The Tragedy of the Commons PDF

What Shanl We Mam? Population, as Malthus said, naturally tends to grow "geometrically," or, as we...

What Shanl We Mam? 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 The Tragedy of the Commons capita share of the world's goods must steadily decrease. Is ours a finite world? A fair defense can be put forward for The population problem has no technical solution; the view that the world is infinite; or that we do not know that it is not. But, it requires a fundamental extension in morality. in terms of the practical problems that we must face in the next few genera- tions with the foreseeable technology, it Garrett Hardin 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 pop- At the end of a thoughtful article on sional judgment...." Vhether they ulation is finite. "Space" is no escape the future of nuclear war, Wiesner and were right or not is not the concern of (2). York (1) concluded that: "Both sides in the present article. Rather, the concern A finite world can support only a the arms race are... confronted by the here is with the important concept of a finite population; therefore, population dilemma of steadily increasing military class of human problems which can be growth must eventually equal zero. (The Downloaded from http://science.sciencemag.org/ on July 8, 2020 power and steadily decreasing national called "no technical solution problems," case of perpetual wide fluctuations security. It is our considered profes- and, more specifically, with the identifi- above and below zero is a trivial variant sional judgment that this dilemma has cation and discussion of one of these. that need not be discussed.) When this no technical solution. If the great pow- It is easy to show that the class is not condition is met, what will be the situa- ers continue to look for solutions in a null class. Recall the game of tick- tion of mankind? Specifically, can Ben- the area of science and technology only, tack-toe. Consider the problem, "How tham's goal of "the greatest good for the result will be to worsen the situa- can I win. the game of tick-tack-toe?" the greatest number" be realized? tion." It is well known that I cannot, if I as- No-for two reasons, each sufficient I would like to focus your attention sume (in keeping with the conventions by itself. The first is a theoretical one. not on the subject of the article (na- of game theory) that my opponent un- It is not mathematically possible to tional security in a nuclear world) but derstands the game perfectly. Put an- maximize for two (or more) variables at on the kind of conclusion they reached, other way, there is no "technical solu- the same time. This was clearly stated namely that there is no technical solu- tion" to the problem. I can win only by von Neumann and Morgenstern (3), tion to the problem. An implicit and by giving a radical meaning to the word but the principle is implicit in the theory almost universal assumption of discus- "win." I can hit my opponent over the of partial differential equations, dating sions published in professional and head; or I can drug him; or I can falsify back at least to D'Alembert (1717- semipopular scientific journals is that the records. Every way in which I "win" 1783). the problem under discussion has a involves, in some sense, an abandon- The second reason springs directly technical solution. A technical solution ment of the game, as we intuitively un- from biological facts. To live, any may be defined as one that requires a derstand it. (I can also, of course, organism must have a source of energy change only in. the techniques of the openly abandon the game-refuse to (for example, food). This energy is natural sciences, demanding little or play it. This is what most adults do.) utilized for two puposes: mere main- nothing in the way of change in human The class of "No technical solution tenance and work. For man, mainte- values or ideas of morality. problems" has members. My thesis is nance of life requires about 1600 kilo- In our day (though not in earlier that the "population problem," as con- calories a day ("maintenance calories'). times) technical solutions are always ventionally conceived, is a member of Anything that he does over and above welcome. Because of previous failures this class. How it is conventionally con- merely staying alive will be defined as in prophecy, it takes courage to assert ceived needs some comment. It is fair work, and is supported by "work cal- that a desired technical solution is not to say that most people who' anguish ories" which he takes in. Work calories possible. Wiesner and York exhibited over the population problem are trying are used not only for what we call work this courage; publishing in a science to find a way to avoid the evils of over- in common speech; they are also re- journal, they insisted that the solution population without relinquishing any of quired for all forms of enjoyment, from to the problem was not to be found in the privileges they now enjoy. They swimming and automobile racing to the natural sciences. They cautiously think that farming the seas or develop- playing music and writing poetry. If qualified their statement with the ing new strains of wheat will solve the our goal is to maximize population it is phrase, "It is our considered profes- problem-technologically. I