What Is The Tragedy Of The Commons Essay

Main thesis = Freedom in a commons brings ruin to all.[1]

Note the author's self-critique:

"The dilemma, as Hardin reassessed 30 years after his original essay, is not that the atmosphere is a commons, but that it is an unmanaged commons, an open-access regime. “To judge from the critical literature,” he wrote in the May 1, 1998 issue of Science, “the weightiest mistake in my synthesizing paper was the omission of the modifying adjective ‘unmanaged’.” [2]


Garreth Harding, in a classic and often quoted essay, had argued that the Commons inevitably leads to the abuse of common resources. The essay is located at http://dieoff.org/page95.htm

The author himself "has criticized misinterpretations of his work with the lament that "The title of my 1968 paper should have been The Tragedy of the Unmanaged Commons. (cited here [3])

Please also read this Refutation of the Tragedy of the Commons, by Ian Angus.


"The tragedy of the commons is a type of social trap that involves a conflict over resources between individual interests and the common good. The term derives originally from a parable published by William Forster Lloyd in his 1833 book on population. It was then popularized and extended by Garrett Hardin in his 1968 Science essay "The Tragedy of the Commons".[1] However, the theory itself is as old as Aristotle who said: "That which is common to the greatest number has the least care bestowed upon it"." (http://en.wikipedia.org/wiki/Tragedy_of_the_commons)



"Hardin explains his “Tragedy of the Commons in the following way. “Picture a pasture open to all. It is to be expected that each herdsman will try to keep as many cattle as possible on the commons.

“As a rational being, each herdsman seeks to maximize his gain. The rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another….

“But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy.

“Each man is locked into a system that compels him to increase his herd without limit — in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons.

“The individual benefits as an individual from his ability to deny the truth even though society as a whole, of which he is a part, suffers. Education can counteract the natural tendency to do the wrong thing, but the inexorable succession of generations requires that the basis for this knowledge be constantly refreshed.

In 1968 Hardin was able to articulate the following example, one that we face today. Our “National Parks present another instance of the working out of the tragedy of the commons. At present, they are open to all, without limit” but “the parks themselves are limited in extent whereas population seems to grow without limit. The values that visitors seek in the parks are steadily eroded. Plainly, we must soon cease to treat the parks as commons or they will be of no value to anyone.” (http://www.openeducation.net/2008/02/21/the-digital-commons-%e2%80%93-left-unregulated-are-we-destined-for-tragedy/)


"The Tragedy of the Commons is a leading social science paradigm largely based on a Garret Hardin's 1968 Science article by that name. Hardin postulates a commons pasture that is open to all and examines the position of a commons herdsman who is deciding whether to add an animal to his herd.

Hardin applies the following utility model:

  • if the herdsman adds the animal, he will gain the full benefit from the sale of this animal (+1)
  • while there will be a cost to the commons due to additional overgrazing (-1), the effects of overgrazing by this additional animal are shared by all of the herdsmen (n) and this herdsman will only bear a fraction of that cost (-1 / n)
  • after calculating the net utilities, the rational herdsman concludes that the only sensible course is to add the animal

As a result, the herdsman adds the animal and then continues to add animals. In parallel, the same conclusion is reached and the same course of action is taken by every other herdsman that is sharing the commons pasture. In the words of Hardin: "Therein is the tragedy. Each man is locked into a system that compels him to increase his herd without limit--in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. Freedom in a commons brings ruin to all." (http://www.osbr.ca/ojs/index.php/osbr/article/view/740/706)


See also the in-depth discussion in The Tragedy of the “Tragedy of the Commons”. By Achim Lerch. (was at www.boell.org/downloads/Lerch_Tragedy.pdf - gone away 2017)

Misreading Hardin

David Harvey:

"I have lost count of the number of times I have seen Garrett Hardin’s classic article, “The Tragedy of the Commons,”1 cited as an irrefutable argument for the superior efficiency of private property rights with respect to land and resource uses and, therefore, as an irrefutable justification for privatization. This mistaken reading in part derives from Hardin’s appeal to the metaphor of cattle, under the private ownership of several individuals concerned with maximizing their individual utility, pastured on a piece of common land. If the cattle were held in common, of course, the metaphor would not work. It would then be clear that it was private property in cattle and individual utility-­ aximizing behavior that lay at the heart of the problem. But none of this was Hardin’s fundamental concern. His preoccupation was population growth. The personal decision to have children would, he feared, lead eventually to the destruction of the global commons (a point that Thomas Malthus also argued). The private, familial nature of the decision was the crucial problem. The only solution, in his view, was authoritarian regulatory population control.

I cite Hardin’s logic here to highlight the way that thinking about the com- mons itself has been enclosed all too often in a far too narrow set of presumptions, largely driven by the example of the land enclosures that occurred in Britain from the sixteenth century onward. As a result, thinking has often polarized between private-­ roperty solutions or authoritarian state intervention." (Radical History Review Issue 109 (Winter 2011)

The Main Mistakes of Hardin's Fable

John Tierney:

"His fable about a common pasture that is ruined by overgrazing became one of the most-quoted articles ever published by that journal, and it served as a fundamental rationale for the expansion of national and international regulation of the environment. His fable was a useful illustration of a genuine public-policy problem — how do you manage a resource that doesn’t belong to anyone? — but there were a couple of big problems with the essay and its application.

First, Dr. Hardin himself misapplied the fable. Declaring that “overpopulation” was a tragedy of the commons, he warned that “freedom to breed will bring ruin to all.” He and others advocated a “lifeboat ethic” of denying food aid, even during emergencies, to poor countries with rapidly growing populations. But “overpopulation” was not even a theoretical example of the tragedy of the commons. Parents are not like the cattle owners who profit individually by adding cows to the pasture (while collectively destroying it). Parents, unlike the cattle owners, have to pay to feed and house and educate their children, and the high economic costs of children are one reason that birth rates have declined around the world — without any of the coercion discussed by Dr. Hardin and some other ecologists (like Paul Ehrlich).

