On the Buddhist Truths and the Paradoxes in

  Population Ethics



     B.Contestabile    admin@socrethics.com                                                           First version 2007   Last version 2015








Starting point

Starting point of this paper is the following citation concerning the state of contemporary population ethics:

“Most discussion in population ethics has concentrated on how to evaluate populations in regard to their goodness, that is, how to order populations by the relations “is better than” and “is as good as”. This field has been riddled with paradoxes which purport to show that our considered beliefs are inconsistent in cases where the number of people and their welfare varies.” [Arrhenius 2004, 201].



Type of problem

The best known and most discussed example shattering our intuitions is Parfit’s

Mere Addition Paradox. This paper explores the potential of the Buddhist Truths to answer the following questions:

         What is at the source of the Mere Addition Paradox?

         Why are paradoxes unavoidable in population ethics?



The Mere Addition Paradox

The seemingly uncontroversial classical utilitarian axiology allows expanding a population at the cost of life’s quality, a finding which is called Repugnant Conclusion

[Parfit, 387-390].




The Repugnant Conclusion can be avoided by assuming that additional lives do not improve the state of affairs:

         However, the higher the quality of the additional lives is thought to be, the more this assumption becomes counter-intuitive, a consequence which is called Reverse Repugnant Conclusion

         The Reverse Repugnant Conclusion loses its counter-intuitivity, if non-existence is seen as a perfect state (instead of a neutral state). According to the Buddhist Truths perfection can only be reached by eliminating desires and finally dissolving the ego. The closeness of perfection and non-existence (of the ego) is the key to escape the Reverse Repugnant Conclusion.



Intuition and Interest

The comparison of classical utilitarian and Buddhist intuitions demonstrates the close tie between intuitions and interests. The perplexing Buddhist intuition about non-existence contrasts sharply with the vital interest to procreate. Following a brief description of the basic (conflicting) interests and corresponding intuitions:

         The vital interest to expand life – which may originate in the merciless biological utility function – favors the classical utilitarian intuition that the total amount of welfare is more important than the average quality of welfare.

         The hedonistic interest to avoid suffering (dhukka) – combined with the Buddhist emphasis on compassion – favors the intuition that the total amount of welfare is less important than the average quality of welfare.

The more one of the two interests is devaluated at the cost of the other, the more the combination becomes counter-intuitive for the majority:

         According to the classical utilitarian axiology it is correct to slightly decrease the average quality of life in favour of a larger population (with a higher total amount of welfare). But when this devaluation results in lives “barely worth living”, it becomes counter-intuitive for the majority, see Repugnant Conclusion [Stanford, chapter 1].

         According to the perfectionist Buddhist axiology it is correct to slightly decrease the size of a population (and the total amount of welfare) in favour of a higher average quality of life. But when this devaluation results in a “near zero” population, it becomes counter-intuitive for most non-Buddhists, see Reverse Repugnant Conclusion [Arrhenius, 54][Stanford, chapter 2.4].

Obviously at some point the repetition of a plausible procedure yields a counter-intuitive result; an experience which is perceived as a paradox.



The impossibility theorem

Gustav Arrhenius – after having systematically investigated the most important axiologies and intuitions – came to the conclusion that there is no normative theory which coheres with “our” moral beliefs [Arrhenius 2000, 265]. This result is immediately plausible on the basis of the following consideration:

         Population ethics using a two parameter model (welfare and population size) can be characterized by a conflict of interest.

         Conflicting interests shape conflicting intuitions.

         Conflicting intuitions make it impossible to find a coherent normative theory.


In order to find a coherent theory one would have to find a universal interest and a corresponding universal intuition. The obvious candidate to meet this request is sympathy. But since there is no universal consensus on the desirable degree of sympathy, the normative force of such an approach is limited.


Breaking out of the two-parameter model and accepting the incommensurability of certain qualities threatens the normative claim of population ethics.



Concluding remark

The conflict between quantity and quality in population ethics can be described without referring to Buddhism, of course. The perfectionist Buddhist axiology (a kind of negative average utilitarianism) is of special interest because it removes counter-intuitive conclusions of positive utilitarianism (and vice-versa). It is accordingly suited to illustrate the tie between intuitions and interests.











The full text was published 2010 in


Contemporary Buddhism, Volume 11, Issue 1


pp. 103-113









Addendum:  How many people should there be? 







