If one always ought to act so as to produce the best
possible circumstances, then morality is extremely
demanding. No one could plausibly claim to have met the
requirements of this "simple principle." . . . It would seem
strange to punish those intending to do good by sentencing
them to an impossible task. Also, if the standards of right
conduct are as extreme as they seem, then they will preclude
the personal projects that humans find most fulfilling.

From an analytic perspective, the potential extreme demands
of morality are not a "problem." A theory of morality is no
less valid simply because it asks great sacrifices. In fact,
it is difficult to imagine what kind of constraints could be
put on our ethical projects. Shouldn't we reflect on our
base prejudices, and not allow them to provide boundaries
for our moral reasoning? Thus, it is tempting to simply
dismiss the objections to the simple principle. However, in
Demands of Morality, Liam Murphy takes these objections
seriously for at least two distinct reasons.

First, discussion of the simple principle provides an
excellent vehicle for a discussion of morality in general.
Perhaps, in a way, this is Murphy's attempt at doing
philosophy "from the inside out.". . . Second, Murphy's
starting point tells us about the nature of his project.
Murphy must take seriously the collisions between moral
philosophy and our intuitive sense of right and wrong. He
[must do so] because his work is best interpreted as
intended to forge moral principles from our firm beliefs,
and not to proscribe beliefs given a set of moral principles.

[Murphy] argues from our considered judgments rather than to
them. . . For example, Murphy cites our "simple but firmly
held" beliefs as supporting the potency of the
over-demandingness objection, and nowhere in the work can
one find a source of moral values divorced from human
preferences.

Murphy does not tell us what set of "firm beliefs" we ought
to have. Rather, he speaks to an audience of
well-intentioned but unorganized moral realists, and tries
to give them principles that represent their considered
moral judgments. Murphy starts with this base sense of right
and wrong, but recognizes that it needs to be supplemented
by reason where our intuitions are confused or conflicting.
Perhaps Murphy is looking for the best interpretation of our
convictions, the same way certain legal scholars try to find
the best interpretation of our Constitution.

This approach has disadvantages. Primarily, Murphy's
arguments, even if successful, do not provide the kind of
motivating force for which moral philosophy has
traditionally searched. His work assumes and argues in terms
of an inner sense of morality, and his project seeks to
deepen that sense. Of course, it is quite possible that the
moral viewpoints of humans will not converge, and some
humans have no moral sense at all. Thus, it is very easy for
the moral skeptic to point out a lack of justification and
ignore the entire work.

On the other hand, Murphy's choice of a starting point
avoids many of the problems of moral philosophy. Justifying
the content of moral principles and granting a motivating
force to those principles is an extraordinary task. It would
be unrealistic to expect all discussions of moral philosophy
to derive such justifications. Projects that attempt such a
derivation have value, but they are hard pressed to produce
logical consequences for everyday life. In the end, Murphy's
strategy may have more practical effect than its
first-principle counterparts, which do not seem any more
likely to convince those that would reject Murphy's premises.