Last week, I posted several articles on population ethics - the question of "How many people should there be?"
Before moving on, I want to post an article that addresses this question more directly. It does not give an answer, but it gives directions for finding an answer that works better than the traditional approach.
That traditional approach is based on a false absumption that, in turn, leads to absurd results. The false assumption is that value exists as an intrinsic property with an assignable value, and that morality demands that we make this intrinsic value as big as possible. Applied to population ethics, it says that a life with fulfilled desires has intrinsic value, and we need to maximize the lives that are worth living. This, in turn, leads to what philosophers call the "repugnant conclusion." We should create the maximum number of barely tolerable lives because a small number of large values (higher quality lives) will, at some point, inevitably be exceeded by a sufficiently large number of very small values. That is, unless the large values can grow to infinity. In this case, the idea that the quality of life can approach infinity seems false.
As Derik Parfit wrote:
For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better even though its members have lives that are barely worth living.
This argument requires the assumption that each life us assigned an intrinsic value independent of interests or desires (though the intrinsic value of a life at depend on how many of the person's desires are fulfilled). Or job - our moral duty - is to make this number as big as possible.
Desirism rejects that model.
It asks a different question. "What reasons for action do we have to bring additional people into the world?"
Where populations are small, additional people contribute to the greater fulfillment of desires. Those who exist in such a world have many and strong reasons to promote interests that increase the population.
To see this, imagine one person living utterly alone, and the benefits of adding just one more person. Where there are two, add a third. Each new person provides significant improvements to everybody's quality of life. Yet, in all but extreme circumstances such as on a lifeboat, they place little additional strain on available resources.
However, at some point adding new people produces less of a benefit; the law of diminishing returns applies. Additional people compete for resources - driving up prices or contributing to scarcity. Yet, the diminishing returns of this additional person is quite small. At some point, people have more and stronger reasons to promote interests that maintain this population - that motivate people to pursue options other than bringing more people into the world.
Note that a tribe living on a small island or a small oasis in a hostile desert will reach this point sooner than a global community capable of efficient global trade.
I would like to stress that what desirism suggests to look at is is not interests TO bring more or fewer people into the world but interests THAT bring more or fewer people into the world. What reason do we have to encourage women to become interested in science, medicine, politics, consulting, and ends that would be thwarted by having children, thus motivating them not to select that option? What reasons do we have to promote interests in non-procreative sex over procreative sex - such as is provided through the use of birth control?
Where bringing more people into the world thwarts more and stronger of our desires, where we have reason to avoid greater competition for scarce goods and services, we have more and stronger reason to promote alternative interests.
It is arguably the case that we have passed this point. The next billion people will put heavy demands on the environment and resources such as food, clean water, and energy. Yet, they will not likely contribute more than the current seven billion people can contribute. We have passed the point where we have reason to promote interests in having more children.
Should we be having more people? The answer is found by looking at the reasons for action that exist for promoting interests that will increase the population over promoting interests that will maintain or reduce it.
I think it is important that desirism, unlike the traditional model, matches the way that population ethics is actually discussed by people who are concerned with population policy. The traditional view has created a great deal of philosophical literature. Yet, to the public at large, this is "How many angels can dance on the head of a pin?" philosophy. Some people find it interesting to try to anwer it, but it yields no substantive and useful conclusions.
Desirism, on the other hand, focuses attention on the very types of issues that people interested in population policy are interested in. Specifically, how much strain will additional people put on the environment, and on resources such as water, land, and energy? What are the possibilities that population pressures will lead to conflict? At the same time, what are the chances that an increased population can take advantages of economies of scale and specialization and trade to produce an overall increase in the standard of living?
The "repugnant conclusion" - and all arguments in that family - should be taken as reductio-ad-absurdum arguments against the idea that there are intrinsic values in the world to be maximized. If a set of premises leads to an absurd conclusion, it is time to question those premises. In this case, it is time to discard the belief that lives have intrinsic value.
Value is real - but it is not an intrinsic value. It is a relational value. A true value claim relates a state of affairs to a set of desires. Desires provide the only real-world reason for action.
To determine whether we should bring more people into the world, we need to be asking, "What reasons for action do we have for promoting interests that increase the number of people, and what reasons for action do we have for promoting interests that would lower this number?"