Table of Contents


1.    Introduction

2.    The different qualities of welfare are assumed to be commensurable

3.    The different qualities of welfare are assumed to be incommensurable

4.    Normative Guideline

5.    Conflicts with other norms









1.  Introduction


The human population has been growing continuously since the end of the Black Death, around the year 1400, although the most significant increase has been in the last 50 years, mainly due to medical advancements, increases in agricultural productivity and the historically unique availability of abundant cheap energy (Overpopulation, Wikipedia)

The question “How many people should there be?” has gained importance with environmental problems and with the scarcity of resources such as fresh water and food. The following comic, published in the Curator, 9.Mar, 2011, illustrates the problem:






According to Gustav Arrhenius [Arrhenius 2004, 201] there is no coherent theoretical answer to the question “How many people should there be?”

In the following we have a look at some practical approaches. They depend on various assumptions:




2.  The different qualities of welfare are assumed to be commensurable



Positive total welfare

Classical utilitarianism has the deficiency, that it favors expansion at the cost of the quality of life:

Example: A population Z, consisting of 500 billion individuals, each with a life that is barely worth living, is better than a population A consisting of 1 billion individuals, each having lives that are of extremely high quality – as long as the sum of happiness (welfare) is greater in Z than in A. (Derek Parfit's Repugnant Conclusion)



Repugnant Conclusion 2



This diagram was taken from the internet (Author: Stanford Encyclopedia of Philosophy)



Total welfare can be increased by increasing the quality of life instead of the population’s size. But the fact that “improving the quality takes more energy than reproducing the same quality” favours expansion at the cost of quality.


         It is easier to copy an invention than to invest in research (e.g. generic drugs)

         It is easier to procreate than to improve the quality of life


Expansive population policies at the cost of quality can be prevented by comparing averages:

The most popular theory among welfare economists, Average Utilitarianism, ranks populations according to the average welfare per life in the population [Arrhenius 2000, 53].

Average utilitarianism says that the best population size is the one that produces the highest average welfare.

Despite of its theoretical deficiencies [Arrhenius 2000, 53-57][Broome, 191-195] this normative guideline has some influence on national policies.


In our context the term welfare stands for life satisfaction, i.e. it is not restricted to economic welfare.

The term classical utilitarianism is not used in its historical meaning. It stands for advanced versions like the one of John Broome [Broome].



Negative total welfare

Insofar as the Speed Limit example [Contestabile 2010, 110-111] is concerned with the distribution of welfare among a fixed number of people; it does not contribute to population ethics [Arrhenius 2000, 110]. Its relevance concerns the comparison with an empty population.

         If the suffering of the traffic victims surpasses the happiness of the drivers, then – according to classical utilitarianism – it is better to stop mobile traffic.

         If the suffering within a population surpasses its happiness, then – according to the same logic – it is better to stop procreation; non-existence is the lesser evil.

But the empty population is only a theoretical option. In practice it is impossible to eradicate humanity by global voluntary childlessness or by a conscious violent self-destruction. Populations with negative total welfare have to be analysed like the mirror image of populations with positive total welfare.

Contractive population policies at the cost of quality – the so called Negative Repugnant Conclusion [Broome, 213] – can be prevented by comparing averages.

In analogy to positive average utilitarianism (see above) the best population size is the one that produces the least negative average welfare.



The sign of total welfare

The following assumptions decide about the sign of total welfare:

The notion of a life worth living:

1.      If non-existence is considered to be the worst case, then every life is worth living and total welfare is necessarily positive. Classical utilitarianism often adopts this axiology without explicitly mentioning it [Broome, 2-12].

2.      If non-existence is considered to be the best case, then no life is worth living:

a.    If non-existence is assigned the value zero, then total welfare is necessarily negative [Stanford, chapter 2.4]

b.   If non-existence is seen as a perfect state (as in the version of Buddhism mentioned above), then it is given the maximum value, or it is considered to be incommensurable [Contestabile 2014, 308-309].

3.      If the value of non-existence is equalized with the value of a neutral life [Broome, 142] and if the value of a neutral life is set to zero [Broome, 257] then a life worth living is understood as a life with positive welfare. In this case total welfare can be positive or negative.

Within case (3) it is decisive, how suffering is measured relative to happiness:

a.      Current surveys on life satisfaction suggest that total welfare is positive.

b.      If suffering is given a higher weight than in surveys, then total welfare may turn negative; see Hostility and the Minimization of Suffering.



