Because of the difficulty of establishing general moral principles to which everyone will agree, it is
sometimes tempting to abandon the idea of moral objectivity. The philosopher Jesse Prinz defends
moral relativism, the view that moral judgments are just reflections of cultural values that vary from
one society to another. He describes the large divergence of moral views across individuals and
cultures on issues such as monogamy, homosexuality, and cannibalism, practiced by many peoples.
He thinks that there is nothing more to the rightness or wrongness of an action than emotional attitudes
of approval or disapproval.
Most of the traditional routes to moral objectivity do not work. I have already criticized the
religious route based on faith and the a priori route based on pure reason. Another possibility is that
all humans are born with innate ethical principles that constitute a moral universal grammar. There
are several problems with this suggestion. First, there is little evidence that there are any ethical
principles that are culturally universal. It is not hard to identify cultures whose practices include
murder, cannibalism, infanticide, and incest, so any attempt to root our favorite ethical principles in
universal properties of mind seems implausible. Second, if particular ethical principles are innate, it
should be possible to identify specific brain areas for moral reasoning where the principles are
stored and processed, akin to the dedicated areas in the brain for vision. But the emotional
consciousness model and the rapidly increasing studies involving brain scans of moral reasoning
suggest that many interacting brain areas are involved in moral reasoning, not some localized module.
Third, even if there are principles that are culturally universal and biologically based, they might
not be ethically acceptable. For example, suppose people had an innate xenophobic principle derived
from our evolutionary history that prescribed the inferior treatment of members of groups other than
our own. This principle would be innate but wrong, just as I argued in chapter 2 that innate beliefs
about the world such as Euclidean geometry can be wrong. Like scientific knowledge, moral
judgments should be assumed to be fallible and subject to reevaluation based on accumulating
evidence. Hence I see no reason to believe that there is a moral universal grammar that might provide
some basis for moral objectivity.
Many contemporary philosophers look to the method of reflective equilibrium as providing a route
to objectivity. This method consists of reflectively adjusting our moral intuitions and moral principles
until equilibrium is reached in the form of a rich set of intuitions and principles that fit well with each
other. There are two major problems with reflective equilibrium as a source of moral objectivity.
The first problem is the highly subjective nature of moral intuitions as revealed by the emotional
consciousness account given above. We have little idea why we have the particular emotional
reactions that we do to different situations, because the brain processes described in the EMOCON
model are not accessible to consciousness. Your initial moral intuitions may be based on rich and
valuable personal experiences of what benefits people's lives, but they may also be based on the
unsubstantiated moral prejudices of teachers and caregivers. Many contemporary ethicists like to treat
moral intuitions as evidence, akin to experimental data that are to be explained by theories. But the
method described in chapter of 2 of evaluating theories on the basis of data relied on the general
robustness of the results of observation and experience. Moral intuitions have no similar robustness
and therefore should not be treated as data. There is thus no reason why they should be allowed as
input to the process of reflective equilibrium, even if the consideration of principles can be expected
to lead to the revision of intuitions.
Second, the method of reflective equilibrium is flawed because it is often much too easy to reach
equilibrium without achieving anything like objectivity. Rawls got the equilibrium idea by analogy
with what he thought goes on in logic, where logical principles are supposedly developed that fit with
evolving intuitions about what kinds of inference are legitimate. On this view, logical principles such
as modus ponens (if p then q; p, therefore q) and statistical inference are not true a priori but instead
are arrived at through a process of mutual adjustment with logical intuitions. The problem, however,
is that people can settle into equilibrium states with a good fit of intuitions and principles that
nevertheless are not very logical. Many people subscribe to the gambler's fallacy—for example, if a
tossed coin has turned up heads many times in a row, then tails is due to turn up. In ethics, it has been
historically easy for people to become highly content with principles such as that what the Bible says
about right and wrong is true. Hence reflective equilibrium provides at best a weak method of
pursuing moral objectivity, not any kind of defense of it.
We saw in chapter 4 that evidence based on observation and experiment provides a way of making
the coherence of theory and data more than a purely internal matter. We need a similar way to break
out of the circle of intuitions and principles that the method of reflective equilibrium generates. Vital
needs provide the most attractive direction, because the question of what we need to function
minimally and maximally as human beings is at least partly empirical. Biology tells us that people
cannot live without food and water. For a broader account of successful functioning as a human being,
we need to look to other empirical sources such as psychology, anthropology, and sociology.
If there are objective vital needs that provide the basis for human rights across cultures, then we
have grounds for rejecting Prinz's leap from descriptive relativism (morals vary across cultures) to
normative relativism (morals are subjective). Consider, for example, cannibalism, formerly common
in many cultures. It is easy to see that killing people in order to eat them violates the vital needs of the
victims, although eating people dead of natural causes would be a different matter. Equally obviously,
homosexuality does not violate any human rights in Orend's sense, and discrimination against it is a
threat to elementary equality and personal freedom, as well as to the psychological need for
autonomy. A more difficult case is polygamy, in hypothetical cases where breaking the usual Western
one-to-one correspondence between husbands and wives does not damage the vital interests of
women who are voluntarily involved. In practice, however, polygamy has usually been accompanied
by violations of the rights of women with respect to equality, freedom, and recognition, and
sometimes even personal security.
In sum, moral objectivity becomes possible if we look, not to theology or a priori reasoning, but to
evidence drawn from biology and psychology. Needs-based consequentialism fits well with the
brain-based emotional consciousness account of moral intuition and with the cultural diversity of
moral behavior. The difficulty of arriving at indisputable moral principles is the result not of moral
relativity, but rather of the huge complexity of determining the range and importance of human
psychological needs and calculating the consequences of the available range of actions. Moral
judgments are very difficult decisions, but we can still strive to use all we know about the nature of
the world and human minds to make them the best we can.