Quantitative ethics is an interesting combination of humanities and sciences.
humanities aspect is ethics in the philosophical tradition. What is the
right and the wrong thing to do in a given situation? What is good and
what is evil in specific cases? What is just and what is criminal?
What exactly is the difference between virtue and vice?
scientific aspect of quantitative ethics is the use of quantitative
methods - experiments, database analyses, and statistics. All
researchers who insert calculations or tables of figures
into texts on ethical issues can call themselves quantitative
reasoning has proven very successful in the history of philosophy. But
quantitative methods have been equally successful, if not more so. So
it makes sense to combine the two and get the best of both worlds.
Unfortunately, surprisingly few do that.
Human quantiative ethics (HQE)
HQE is quantitative ethics in which the numbers in the tables and
calculations refer to human lives. Consider the following example.
A country is discussing whether to build another nuclear reactor. Many
are afraid of a future meltdown. In a worst-case scenario, a nuclear
accident could cause the deaths of thousands of people plus thousands
of birth defects in future children. The size of the risk depends on
the probability of such a disaster, and there are in general
different possible future scenarios to consider, each
involving different probabilities and different estimated
numbers of deaths. The question can be approached rationally and
carefully by applying principles of risk assessment
and multiplying the probability given scenarios with the number of
deaths in each scenario. Of course the probabilities can only be
estimated quite approximately, but experts generally agree whether a
given probability is 10%, 1%, 0.1% or 0.01%. In this way, one might
estimate the effective number of people that will die per year, on
average, as a result of the reactor's operation. That might then be the
basis for a public discussion about the number of lives one might
reasonably risk in exchange for a reliable source of electricity for
millions of people for a period of decades.
It is possible in such cases that there will be never be a nuclear
accident. The new reactor may never cause a single death or a single
birth defect. That is the outcome that everyone wants, of course, but
at the same time any responsible person will want to be informed of all
possible outcomes and will want these to be systematically considered
before deciding whether or not to go ahead with the project.
Rational quantitative methods based on reasonable assumptions and
estimates can allow us to estimate the probable future human impact of
different global warming scenarios. We can estimate the number of
future people who will probably die (that is, whose lives will probably
be shortened) as an indirect result of the burning of fossil fuels
today (calculator - model).
This is an important contribution to the climate debate that to my
knowledge has been largely ignored or even suppressed. Perhaps
most people are in denial about the human cost of climate change - even
those who are quite clear about climate change itself and its human
causes. Perhaps those in denial about the human costs of climate change
include most climate scientists! The
reader is asked to regard this statement as a scientific hypothesis
rather than a criticism. I am interested in the extent to which such a
claim could be correct. After all, climate scientists are only human
and they have enough to worry about, without in addition considering
how many humans might die in different warming scenarios.
HQE and human rights
HQE is based on human rights. There are two central premises.
first is that a human life is the most valuable thing of all. From a
scientific perspective, this is nonsense. Consider the physical
universe, in which human life is ultimately meaningless. Moreover, no
corner of the universe is objectively speaking any more "valuable" than
any other. In a purely natural-scientific approach it doesn't make much
sense to ascribe "value" to physical things at all. But we humans
are not objective in this regard. On the contrary, our fundamental
assumptions about ethics, and consequently all that is good or
valuable, are ultimately based on the the value of human beings, and
consequently of human lives. Things that are valuable to humans are
ultimately things that bring health and happiness to people.
second premise upon which HQE is based is the idea that all humans are
equal, regardless of cultural background, skin color, language,
religion, gender, sexual orientation, age, (dis-)ability, height,
political convictions and so on. Again, this is a widely accepted
foundation of human rights. But few have considered the quantitative
follows logically from these two premises that two human lives are
twice as valuable as one. Therefore, if two human lives are threatened
we should try twice as hard to save them. So far, so good.
HQE and the psychology of large numbers
But what happens when the numbers get much bigger? Is a catastophe
involving a million deaths a million times worse than an accident in
which one person dies?
We don't perceive a million
lives (or deaths) as a million times more important than one life (or
death), because our ability to empathize is limited. It is almost
beyond us to empathize with just one dying person. First, their
suffering may be greater than any suffering we have experienced
ourselves. Second, there is something about death that we may
never understand. What happens to our consciousness or "soul" after we
die? Humans have been speculating about that for as long as they could
be called humans, and even today we are no closer to a solution -
except that many of us have at least had the courage to recognize (or
assume) that there are some questions that we will never be able to
answer, and that is one of them.
Every day we read in the media about accidents, conflicts or
catastrophes in different parts of the world in which large numbers of
people die. If we let these stories affect us the way they should, we
could not function in our daily lives. Somehow, we have to filter out
most of this information and only respond emotionally to only some of
it. Sometimes a story about the fate or suffering of just one person
reaches many more people emotionally than a story about the suffering
of thousands. People often find it easier to empathize with an
individual than with many people.
How bad, exactly, does a catastrophe with million deaths seem to us by comparison to just one death? It is possible to do a psychology experiment to answer that question. Without going into detail, we can anticipate the outcome. The ratio in this case is evidently much less than a million to one - at least in our experience and imagination. Perhaps
it is the square root? Do a million deaths seem a thousand times worse
than one death? If that were the case, a million deaths would seem a
hundred times worse than a hundred deaths, and ten times worse than ten
thousand deaths. When making claims like this, we are engaging in
Obviously, the estimates in the previous paragraph are very
approximate. The consideration of very approximate estimates is
characteristic of HQE. The idea is that it is often better to make some
kind of calculation than none at all. In fact, the results of
approximate calculations can often be very revealing. They can guide
important ethical decisions. I will argue that we need calculations of
this kind to help us make the most important decisions of all -
decisions that could mean life and death for milllions of people.
Approximate calculations play an important role in physics. Sometimes,
they only involve powers of ten. In the example in the previous
paragraph, a million is 106 and a thousand is 103. So we might claim that 106 deaths seem 103 worse than 100
deaths. In this example, we are concerned to get the exponents about
right; we assume the the first exponent is 6 rather than 5 or 7, and
the second is 3 rather than 4 or 2. This may seem overly approximate,
but physicists often find this way of thinking very useful, for example
when considering enormous versus tiny distances. The size of the
universe is about 1027 m and the Planck length is about 10-35 m. Don't worry about increasing the accuracy of such numbers before digesting the exponents!
HQE uses order-of-magnitude estimates to get a feel for the real human
consequences of future catastophes such as a nuclear war or dangerous
climate change. It is a way of getting beyond human subjectivity, which
as we have seen cannot handle enormous numbers of deaths. Instead the
aims is to treat every person as equally valuable, and respond to
future threats accordingly.
The importance of HQE
Needless to say humanity is not very good as considering the future
human costs of future actions. In the foreseeable future, the result of
this failure may be the biggest catastophe that humanity has ever
experienced - if not human extinction. HQE can help us to get a grip on
this problem. We should be focusing a lot of expert effort into this
fledgling academic discipline and not ignoring it as if our children
did not exist or did not matter. The opinions
this page are the
Suggestions for improving or extending the content
welcome (parncutt at gmx dot at).
Back to Richard Parncutt's homepage