The second problem arising from Dr. Hardin’s fable was the presumption that a commons needed to be regulated by national and international agencies. Dr. Hardin didn’t explicitly make that generalization in the essay — he noted that the tragedy could be avoided either by regulating the commons or by converting it to private property — but others in the environmental movement essentially drew that conclusion. Although some greens talked about the virtue of “acting locally,” major environmental groups lobbied in Washington for expanded federal authority, and they urged the rest of the world to follow the American and European example by creating national rules governing commons like forests and fisheries.

But too often those commons ended up in worse shape once they were put under the control of distant bureaucrats who lacked the expertise or the incentives to do the job properly. Dr. Hardin and his disciples had failed to appreciate how often the tragedy of the commons had been averted thanks to ingenious local institutions and customs. Dr. Ostrom won the Nobel for her work analyzing those local institutions. In an interview at the Mercatus Center at George Mason University, Dr. Ostrom discussed the damage that had been done by those who had supplanted the local institutions." (http://tierneylab.blogs.nytimes.com/2009/10/15/the-non-tragedy-of-the-commons/)

Hardin's Confusions: On the Difference between Common Pool Resources and Common Property Regimes

George Caffentzis in a presentation on the Neo-Hardinians scholars of the Commons:

"Scholars in the neo-Hardinian tendency have carried on many important empirical studies of common property systems across the planet as well as have made a number of important distinctions in the study of common property. This is not the place to assess their empirical studies (cf. the extensive bibliography on Private and Common Property Rights in (Ostrom 2000: 352-379) and the Digital Library on the Commons mentioned above), but their most important theoretical distinctions are worth reviewing, since some can be useful to the anti-capitalist commonist movement.

Of course, the primary one is between common property and open access regimes, since the confusion between them is the basis of Hardin's deduction of the tragedy of the common. Common property regimes are "where the members of a clearly demarcated group have a legal right to exclude nonmembers of that group from using a resource. Open access regimes (res nullius)-including the classic cases of the open seas and the atmosphere-have long been considered in legal doctrine as involving no limits on who is authorized to use a resource" (Ostrom 2000: 335-336). On the basis of this distinction, common property and open access regimes are mutually exclusive and anyone who had as their political ideal the creation of an open access regime would not be a supporter of the commons.

The second important distinction is between a common-pool resource (which is a thing or stuff) and a common property regime (which is a set of social relations). A common-pool resource is such that (a) "it is costly to exclude individuals from using the good either through physical barriers or legal instruments and (b) the benefits consumed by one individual subtract from the benefits available to others" (Ostrom 2000: 337). Because of its two defining characteristics, a common-pool resource is subject to problems of congestion, overuse and potential destruction. Access to, withdrawal from, management and ownership of such a resource can be in the form of a common property regime, but it need not be. "Examples exist of both successful and unsuccessful efforts to govern and manage common-pool resources by governments, communal groups, cooperatives, voluntary associations, and private individuals or firms" (Ostrom 2000: 338). Much of the work of the neo-Hardinians has been to study what attributes of common-pool resources that "are conducive to the use of communal proprietorship or ownership" and what attributes of common-pool resources that "are conducive to individual rights to withdrawal, management, exclusion and alienation" (Ostrom 2000: 332).

The neo-Hardinians, however, seem to be less interested in the fact that not all common property regimes involve common-pool resources. On the contrary, when we examine the history of common property regimes, we must conclude that many have been based on non-common-pool resources. For example, money income, personal belongings, literary texts, and even children have been communalized. Thus the 15th century Taborites' first act of forming their community was to dump all their personal belongings in large open chests and begin their communal relations on an even footing (Federici 2004: 54). On the basis of the history of common property regimes it is difficult to decide what types of goods are "conducive" to private property and what kinds of goods are "conducive" to common property.

The third important distinction is between common-pool resources (e.g., a fishery, a river) and public goods (e.g., knowledge of a physical law, living in a just and peaceful society). They share one characteristic, i.e., it is difficult to exclude people living within the scope of these resources or goods from their enjoyment. But they also differ in another characteristic, for a common-pool resource like a fishery is reduced when something of value like a particular fish is withdrawn from it while a public good like knowledge of the Second Law of Thermodynamics is not diminished when still another person uses it to construct a new engine." (http://www.globaljusticecenter.org/papers/caffentzis.htm)

Flaming as a Tragedy of the Commons

Clay Shirky: "Flaming is one of a class of economic problems known as The Tragedy of the Commons. Briefly stated, the tragedy of the commons occurs when a group holds a resource, but each of the individual members has an incentive to overuse it. (The original essay used the illustration of shepherds with common pasture. The group as a whole has an incentive to maintain the long-term viability of the commons, but with each individual having an incentive to overgraze, to maximize the value they can extract from the communal resource.) In the case of mailing lists (and, again, other shared conversational spaces), the commonly held resource is communal attention. The group as a whole has an incentive to keep the signal-to-noise ratio low and the conversation informative, even when contentious. Individual users, though, have an incentive to maximize expression of their point of view, as well as maximizing the amount of communal attention they receive. It is a deep curiosity of the human condition that people often find negative attention more satisfying than inattention, and the larger the group, the likelier someone is to act out to get that sort of attention." (http://shirky.com/writings/group_user.html)

More by Shirky on the group 'as its own worst enemy', at http://shirky.com/writings/group_enemy.html; the highly recommended Shirky archive is at http://shirky.com

The Tragedy of the Anti-Commons

Steve Webber on the "the tragedy of the anti-commons." Let's say I'm a researcher working at a small biotech firm here in the Bay Area. And I think there's something interesting I would like to do with a particular molecule and its interaction with a particular gene. Much of this stuff is now patented, and there are so many competing patent claims on so many different parts of the things I would need to work on, that the cost of actually figuring out what permissions I need are astronomical. So lots of small companies simply can't work on it.

They call it the tragedy of the anti-commons in the sense that in order to work on this, they've got to get a permission to use this molecule and a license to play with this gene. That's just too expensive, so they walk away from it. I don't have a quantitative model that can describe for you how much wasted effort or dead weight results from this problem. But I can tell you, there's a lot of anecdotal evidence. There are companies that patent gene sequences, knowing full well that these patents would never be upheld in court, because they haven't added any value. They also know full well that if a pharmaceutical company decides it wants to do something with that gene, it's more likely just to pay the company $150,000 or $200,000, rather than spend a year or 18 months fighting the patent in court. It's kind of tragic."

