient for us to say that a being
has interests-at an absolute minimum, an interest
in not suffering. A mouse, for example, does have
an interest in not being kicked along the road, because
it will suffer if it is.