Intuition and interest

Above assumptions are shaped by conflicting interests [Contestabile 2010, 109]:

         The interest to expand life – in particular combined with cultural optimism – favors negative intuitions about non-existence:

o   It favors the intuition that existence is better than non-existence. Suffering is devaluated relative to happiness. The hedonistic scale contains positive and negative values, but the positive ones are given more weight. See (3a) above.

o   It also favors the radical intuition that non-existence is the worst case. Within the hedonistic scale even horrible lives are given a positive sign and are labeled “worth living”. The language is instrumentalized by the interest. See (1) above.

         The interest to avoid suffering – in particular combined with cultural pessimism – favors positive intuitions about non-existence:

o   It favors the intuition that non-existence is the lesser evil [Contestabile 2014, 303]. Happiness is devaluated relative to suffering. The hedonistic scale contains positive and negative values, but the negative ones are given more weight. See (3b) above.

o   It also favors the radical intuition that non-existence is the best case [Contestabile 2014, 306]. Within the hedonistic scale even happy lives are labeled “not worth living”. The language is instrumentalized by the interest. See (2) above.


The predominating assumption that total welfare is positive, might be the result of a distorted perception, caused by the biological interest to expand life, see Negative Utilitarianism and Buddhist Intuition.




3.  The different qualities of welfare are assumed to be incommensurable


The Speed Limit example [Contestabile 2010, 110-111] is useful to raise the question of incommensurability, because it compares the convenience of the car drivers with the suffering of traffic victims.

The aggregation of incommensurable preferences is the most general approach to solve conflicts of interest (like quantity versus quality). The “repugnancy” of a population [Contestabile 2010, 105] can be considered to be a matter of individual preference. A majority-definition of “repugnancy” is then derived by aggregating the individual preferences for competing combinations of population-size and welfare. If the individuals are well informed about the consequences of a certain population policy and if they can freely express their attitude towards risk, then the aggregation of their preferences delivers an inter-subjective criterion to decide between policies.




4.  Normative Guideline


For ethicists, majority decisions are not a satisfying answer to the question “How many people should there be?”

Majority decisions may overrule normative guidelines, but they do not replace them.

The basis for any norm in population ethics is commensurability. If surveys measure welfare (life satisfaction) with point scales or percentages, then the different qualities of welfare become commensurable. Under this premise the following normative proposals could make sense:

         For both, positive and negative total welfare, the best population size is the one that produces the highest average welfare.

         A prioritarian weighting function should be applied, so that the lower levels of welfare get more weight within the average. The weighing function prevents the improvement of the average at the cost of a minority.


In other words: The goal of population policy is to support the long-term improvement of (weighted) average welfare.


This guideline solves the problem of defining overpopulation:


There is no strict demographic definition of the word overpopulation. How would we define it?

1)      In terms of population density? If so, Bermuda would be more overpopulated than Bangladesh.

2)      In terms of rates of "natural increase"? In that case, Pre-Revolutionary America (1763-1776) would have been more overpopulated than contemporary Haiti.

3)      In terms of the "dependency ratio" of children and the elderly to working-age populations? That would mean Canada was more overpopulated in 1965 than India is today!

(Starved for ideas)


         According to above guideline overpopulation is reached when an increasing population starts to decrease the average welfare.

         Conversely “underpopulation” is reached, when a shrinking population starts to decrease the average welfare. A shrinking population is in conflict with the biological utility function. With a few exceptions – like Buddhist sanghas – this conflict decreases the average welfare at some point.

The correlation between population size and welfare (life satisfaction) has to be explored by happiness economics.






René Magritte Golconda




5.  Conflicts with other norms



Human rights

Is reproductive liberty a human right?

Although reproductive liberty is not specifically listed as an individual right in the Universal Declaration of Human Rights (1948), a variety of UN declarations, resolutions, covenants and conventions have been taken to justify the claim that reproduction within the family is a fundamental human right [Kates, 29]


The claim that reproduction is a human right gets support by the thesis that self-regulation is the best policy, similar to the self-regulation by Adams Smith’s invisible hand.


1)      The social system is too complex to make predictions. Within the family the consequences of parenthood are much easier to foresee than on the society level. For the parents it may be foreseeable that an additional child makes a positive contribution to welfare.

2)      The suffering of the possible parents from childlessness (or from not having an additional child) is unequally distributed. Families with many children compensate childless families in such a way that prescriptions are dispensable.

3)      If resources become scarce, then the incentive increases to find technological solutions.