See the related entries on:

  1. Tragedy of the Anti-Commons
  2. Tragedy of the Non-Commons

There is no Tragedy of the Commons or Free Riding online!

Timothy B. Lee:

"The idea of "free riding" is based on a couple of key 20th-century assumptions that just don't apply to the online world. The first assumption is that the production of content is a net cost that must either be borne by the producer or compensated by consumers. This is obviously true for some categories of content—no one has yet figured out how to peer-produce Hollywood-quality motion pictures, for example—but it's far from universal. Moreover, the real world abounds in counterexamples. No one loses sleep over the fact that people "free ride" off of watching company softball games, community orchestras, or amateur poetry readings. To the contrary, it's understood that the vast majority of musicians, poets, and athletes find these activities intrinsically enjoyable, and they're grateful to have an audience "free ride" off of their effort.

The same principle applies to Wikipedia. Participating in Wikipedia is a net positive experience for both readers and editors. We don't need to "solve" the free rider problem because there are more than enough people out there for whom the act of contributing is its own reward.

The second problem with the "free riding" frame is that it fails to appreciate that the sheer scale of the Internet changes the nature of collective action problems. With a traditional meatspace institution like a church, business or intramural sports league, it's essential that most participants "give back" in order for the collective effort to succeed. The concept of "free riding" emphasizes the fact that traditional offline institutions expect and require reciprocation from the majority of their members for their continued existence. A church in which only, say, one percent of members contributed financially wouldn't last long. Neither would an airline in which only one percent of the customers paid for their tickets.

On Wikipedia—and a lot of other online content-creation efforts—the ratio of contributors to users just doesn't matter. Because the marginal cost of copying and distributing content is very close to zero, institutions can get along just fine with arbitrarily high "free riding" rates. All that matters is whether the absolute number of contributors is adequate. And because some fraction of new users will always become contributors, an influx of additional "free riders" is almost always a good thing.

Talking about peer production as solving a "free-rider problem," then, gets things completely backwards. The biggest danger collaborative online projects face is not "free riding" but obscurity. A tiny free software project in which every user contributes code is in a much worse position than a massively popular software project like Firefox in which 99.9 percent of users "free ride." Obviously, every project would like to have more of its users become contributors. But the far more important objective for an online collaborative effort to is grow the total size of the user community. New "free riders" are better than nothing." (http://freedom-to-tinker.com/blog/tblee/trouble-free-riding)


Knowledge is the only resource that grows by use. It cannot be depleted by use. This is the most simple refutation of the Tragedy of the Commons when applied to knowledge in general and to digital data specifically. All types of intellectual goods (publications, algorithms, science, software, all data in general) can only prosper and grow when they are put to use by as many people and in as many contexts as possible. An idea has to spread from one mind to another to eventually be able to manifest in humanity's reality as a material good, concept or model. All else is nothing but a potentiality.

Going Beyond the Tragedy of the Commmons

Ugo Mattei:

"Tragedy of the Commons: Two World Views in Conflict Competition v. Cooperation

"As Adam Smith put it, “We are not ready to suspect any person of being defective in selfishness.”[14] To put is quite simply, this is the central assumption underpinning Hardin’s analysis. Only the crude application of the model of homo oeconomicus [15], an individual maximizer of short-time utility, explains the results (and academic success) of the so-called “tragedy of the commons.”[16] In fact, the well known parable of the microbiologist Garret Hardin, presented to the public in a famous essay in 1968, now “refuted” by Nobel laureate in economics (2009) Elinor Ostrom, has perverted the ordinary wisdom to see the commons as a place of no law. According to Hardin, a common resource, as freely appropriable stimulates the opportunistic behavior of accumulation and ultimately destructive and “inefficient” consumption. This reasoning conjures up the image of a person invited to a buffet where food is freely accessible, and rather than sharing the bounty with others, rushes to try to maximize the amount of calories that can be stored at the expense of others, efficiently consuming the largest possible amount of food in the least possible time.' Hardin & Olsen (free rider theory) in their models assume a) that humans are “rational actors” in the sense that they are wealth maximizers b) that self interest has nothing to do with community interest c) communication and its role in trust building are not considerations d) all commons are open access regimes rather than common property regimes which have established rules of benefits and responsibility. The sense of limits set naturally within a community of respect towards others and nature is excluded from their model, failing to consider the qualitative relationships essential to an analysis of a community resource management based on participation of a (still) civilized human being.

The “Tragedy of the Commons” highlights two worldviews in conflict. The dominant worldview being substantially based on the Darwinian idea, which makes “competition,” “struggle,” and “emulation” between physical and legal persons the essence of reality. The other is a recessive view, which vanished from practice in the West long ago (and is under attack in places such as the African or Andean village community where it is still partially resistant); this view is instead based on an ecological and holistic view of the world and displays relationship, cooperation and community as its typical pattern. The dominant model is constantly proposed in the rhetoric of growth, progress and development (synonymous with one another as ways “up” and “out” of poverty) used by government, non- governmental organizations, and the media, despite the current catastrophic ecological and economic situation in which we find ourselves. This dominant model considers the alternative one as the legacy of a medieval political-legal experience, where feudal fragmentation of power is maintained, paternalism dominates in a view of society at odds with the modern liberal conception of governance. To be sure, at a purely analytical level, in the recessive model we find at the center of social life the pre-state guild community. [18] There are a number of possible narratives capable of explaining the abandonment of this community based model in the West, the most relevant for our purposes is a economic historical narrative which views its demise as the product of “progressive” modernizing market forces relying on state-wide political institutions. It is a fact that the alliance between state institutions and private property interests has been the force behind the race for colonial plunder and increased concentration of capital (the original accumulation of Marxian memory). The recessive model, still present in the organization of communities in the “periphery” (the West being the center) suffered and continues to suffer a merciless assault by the structural adjustment and comprehensive development plans of the World Bank and International Monetary Fund, protracting the model of the early enclosures to the very present. Such mechanisms have encouraged and resulted in the “commodification” of land, and of local knowledge, supported by a process of cultural adjustment (human rights, rule of law, gender equality etc. ) that serves as justifying rhetoric for continuity in plunder.