try to show obvious what we must do: We must here that the solution they seek cannot make the work calories per person ap- The author is professor of biology, University of California, Santa Barbara. This article is be found. The population problem can- proach as close to zero as possible. No based on a presidential address presented before not be solved in a technical way, any gourmet meals, no vacations, no sports, the meeting of the Pacific Division of the Ameri- can Association for the Advancement of Science more than can the problem of winning no music, no literature, no art.... I at Utah State University, Logan, 25 June 1968. the game of tick-tack-toe. think that everyone will grant, without 13 DECEMBER 1968 1243 argument or proof, that maximizing time,-p - rate of zero. Any people volve unhappiness. For it is only by population does not max2imize goods. that has intuitively identified its opti- them that the futility of escape can be Bentham's goal is impossible. mum point will soon reach it, after made evident in the drama." In reaching this conclusion I have which its growth rate becomes and re- The tragedy of the commons develops made the usual assumption that it is mains zero. in this way. Picture a pasture open to the acquisition of energy that is the Of course, a positive growth rate all. It is to be expected that each herds- problem. The appearance of atomic might be taken as evidence that a pop- man will try to keep as many cattle as energy has led some to question this ulation is below its optimum. However, possible on the commons. Such an ar- assumption. However, given an infinite by any reasonable standards, the most rangement may work reasonably satis- source of energy, population growth rapidly growing populations on earth factorily for centuries because tribal still produces an inescapable problem. today are (in general) the most misera- wars, poaching, and disease keep the The problem of the acquisition of en- ble. This association (which need not be numbers of both man and beast well ergy is replaced by the problem of its invariable) casts doubt on the optimistic below the carrying capacity of the land. dissipation, as J. H. Fremlin has so wit- assumption that the positive growth rate Finally, however, comes the day of tily shown (4). The arithmetic signs in of a population is evidence that it has reckoning, that is, the day when the -t-he analysis are, as it were, reversed; yet to reach its optimum. long-desired goal of social stability be- but Bentham's goal is still unobtainable. We can make little progress in work- comes a reality. At this point, the in- The optimum population is, then, less ing toward optimum poulation size until herent logic of the commons remorse- than the maximum. The difficulty of we explicitly exorcize the spirit of lessly generates tragedy. defining the optimum is enormous; so Adam Smith in the field of practical As a rational being, each herdsman far as I know, no one has seriously demography. In economic affairs, The seeks to maximize his gain. Explicitly tackled this problem. Reaching an ac- Wealth of Nations (1776) popularized or implicitly, more or less consciously, Downloaded from http://science.sciencemag.org/ on July 8, 2020 ceptable and stable solution will surely the "invisible hand," the idea that an he asks, "What is the utility to me of require more than one generation of individual who "intends only his own adding one more animal to my herd?" hard analytical work-and much per- gain," is, as it were, "led by an invisible This utility has one negative and one suasion. hand to promote..,. the public interest" positive component. We want the maximum good per (5). Adam Smith did not assert that 1) The positive component is a func- person; but what is good? To one per- this was invariably true, and perhaps tion of the increment of one animal. son it is wilderness, to another it is ski neither did any of his followers. But he Since the herdsman receives all the lodges for thousands. To one it is estu- contributed to a dominant tendency of proceeds from the sale of the additional aries to nourish ducks for hunters to thought that has ever since interfered animal, the positive utility is nearly +1. shoot; to another it is factory land. with positive action based on rational 2) The negative component is a func- Comparing one good with another is, analysis, namely, the tendency to as- tion of the additional overgrazing we usually say, impossible because sume that decisions reached individually created by one more animal. Since, goods are incommensurable. Incommen- will, in fact, be the best decisions for an however, the effects of overgrazing are surables cannot be compared. entire society. If this assumption is shared by all the herdsmen, the negative Theoretically this may be true; but in correct it justifies the continuance of utility for any particular decision- real life incommensurables are commen- our present policy of laissez-faire in making herdsman is only a fraction of surable. Only a criterion of judgment reproduction. If it is correct we can as- -1. and a system of weighting are needed. sume that men will control their individ- Adding together the component par- In nature the criterion is survival. Is it ual fecundity so as to produce the opti- tial utilities, the rational herdsman better for a species to be small