A top-down approach:
• This approach is meant to generate a rule
set from one or more specific ethical
• Wallach and Allen start off pessimistic
about the viability of this approach, but
point out that adherence to rules is an
aspect of morality that must still be
The Big Picture Theories (in
• What will be the authors’ questions about
these theories is what the computability
requirements would be for each. This
approach may shed a unique light on the
practice of morality itself.
• Utilitarianism (a subset of consequentialism)
might initially appeal to us because of
Bentham’s focus on calculability.
• James Gips, in 1995, supplied this list of
computational requirements for a
1. A way of describing the situation in the world
2. A way of generating possible actions
3. A means of predicting the situation that would result
if an action were taken given the current situation
4. A method of evaluating a situation in terms of its
goodness or desirability
• How can one assign numbers to something as subjective
• Do we aim for total or average happiness?
• What are the morally relevant features of any given
situation? (People, animals, ecosystems?)
• How far/wide should the calculation of effect go?
• How much time is a moral agent allowed to devote to the
• Note that these are not only problems generated while
thinking about the computability of moral theories, they
are problems that concern peoples’ application of these
moral theories, and they are issues that have not been
widely settled, and not for lack of discussion.
• The authors do a good job of avoiding the
question “how do humans do this?” when
discussing ethical algorithms and behaviors. It
may well be that general human behavior is not
a good model to emulate for ethical systems.
• This raises the question of what standard to hold
ethical systems to. Do we tolerate the same
range of moral failure among these systems?
These are questions that might fit here, but for
the sake of organization are addressed later in
Asimov’s Laws of Robotics
1. A robot may not injure a human being or,
through inaction, allow a human being to come
2. A robot must obey orders given it by human
beings except where such orders would
conflict with the First Law
3. A robot must protect its own existence as long
as such protection does not conflict with the
First or Second Laws.
(Later, a Zeroth law was added: A robot may not
harm humanity, or, by inaction, allow humanity
to come to harm)
Laws of Robotics
• Asimov was really serious about this, and was (I think
foolishly) optimistic about the usefulness of robotic laws
as stated. (Asimov’s short essay on the robotic laws
forthcoming on the Further Resources section)
• This doesn’t fit with consequentialist theories very well
because of its reliance on special duties
• The zeroth law is hopelessly vague for an action-guiding
principle, and the first law alone can generate conflicts.
• There may be a real pressing difficulty with negative
Specific versus Abstract
• Specific rules are very easy to apply, but
have limited usefulness in novel situations.
Still, perhaps part of what ethical systems
require is a few specific rules for specific
circumstances, though these alone would
not be sufficient.
• Abstract rules are more generally useful,
as they allow adaptation, but are
correspondingly difficult to apply.
The Categorical Imperative
• Act only as you could will that your maxim
become universal law.
– A computer would need to appreciate:
• a goal
• a maxim (a behavior-guiding means to the goal)
• an understanding of the implications for achievement of the
goal by making the maxim universal
• Lying, for example, could not be a universal law,
because its goals would be thwarted by its being
universalized. (This provides a problem,
according to critics of Kant.)
Language vagueness and morality
• Our language is full of words that are vague but
that have clear applications and misapplications.
(e.g. ‘baldness’ is a vague concept, but Captain
Picard IS bald, and the members of the band ZZ
Top are not)
• Perhaps by focusing on the clear applications of
moral rules, we might achieve something useful
for the less clear cases.