Going Beyond the Tragedy

Elinor Ostrom and her team of social scientists successfully dispelled the myth, established as truth by Garret Hardin’s “Tragedy of the Commons,” of the superiority of private property rights in resource management. She demonstrated through an overwhelming amount of empirical evidence that cooperative property arrangements are in fact successful, and that Hardin’s case rather than been the rule, as previously believed, is in fact an exception and only apply to a minority of situations. While Ostrom’s work undeniably marks a critical turning point in economic theory, it still remains trapped between the state v. private dichotomy. Without consideration of the historical, political, and legal context of the fierce public and private debate, Ostrom’s findings remains limited in their applicability. Property law from its early development in the West (Rome & English Feudalism) acted to justify the power of dominant sovereigns over weaker subjects in the effort to secure resources. Property law continued to persist in this direction by “terra nullus” doctrines during the period of Colonialism. In more recent times, such domination has taken on a more subtle and hegemonic form. When viewed in context, Hardin was far from the naïve microbiologist who happened to find applicability for evolutionary theory in the realm of political economy, rather he contributed to a long lineage of economists and lawyers, securing a place for radical individualism and eventual dismantlement of the public domain in favor of private interests. Hardin’s work contributes to the work done in the 50s and 60s by Freidman, Buchanan, Tollock, and Olsen of the radical individualist school and early neo classical economics that eventually led in the 70s and 80s to the Chicago school, and the Law and Econ movement with its primary purpose of dismantling the public in favor of private interests.

Given the pervasiveness of the false opposition of: state v. market/private property and competition v. cooperation, individual v. community, one should be suspicious of taxonomies trying to make order out of many types of commons (natural commons – environment, water, etc.. – vs. social commons – culture, knowledge, historical remembrances) that do not fully embrace the needed shift to a more phenomenological understanding of our current historical moment. These suggestions (and much of the Nobel prized liberal literature on the commons) should be thoroughly examined critically so as to avoid reproducing again the traditional mechanistic view, the separation between object and subject and resulting commodification. Alongside the empirical data now available, we must critically assess our current institutions and reclaim our common sense about the issue of resource distribution, perverted too long by the neo liberal agenda. The commons project must be as much about a new framework for participatory government as alternative property arrangements. In Notebooks Gramsci explains his notion of common sense, which refers to ” the philosophy of the non-philosophers.” In other words when a certain ideology filters into the mass consciousness and is naturalized into the “common sense.” Gramsci explains that the task of renewing the common sense depends upon the articulation by intellectuals of a counterhegemonic narrative capable of challenging the status quo. The holistic revolution, or ecological view of the world may present exactly the narrative capable of renewing the common sense and paving the way for the commons.' (http://www.uninomade.org/preliminary-question-about-the-commons/)

More Information

  1. The Wikipedia article is at http://en.wikipedia.org/wiki/Tragedy_of_the_commons
  2. Essay by Eleanor Ostrom: Coping with Tragedies of the Commons
  3. Refutation of the Tragedy of the Commons; The Non-Tragedy of the Commons
  4. Tragedy of the Anti-Commons
  5. Carpenter, Stanley R. 2000. "Sustainability and Common-Pool Resources: Alternatives to Tragedy." Society for Philosophy and Technology 3(4).
  6. c2 wiki, with many comments: Tragedy of the Commons


The population problem has no technical solution; it requires a fundamental extension in morality.

At the end of a thoughtful article on the future of nuclear war, Wiesner and York (1) concluded that: "Both sides in the arms race are ...confronted by the dilemma of steadily increasing military power and steadily decreasing national security. It is our considered professional judgment that this dilemma has no technical solution. If the great powers continue to look for solutions in the area of science and technology only, the result will be to worsen the situation."

I would like to focus your attention not on the subject of the article (national security in a nuclear world) but on the kind of conclusion they reached, namely that there is no technical solution to the problem. An implicit and almost universal assumption of discussions published in professional and semipopular scientific journals is that the problem under discussion has a technical solution. A technical solution may be defined as one that requires a change only in the techniques of the natural sciences, demanding little or nothing in the way of change in human values or ideas of morality.

In our day (though not in earlier times) technical solutions are always welcome. Because of previous failures in prophecy, it takes courage to assert that a desired technical solution is not possible. Wiesner and York exhibited this courage; publishing in a science journal, they insisted that the solution to the problem was not to be found in the natural sciences. They cautiously qualified their statement with the phrase, "It is our considered professional judgment... ." Whether they were right or not is not the concern of the present article. Rather, the concern here is with the important concept of a class of human problems which can be called "no technical solution problems," and, more specifically, with the identification and discussion of one of these.

It is easy to show that the class is not a null class. Recall the game of tick-tack-toe. Consider the problem, "How can I win the game of tick-tack-toe?" It is well known that I cannot, if I assume (in keeping with the conventions of game theory) that my opponent understands the game perfectly. Put another way, there is no "technical solution" to the problem. I can win only by giving a radical meaning to the word "win." I can hit my opponent over the head; or I can drug him; or I can falsify the records. Every way in which I "win" involves, in some sense, an abandonment of the game, as we intuitively understand it. (I can also, of course, openly abandon the game--refuse to play it. This is what most adults do.)

The class of "No technical solution problems" has members. My thesis is that the "population problem," as conventionally conceived, is a member of this class. How it is conventionally conceived needs some comment. It is fair to say that most people who anguish over the population problem are trying to find a way to avoid the evils of overpopulation without relinquishing any of the privileges they now enjoy. They think that farming the seas or developing new strains of wheat will solve the problem--technologically. I try to show here that the solution they seek cannot be found. The population problem cannot be solved in a technical way, any more than can the problem of winning the game of tick-tack-toe.

What Shall We Maximize?

Population, as Malthus said, naturally tends to grow "geometrically," or, as we would now say, exponentially. In a finite world this means that the per capita share of the world's goods must steadily decrease. Is ours a finite world?

A fair defense can be put forward for the view that the world is infinite; or that we do not know that it is not. But, in terms of the practical problems that we must face in the next few generations with the foreseeable technology, it is clear that we will greatly increase human misery if we do not, during the immediate future, assume that the world available to the terrestrial human population is finite. "Space" is no escape (2).