and hide- mum population. If the assumption is concludes that the only sensible course able, or large and powerful? Natural not correct, we need to reexamine our for him to pursue is to add another selection commensurates the incommen- individual freedoms to see which ones animal to his herd. And another; and surables. The compromise achieved de- are defensible. another.... But this is the conclusion pends on a natural weighting of the reached by each and every rational values of the variables. herdsman sharing a commons. Therein Man must imitate this process. There Tragedy of Freedom in a Commons is the tragedy. Each man is locked into is no doubt that in fact he already does, a system that compels him to increase but unconsciously. It is when the hidden The rebuttal to the invisible hand in his herd without limit-in a world that decisions are made explicit that the population control is to be found in a is limited. Ruin is the destination to- arguments begin. The problem for the scenario first sketched in a little-known ward which all men rush, each pursuing years ahead is to work out an accept- pamphlet (6) in 1833 by a mathematical his own best interest in a society that able theory of weighting. Synergistic amateur named William Forster Lloyd believes in the freedom of the com- effects, nonlinear variation, and difficul- (1794-1852). We may well call it "the mons. Freedom in a commons brings ties in discounting the future make the tragedy of the commons," using the ruin to all. intellectual problem difficult, but not word "tragedy" as the philosopher Some would say that this is a plati- (in principle) insoluble. Whitehead used it (7): "The essence of tude. Would that it were! In a sense, it Has any cultural group solved this dramatic tragedy is not unhappiness. It was learned thousands of years ago, but practical problem at the present time, resides in the solemnity of the remorse- natural selection favors the forces of even on an intuitive level? One simple less working of things." He then' goes on. psychological denial (8). The individual fact proves that none has: there is no to say, "This inevitableness of destiny benefits as an individual from his ability prosperous population in the world to- can only be illustrated in terms of hu- to deny the truth even though society as day that has, and has had for some man life by incidents which in fact in- a whole, of which he is a part, suffers. 1244 SCIENCE, VOL. 162 Education can counteract the natural upon standards. It might be by lottery. was a boy, for there were not too many tendency to do the wrong thing, but the Or it might be on a first-come, first- people. But as population became denser, inexorable succession of generations served basis, administered to long the natural chemical and biological re- requires that the basis for this knowl- queues. These, I think, are all the cycling processes became overloaded, edge be constantly refreshed. reasonable possibilities. They are all calling for a redefinition of property A simple incident that occurred a few objectionable. But we must choose-or rights. years ago in Leominster, Massachusetts, acquiesce in the destruction of the com- shows how perishable the knowledge is. mons that we call our National Parks. During the Christmas shopping season How To Legislate Temperance? the parking meters downtown were covered with plastic bags that bore tags Pollution Analysis of the pollution problem as reading: "Do not open until after Christ- a function of population density un- mas. Free parking courtesy of the In a reverse way, the tragedy of covers a not generally recognized prin- mayor and city council." In other words, the commons reappears in problems of ciple of morality, namely: the morality facing the prospect of an increased de- pollution. Here it is not a question of of an act of the state of is a function mand for already scarce space, the city taking something out of the commons, the system at the time it is performed fathers reinstituted the system of the but of putting something in-sewage, (10). Using the commons as a cesspool commons. (Cynically, we suspect that or chemical, radioactive, and heat does not harm the general public under they gained more votes than they lost wastes into water; noxious and danger- frontier conditions, because there is no by this retrogressive act.) ous fumes into the air; and distracting public; the same behavior in a metropo- In an approximate way, the logic of and unpleasant advertising signs into lis is unbearable. A hundred and fifty the commons has been understood for the line of sight. The calculations of years ago a plainsman could kill an Downloaded from http://science.sciencemag.org/ on July 8, 2020 a long time, perhaps since the dis- utility are much the same as before. American bison, cut out only the tongue covery of agriculture or the invention The rational man finds that his share of for his dinner, and discard the rest of of private property in real estate. But the cost of the wastes he discharges into the animal. He was not in any impor- it is understood mostly only in special the commons is less than the cost of tant sense being wasteful. Today, with cases which are not sufficiently general- purifying his wastes before releasing only a few thousand bison left, we ized. Even at this late date, cattlemen them. Since this is