> If there really were
> vampires, and there survival really did depend on drinking the blood of
> humans (in such a way that it killed them and there were no alternatives
> like blood banks) then it would be *right* for vampires to attack humans.
> It would also be *right* for humans to defend themselves. Differences in
> nature produce different behaviors that are good for the beings that do
> them. Given that humans have essentially the same nature, such moral
> divergence is unlikely.
Just to make sure I understand you correctly, is the following a
correct interpretation of the above passage?
Even if all humans were identical, it could still be the case that
one human's deepest value is irrelevant to another. For example, if
each is perfectly egoistic, then Mr. X's deepest value might be the
flourishing of Mr X; whereas Mr. Y only cares about Mr. Y etc. The
obvious sense in which you could say that these egosists have a
common moral is that they could produce a set of norms that would
apply to them all, such as "Don't steal! (Because if you do, the
police will get you.)". I presume the point with the vampire example
is to give an example of how there could be creatures with
sufficiently different goals or abilities to make human morality
irrelevant to them.
If this is right then what distinguishes moral knowledge from
other knowledge? Is it just that moral knowledge typically concerns
life strategies or codes for interacting with other humans? Would
"Take out an insurance!" or "Con thy neighbor subtly!" count as a
moral imperative for humans, supposing that it would be good advise
for most people (i.e. that each would better obtain her own values if
she follows it than if she doesn't)?