A finite world can support only a finite population; therefore, population growth must eventually equal zero. (The case of perpetual wide fluctuations above and below zero is a trivial variant that need not be discussed.) When this condition is met, what will be the situation of mankind? Specifically, can Bentham's goal of "the greatest good for the greatest number" be realized?

No--for two reasons, each sufficient by itself. The first is a theoretical one. It is not mathematically possible to maximize for two (or more) variables at the same time. This was clearly stated by von Neumann and Morgenstern (3), but the principle is implicit in the theory of partial differential equations, dating back at least to D'Alembert (1717-1783).

The second reason springs directly from biological facts. To live, any organism must have a source of energy (for example, food). This energy is utilized for two purposes: mere maintenance and work. For man, maintenance of life requires about 1600 kilocalories a day ("maintenance calories"). Anything that he does over and above merely staying alive will be defined as work, and is supported by "work calories" which he takes in. Work calories are used not only for what we call work in common speech; they are also required for all forms of enjoyment, from swimming and automobile racing to playing music and writing poetry. If our goal is to maximize population it is obvious what we must do: We must make the work calories per person approach as close to zero as possible. No gourmet meals, no vacations, no sports, no music, no literature, no art. ... I think that everyone will grant, without argument or proof, that maximizing population does not maximize goods. Bentham's goal is impossible.

In reaching this conclusion I have made the usual assumption that it is the acquisition of energy that is the problem. The appearance of atomic energy has led some to question this assumption. However, given an infinite source of energy, population growth still produces an inescapable problem. The problem of the acquisition of energy is replaced by the problem of its dissipation, as J. H. Fremlin has so wittily shown (4). The arithmetic signs in the analysis are, as it were, reversed; but Bentham's goal is still unobtainable.

The optimum population is, then, less than the maximum. The difficulty of defining the optimum is enormous; so far as I know, no one has seriously tackled this problem. Reaching an acceptable and stable solution will surely require more than one generation of hard analytical work--and much persuasion.

We want the maximum good per person; but what is good? To one person it is wilderness, to another it is ski lodges for thousands. To one it is estuaries to nourish ducks for hunters to shoot; to another it is factory land. Comparing one good with another is, we usually say, impossible because goods are incommensurable. Incommensurables cannot be compared.

Theoretically this may be true; but in real life incommensurables are commensurable. Only a criterion of judgment and a system of weighting are needed. In nature the criterion is survival. Is it better for a species to be small and hideable, or large and powerful? Natural selection commensurates the incommensurables. The compromise achieved depends on a natural weighting of the values of the variables.

Man must imitate this process. There is no doubt that in fact he already does, but unconsciously. It is when the hidden decisions are made explicit that the arguments begin. The problem for the years ahead is to work out an acceptable theory of weighting. Synergistic effects, nonlinear variation, and difficulties in discounting the future make the intellectual problem difficult, but not (in principle) insoluble.

Has any cultural group solved this practical problem at the present time, even on an intuitive level? One simple fact proves that none has: there is no prosperous population in the world today that has, and has had for some time, a growth rate of zero. Any people that has intuitively identified its optimum point will soon reach it, after which its growth rate becomes and remains zero.

Of course, a positive growth rate might be taken as evidence that a population is below its optimum. However, by any reasonable standards, the most rapidly growing populations on earth today are (in general) the most miserable. This association (which need not be invariable) casts doubt on the optimistic assumption that the positive growth rate of a population is evidence that it has yet to reach its optimum.

We can make little progress in working toward optimum population size until we explicitly exorcize the spirit of Adam Smith in the field of practical demography. In economic affairs, The Wealth of Nations (1776) popularized the "invisible hand," the idea that an individual who "intends only his own gain," is, as it were, "led by an invisible hand to promote . . . the public interest" (5). Adam Smith did not assert that this was invariably true, and perhaps neither did any of his followers. But he contributed to a dominant tendency of thought that has ever since interfered with positive action based on rational analysis, namely, the tendency to assume that decisions reached individually will, in fact, be the best decisions for an entire society. If this assumption is correct it justifies the continuance of our present policy of laissez-faire in reproduction. If it is correct we can assume that men will control their individual fecundity so as to produce the optimum population. If the assumption is not correct, we need to reexamine our individual freedoms to see which ones are defensible.

Tragedy of Freedom in a Commons

The rebuttal to the invisible hand in population control is to be found in a scenario first sketched in a little-known pamphlet (6) in 1833 by a mathematical amateur named William Forster Lloyd (1794-1852). We may well call it "the tragedy of the commons," using the word "tragedy" as the philosopher Whitehead used it (7): "The essence of dramatic tragedy is not unhappiness. It resides in the solemnity of the remorseless working of things." He then goes on to say, "This inevitableness of destiny can only be illustrated in terms of human life by incidents which in fact involve unhappiness. For it is only by them that the futility of escape can be made evident in the drama."

The tragedy of the commons develops in this way. Picture a pasture open to all. It is to be expected that each herdsman will try to keep as many cattle as possible on the commons. Such an arrangement may work reasonably satisfactorily for centuries because tribal wars, poaching, and disease keep the numbers of both man and beast well below the carrying capacity of the land. Finally, however, comes the day of reckoning, that is, the day when the long-desired goal of social stability becomes a reality. At this point, the inherent logic of the commons remorselessly generates tragedy.

As a rational being, each herdsman seeks to maximize his gain. Explicitly or implicitly, more or less consciously, he asks, "What is the utility to me of adding one more animal to my herd?" This utility has one negative and one positive component.

1) The positive component is a function of the increment of one animal. Since the herdsman receives all the proceeds from the sale of the additional animal, the positive utility is nearly +1.

2) The negative component is a function of the additional overgrazing created by one more animal. Since, however, the effects of overgrazing are shared by all the herdsmen, the negative utility for any particular decision-making herdsman is only a fraction of –1.

Adding together the component partial utilities, the rational herdsman concludes that the only sensible course for him to pursue is to add another animal to his herd. And another; and another... But this is the conclusion reached by each and every rational herdsman sharing a commons. Therein is the tragedy. Each man is locked into a system that compels him to increase his herd without limit--in a world that is limited. Ruin is the destination toward which all men rush, each pursuing his own best interest in a society that believes in the freedom of the commons. Freedom in a commons brings ruin to all.