Opponents of reproductive liberty have no confidence in self-regulation:

If population growth continues unabated, we fear the problems of development will be "solved" by rises in death rates. For this reason, efforts to slow population growth should be treated as a human rights issue (Population: Enough of us now, Ehrlich Paul and Anne)

In other words: If reproductive liberty is counted among human rights, then it not only conflicts with population ethics, but also with other human rights.


A compromise could be to influence birth rates indirectly without explicitly prescribing the number of children.

       According to empirical data the idea that people should be coerced into having fewer babies misses the point. Birth rates fall with death rates (i.e. by defeating famine and diseases) and with the availability of contraceptives [MacKenzie].

       It seems that the migration of the rural population into the megacities is an important factor in decreasing birth rates. In cities women have better access to information and are less controlled by tradition.

The best policy is probably – together with guaranteeing a decent standard of living – a form of (global) libertarian paternalism.



Intergenerational justice

If there is an intergenerational conflict of interests, present generations may be obligated by considerations of justice not to pursue policies that create benefits for themselves but impose costs on those who will live in the future (Intergenerational justice, Stanford Encyclopedia of Philosophy)

If humanity survives, the ones that disrespect birth control win from a biological point of view. But the price for survival might be an increase in suffering. In the case of limited resources and foreseeable catastrophes the protection of future generations requires restricting the liberty of the actual generation.


1.      If the world's population grows beyond 7.5 billion, mass starvation could well occur in many poorer parts of the world. Marxists and libertarians argue that the world can accommodate a continual increase in population through technological innovation and up to a point this is true. However, it is clearly apparent, even among developed countries that a higher population leads to a poorer quality of life – compare Britain and Australia for example. Unless you want to live like a battery chicken, technology can't help you without population control. In poor politically unstable countries like Rwanda over-population can lead to genocide.
Similarly, just because some countries can accommodate large numbers of people successfully doesn't mean the whole planet can. The world is increasingly an economically integrated whole with the more sparsely populated countries supplying natural resources and farm products for the densely populated regions. Under-populated countries don't really exist (
Why overpopulation matters)

2.      If the carbon technology induces global warming, it can be stopped by majority decision, even if the people in this branch of the industry lose their jobs. But if a majority works in the carbon industry and votes for politicians who promote their short-term interests, then future generations will have to pay the price for the welfare of the actual generation.

3.      If it were known, that mankind will be destructed within the next generation (e.g. by an asteroid) most people would agree that childlessness is an ethical duty. Overpopulation may cause catastrophes comparable to the one of an asteroid. But religions with a claim to power encourage their adherents to have many children, regardless of the available natural resources. Certain Koranic schools consider birth control to be a weapon of the United Nations in the fight against Islam [Padnos]. Intergenerational justice asks for a global implementation or remains a theoretical construct.


Above normative guideline makes sure that the actual generation does not enjoy life at the cost of future generations. So far it accords with the principle of intergenerational justice. However, as far as the guideline asks the actual generation to sacrifice themselves in order to improve the welfare of future generations, it conflicts with the principle. Again, the best policy is probably – together with guaranteeing a decent standard of living – a form of (global) libertarian paternalism, so that the restriction of reproductive liberty is not perceived as a major sacrifice.









  1. Arrhenius Gustav (2000), Future Generations, A Challenge for Moral Theory, FD-Diss., Uppsala University, Dept. of Philosopy, Uppsala: University Printers
  2. Arrhenius Gustav (2004), The Paradoxes of Future Generations and Normative Theory, in the Repugnant Conclusion, Essays on Population Ethics, 45-60, Dordrecht, Holland: Kluwer Academic Publications
  3. Broome John (2004), Weighing Lives, Oxford University Press, New York
  4. Contestabile Bruno (2010), On the Buddhist Truths and the Paradoxes in Population Ethics, Contemporary Buddhism, Vol.11, Issue 1, 103-113, Routledge, London
  5. Contestabile, Bruno (2014), Negative Utilitarianism and Buddhist Intuition, Contemporary Buddhism, Volume 15, Issue 2, pp. 298-311
  6. Kates Carol A. (2004), Reproductive Liberty and Overpopulation, Ithaca College
  7. MacKenzie, Debora (2008), The Population Paradox, in New Scientist, Nov.22
  8. Padnos Theo (2010), Undercover Muslim, Bodley Head, London, cited in Zürcher Tages-Anzeiger February 1, p.29
  9. Stanford Encyclopedia of Philosophy (2006), The Repugnant Conclusion