Some would say that this is a platitude. Would that it were! In a sense, it was learned thousands of years ago, but natural selection favors the forces of psychological denial (8). The individual benefits as an individual from his ability to deny the truth even though society as a whole, of which he is a part, suffers.

Education can counteract the natural tendency to do the wrong thing, but the inexorable succession of generations requires that the basis for this knowledge be constantly refreshed.

A simple incident that occurred a few years ago in Leominster, Massachusetts, shows how perishable the knowledge is. During the Christmas shopping season the parking meters downtown were covered with plastic bags that bore tags reading: "Do not open until after Christmas. Free parking courtesy of the mayor and city council." In other words, facing the prospect of an increased demand for already scarce space. the city fathers reinstituted the system of the commons. (Cynically, we suspect that they gained more votes than they lost by this retrogressive act.)

In an approximate way, the logic of the commons has been understood for a long time, perhaps since the discovery of agriculture or the invention of private property in real estate. But it is understood mostly only in special cases which are not sufficiently generalized. Even at this late date, cattlemen leasing national land on the western ranges demonstrate no more than an ambivalent understanding, in constantly pressuring federal authorities to increase the head count to the point where overgrazing produces erosion and weed-dominance. Likewise, the oceans of the world continue to suffer from the survival of the philosophy of the commons. Maritime nations still respond automatically to the shibboleth of the "freedom of the seas." Professing to believe in the "inexhaustible resources of the oceans," they bring species after species of fish and whales closer to extinction (9).

The National Parks present another instance of the working out of the tragedy of the commons. At present, they are open to all, without limit. The parks themselves are limited in extent--there is only one Yosemite Valley--whereas population seems to grow without limit. The values that visitors seek in the parks are steadily eroded. Plainly, we must soon cease to treat the parks as commons or they will be of no value to anyone.

What shall we do? We have several options. We might sell them off as private property. We might keep them as public property, but allocate the right to enter them. The allocation might be on the basis of wealth, by the use of an auction system. It might be on the basis of merit, as defined by some agreed-upon standards. It might be by lottery. Or it might be on a first-come, first-served basis, administered to long queues. These, I think, are all the reasonable possibilities. They are all objectionable. But we must choose--or acquiesce in the destruction of the commons that we call our National Parks.


In a reverse way, the tragedy of the commons reappears in problems of pollution. Here it is not a question of taking something out of the commons, but of putting something in--sewage, or chemical, radioactive, and heat wastes into water; noxious and dangerous fumes into the air, and distracting and unpleasant advertising signs into the line of sight. The calculations of utility are much the same as before. The rational man finds that his share of the cost of the wastes he discharges into the commons is less than the cost of purifying his wastes before releasing them. Since this is true for everyone, we are locked into a system of "fouling our own nest," so long as we behave only as independent, rational, free-enterprisers.

The tragedy of the commons as a food basket is averted by private property, or something formally like it. But the air and waters surrounding us cannot readily be fenced, and so the tragedy of the commons as a cesspool must be prevented by different means, by coercive laws or taxing devices that make it cheaper for the polluter to treat his pollutants than to discharge them untreated. We have not progressed as far with the solution of this problem as we have with the first. Indeed, our particular concept of private property, which deters us from exhausting the positive resources of the earth, favors pollution. The owner of a factory on the bank of a stream--whose property extends to the middle of the stream, often has difficulty seeing why it is not his natural right to muddy the waters flowing past his door. The law, always behind the times, requires elaborate stitching and fitting to adapt it to this newly perceived aspect of the commons.

The pollution problem is a consequence of population. It did not much matter how a lonely American frontiersman disposed of his waste. "Flowing water purifies itself every 10 miles," my grandfather used to say, and the myth was near enough to the truth when he was a boy, for there were not too many people. But as population became denser, the natural chemical and biological recycling processes became overloaded, calling for a redefinition of property rights.

How To Legislate Temperance?

Analysis of the pollution problem as a function of population density uncovers a not generally recognized principle of morality, namely: the morality of an act is a function of the state of the system at the time it is performed (10). Using the commons as a cesspool does not harm the general public under frontier conditions, because there is no public, the same behavior in a metropolis is unbearable. A hundred and fifty years ago a plainsman could kill an American bison, cut out only the tongue for his dinner, and discard the rest of the animal. He was not in any important sense being wasteful. Today, with only a few thousand bison left, we would be appalled at such behavior.

In passing, it is worth noting that the morality of an act cannot be determined from a photograph. One does not know whether a man killing an elephant or setting fire to the grassland is harming others until one knows the total system in which his act appears. "One picture is worth a thousand words," said an ancient Chinese; but it may take 10,000 words to validate it. It is as tempting to ecologists as it is to reformers in general to try to persuade others by way of the photographic shortcut. But the essense of an argument cannot be photographed: it must be presented rationally--in words.

That morality is system-sensitive escaped the attention of most codifiers of ethics in the past. "Thou shalt not . . ." is the form of traditional ethical directives which make no allowance for particular circumstances. The laws of our society follow the pattern of ancient ethics, and therefore are poorly suited to governing a complex, crowded, changeable world. Our epicyclic solution is to augment statutory law with administrative law. Since it is practically impossible to spell out all the conditions under which it is safe to burn trash in the back yard or to run an automobile without smog-control, by law we delegate the details to bureaus. The result is administrative law, which is rightly feared for an ancient reason--Quis custodiet ipsos custodes?--"Who shall watch the watchers themselves?" John Adams said that we must have "a government of laws and not men." Bureau administrators, trying to evaluate the morality of acts in the total system, are singularly liable to corruption, producing a government by men, not laws.

Prohibition is easy to legislate (though not necessarily to enforce); but how do we legislate temperance? Experience indicates that it can be accomplished best through the mediation of administrative law. We limit possibilities unnecessarily if we suppose that the sentiment of Quis custodiet denies us the use of administrative law. We should rather retain the phrase as a perpetual reminder of fearful dangers we cannot avoid. The great challenge facing us now is to invent the corrective feedbacks that are needed to keep custodians honest. We must find ways to legitimate the needed authority of both the custodians and the corrective feedbacks.

Freedom To Breed Is Intolerable

The tragedy of the commons is involved in population problems in another way. In a world governed solely by the principle of "dog eat dog"--if indeed there ever was such a world--how many children a family had would not be a matter of public concern. Parents who bred too exuberantly would leave fewer descendants, not more, because they would be unable to care adequately for their children. David Lack and others have found that such a negative feedback demonstrably controls the fecundity of birds (11). But men are not birds, and have not acted like them for millenniums, at least.

If each human family were dependent only on its own resources; if the children of improvident parents starved to death; if, thus, overbreeding brought its own "punishment" to the germ line--then there would be no public interest in controlling the breeding of families. But our society is deeply committed to the welfare state (12), and hence is confronted with another aspect of the tragedy of the commons.

In a welfare state, how shall we deal with the family, the religion, the race, or the class (or indeed any distinguishable and cohesive group) that adopts overbreeding as a policy to secure its own aggrandizement (13)? To couple the concept of freedom to breed with the belief that everyone born has an equal right to the commons is to lock the world into a tragic course of action.

Unfortunately this is just the course of action that is being pursued by the United Nations. In late 1967, some 30 nations agreed to the following (14):

It is painful to have to deny categorically the validity of this right; denying it, one feels as uncomfortable as a resident of Salem, Massachusetts, who denied the reality of witches in the 17th century. At the present time, in liberal quarters, something like a taboo acts to inhibit criticism of the United Nations. There is a feeling that the United Nations is "our last and best hope," that we shouldn't find fault with it; we shouldn't play into the hands of the archconservatives. However, let us not forget what Robert Louis Stevenson said: "The truth that is suppressed by friends is the readiest weapon of the enemy." If we love the truth we must openly deny the validity of the Universal Declaration of Human Rights, even though it is promoted by the United Nations. We should also join with Kingsley Davis (15) in attempting to get Planned Parenthood-World Population to see the error of its ways in embracing the same tragic ideal.

Conscience Is Self-Eliminating

It is a mistake to think that we can control the breeding of mankind in the long run by an appeal to conscience. Charles Galton Darwin made this point when he spoke on the centennial of the publication of his grandfather's great book. The argument is straightforward and Darwinian.

People vary. Confronted with appeals to limit breeding, some people will undoubtedly respond to the plea more than others. Those who have more children will produce a larger fraction of the next generation than those with more susceptible consciences. The difference will be accentuated, generation by generation.

In C. G. Darwin's words: "It may well be that it would take hundreds of generations for the progenitive instinct to develop in this way, but if it should do so, nature would have taken her revenge, and the variety Homo contracipiens would become extinct and would be replaced by the variety Homo progenitivus" (16).

The argument assumes that conscience or the desire for children (no matter which) is hereditary--but hereditary only in the most general formal sense. The result will be the same whether the attitude is transmitted through germ cells, or exosomatically, to use A. J. Lotka's term. (If one denies the latter possibility as well as the former, then what's the point of education?) The argument has here been stated in the context of the population problem, but it applies equally well to any instance in which society appeals to an individual exploiting a commons to restrain himself for the general good--by means of his conscience. To make such an appeal is to set up a selective system that works toward the elimination of conscience from the race.

Pathogenic Effects of Conscience

The long-term disadvantage of an appeal to conscience should be enough to condemn it; but has serious short-term disadvantages as well. If we ask a man who is exploiting a commons to desist "in the name of conscience," what are we saying to him? What does he hear? --not only at the moment but also in the wee small hours of the night when, half asleep, he remembers not merely the words we used but also the nonverbal communication cues we gave him unawares? Sooner or later, consciously or subconsciously, he senses that he has received two communications, and that they are contradictory: (i) (intended communication) "If you don't do as we ask, we will openly condemn you for not acting like a responsible citizen"; (ii) (the unintended communication) "If you do behave as we ask, we will secretly condemn you for a simpleton who can be shamed into standing aside while the rest of us exploit the commons."

Everyman then is caught in what Bateson has called a "double bind." Bateson and his co-workers have made a plausible case for viewing the double bind as an important causative factor in the genesis of schizophrenia (17). The double bind may not always be so damaging, but it always endangers the mental health of anyone to whom it is applied. "A bad conscience," said Nietzsche, "is a kind of illness."

To conjure up a conscience in others is tempting to anyone who wishes to extend his control beyond the legal limits. Leaders at the highest level succumb to this temptation. Has any President during the past generation failed to call on labor unions to moderate voluntarily their demands for higher wages, or to steel companies to honor voluntary guidelines on prices? I can recall none. The rhetoric used on such occasions is designed to produce feelings of guilt in noncooperators.

For centuries it was assumed without proof that guilt was a valuable, perhaps even an indispensable, ingredient of the civilized life. Now, in this post-Freudian world, we doubt it.

Paul Goodman speaks from the modern point of view when he says: "No good has ever come from feeling guilty, neither intelligence, policy, nor compassion. The guilty do not pay attention to the object but only to themselves, and not even to their own interests, which might make sense, but to their anxieties" (18).

One does not have to be a professional psychiatrist to see the consequences of anxiety. We in the Western world are just emerging from a dreadful two-centuries-long Dark Ages of Eros that was sustained partly by prohibition laws, but perhaps more effectively by the anxiety-generating mechanism of education. Alex Comfort has told the story well in The Anxiety Makers (19); it is not a pretty one.

Since proof is difficult, we may even concede that the results of anxiety may sometimes, from certain points of view, be desirable. The larger question we should ask is whether, as a matter of policy, we should ever encourage the use of a technique the tendency (if not the intention) of which is psychologically pathogenic. We hear much talk these days of responsible parenthood; the coupled words are incorporated into the titles of some organizations devoted to birth control. Some people have proposed massive propaganda campaigns to instill responsibility into the nation's (or the world's) breeders. But what is the meaning of the word responsibility in this context? Is it not merely a synonym for the word conscience? When we use the word responsibility in the absence of substantial sanctions are we not trying to browbeat a free man in a commons into acting against his own interest? Responsibility is a verbal counterfeit for a substantial quid pro quo. It is an attempt to get something for nothing.

If the word responsibility is to be used at all, I suggest that it be in the sense Charles Frankel uses it (20). "Responsibility," says this philosopher, "is the product of definite social arrangements." Notice that Frankel calls for social arrangements--not propaganda.

Mutual Coercion Mutually Agreed upon

The social arrangements that produce responsibility are arrangements that create coercion, of some sort. Consider bank-robbing. The man who takes money from a bank acts as if the bank were a commons. How do we prevent such action? Certainly not by trying to control his behavior solely by a verbal appeal to his sense of responsibility. Rather than rely on propaganda we follow Frankel's lead and insist that a bank is not a commons; we seek the definite social arrangements that will keep it from becoming a commons. That we thereby infringe on the freedom of would-be robbers we neither deny nor regret.

The morality of bank-robbing is particularly easy to understand because we accept complete prohibition of this activity. We are willing to say "Thou shalt not rob banks," without providing for exceptions. But temperance also can be created by coercion. Taxing is a good coercive device. To keep downtown shoppers temperate in their use of parking space we introduce parking meters for short periods, and traffic fines for longer ones. We need not actually forbid a citizen to park as long as he wants to; we need merely make it increasingly expensive for him to do so. Not prohibition, but carefully biased options are what we offer him. A Madison Avenue man might call this persuasion; I prefer the greater candor of the word coercion.

Coercion is a dirty word to most liberals now, but it need not forever be so. As with the four-letter words, its dirtiness can be cleansed away by exposure to the light, by saying it over and over without apology or embarrassment. To many, the word coercion implies arbitrary decisions of distant and irresponsible bureaucrats; but this is not a necessary part of its meaning. The only kind of coercion I recommend is mutual coercion, mutually agreed upon by the majority of the people affected.

To say that we mutually agree to coercion is not to say that we are required to enjoy it, or even to pretend we enjoy it. Who enjoys taxes? We all grumble about them. But we accept compulsory taxes because we recognize that voluntary taxes would favor the conscienceless. We institute and (grumblingly) support taxes and other coercive devices to escape the horror of the commons.

An alternative to the commons need not be perfectly just to be preferable. With real estate and other material goods, the alternative we have chosen is the institution of private property coupled with legal inheritance. Is this system perfectly just? As a genetically trained biologist I deny that it is. It seems to me that, if there are to be differences in individual inheritance, legal possession should be perfectly correlated with biological inheritance--that those who are biologically more fit to be the custodians of property and power should legally inherit more. But genetic recombination continually makes a mockery of the doctrine of "like father, like son" implicit in our laws of legal inheritance. An idiot can inherit millions, and a trust fund can keep his estate intact. We must admit that our legal system of private property plus inheritance is unjust--but we put up with it because we are not convinced, at the moment, that anyone has invented a better system. The alternative of the commons is too horrifying to contemplate. Injustice is preferable to total ruin.

It is one of the peculiarities of the warfare between reform and the status quo that it is thoughtlessly governed by a double standard. Whenever a reform measure is proposed it is often defeated when its opponents triumphantly discover a flaw in it. As Kingsley Davis has pointed out (21), worshippers of the status quo sometimes imply that no reform is possible without unanimous agreement, an implication contrary to historical fact. As nearly as I can make out, automatic rejection of proposed reforms is based on one of two unconscious assumptions: (i) that the status quo is perfect; or (ii) that the choice we face is between reform and no action; if the proposed reform is imperfect, we presumably should take no action at all, while we wait for a perfect proposal.

But we can never do nothing. That which we have done for thousands of years is also action. It also produces evils. Once we are aware that the status quo is action, we can then compare its discoverable advantages and disadvantages with the predicted advantages and disadvantages of the proposed reform, discounting as best we can for our lack of experience. On the basis of such a comparison, we can make a rational decision which will not involve the unworkable assumption that only perfect systems are tolerable.

Recognition of Necessity

Perhaps the simplest summary of this analysis of man's population problems is this: the commons, if justifiable at all, is justifiable only under conditions of low-population density. As the human population has increased, the commons has had to be abandoned in one aspect after another.

First we abandoned the commons in food gathering, enclosing farm land and restricting pastures and hunting and fishing areas. These restrictions are still not complete throughout the world.

Somewhat later we saw that the commons as a place for waste disposal would also have to be abandoned. Restrictions on the disposal of domestic sewage are widely accepted in the Western world; we are still struggling to close the commons to pollution by automobiles, factories, insecticide sprayers, fertilizing operations, and atomic energy installations.

In a still more embryonic state is our recognition of the evils of the commons in matters of pleasure. There is almost no restriction on the propagation of sound waves in the public medium. The shopping public is assaulted with mindless music, without its consent. Our government is paying out billions of dollars to create supersonic transport which will disturb 50,000 people for every one person who is whisked from coast to coast 3 hours faster. Advertisers muddy the airwaves of radio and television and pollute the view of travelers. We are a long way from outlawing the commons in matters of pleasure. Is this because our Puritan inheritance makes us view pleasure as something of a sin, and pain (that is, the pollution of advertising) as the sign of virtue?

Every new enclosure of the commons involves the infringement of somebody's personal liberty. Infringements made in the distant past are accepted because no contemporary complains of a loss. It is the newly proposed infringements that we vigorously oppose; cries of "rights" and "freedom" fill the air. But what does "freedom" mean? When men mutually agreed to pass laws against robbing, mankind became more free, not less so. Individuals locked into the logic of the commons are free only to bring on universal ruin; once they see the necessity of mutual coercion, they become free to pursue other goals. I believe it was Hegel who said, "Freedom is the recognition of necessity."

The most important aspect of necessity that we must now recognize, is the necessity of abandoning the commons in breeding. No technical solution can rescue us from the misery of overpopulation. Freedom to breed will bring ruin to all. At the moment, to avoid hard decisions many of us are tempted to propagandize for conscience and responsible parenthood. The temptation must be resisted, because an appeal to independently acting consciences selects for the disappearance of all conscience in the long run, and an increase in anxiety in the short.

The only way we can preserve and nurture other and more precious freedoms is by relinquishing the freedom to breed, and that very soon. "Freedom is the recognition of necessity"--and it is the role of education to reveal to all the necessity of abandoning the freedom to breed. Only so, can we put an end to this aspect of the tragedy of the commons.


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