true for everyone, we would be appalled at such behavior. leasing national land on the western are locked into a system of "fouling our In passing, it is worth noting that the ranges demonstrate no more than an own nest," so long as we behave only morality of an act cannot be determined ambivalent understanding, in constantly as independent, rational, free-enter- from a photograph. One does not know pressuring federal authorities to increase prisers. whether a man killing an elephant or the head count to the point where over- The tragedy of the commons as a setting flre to the grassland is harming grazing produces erosion and weed- food basket is averted by private prop- others until one knows the total system dominance. Likewise, the oceans of the erty, or something formally like it. But in which his act appears. "One picture world continue to suffer from the sur- the air and waters surrounding us can- is worth a thousand words," said an vival of the philosophy of the commons. not readily be fenced, and so the trag- ancient Chinese; but it may take 10,000 Maritime nations still respond automat- edy of the commons as a cesspool must words to validate it. It is as tempting to ically to the shibboleth of the "freedom be prevented by different means, by co- ecologists as it is to reformers in general of the seas." Professing to believe in ercive laws or taxing devices that make to try to persuade others by way of the the "inexhaustible resources of the it cheaper for the polluter to treat his photographic shortcut. But the essense oceans," they bring species after species pollutants than to discharge them un- of an argument cannot be photo- of fish and whales closer to extinction treated. We have not progressed as far graphed: it must be presented rationally (9). with the solution of this problem as we -in words. The National Parks present another have with the first. Indeed, our particu- That morality is system-sensitive instance of the working out of the lar concept of private property, which escaped the attention of most codifiers tragedy of the commons. At present, deters us from exhausting the positive of ethics in the past. "Thou shalt they are open to all, without limit. The resources of the earth, favors pollution. not..." is the form of traditional parks themselves are limited in extent- The owner of a factory on the bank of ethical directives which make no allow- there is only one Yosemite Valley- a stream-whose property extends to ance for particular circumstances. The whereas population seems to grow with- the middle of the stream-often has laws of our society follow the pattern of out limit. The values that visitors seek difficulty seeing why it is not his natural ancient ethics, and therefore are poorly in the parks are steadily eroded. Plainly, right to muddy the waters flowing past suited to governing a complex, crowded, we must soon cease to treat the parks his door. The law, always behind the changeable world. Our epicyclic solu- as commons or they will be of no value times, requires elaborate stitching and tion is to augment statutory law with to anyone. fitting to adapt it to this newly perceived administrative law. Since it is practically What shall we do? We have several aspect of the commons. impossible to spell out all the conditions options. We might sell them off as pri- The pollution problem is a con- under which it is safe to burn trash in vate property. We might keep them as sequence of population. It did not much the back yard or to run an automobile public property, but allocate the right matter how a lonely American frontiers- without smog-control, by law we dele- to enter them. The allocation might be man disposed of his waste. "Flowing gate the details to bureaus. The result on the basis of wealth, by the use of an water purifies itself every 10 miles," my is administrative law, which is rightly auction system. It might be on the basis grandfather used to say, and the myth feared for an ancient reason-Quis of merit, as defined by some agreed- was near enough to the truth when he custodiet ipsos custodes?-"Who shall 13 DECEMBER 1968 1245 -A watch the watchers themselves?" John equal right to the commons is to lock cipiens would become extinct and Adams said that we must have "a gov- the world into a tragic course of action. would be replaced by the variety Homo ernment of laws and not men." Bureau Unfortunately this is just the course progenitivus" (16). administrators, trying to evaluate the of action that is being pursued by the The argument assumes that con- morality of acts in the total system, are United Nations. In late 1967, some 30 science or the desire for children (no singularly liable to corruption, produc- nations agreed to the following (14): matter which) is hereditary-but heredi- ing a government by men, not laws. The Universal Declaration of Human tary only in the most general formal Prohibition is easy to legislate Rights describes the family as the natural sense. The result will be the same (though not necessarily to enforce); but and fundamental unit of society. It fol- whether the attitude is transmitted how do we legislate temperance? Ex- lows that any choice and decision with through germ cells, or exosomatically, perience indicates that it can be ac- regard to the size of the family must irte- vocably rest with the family itself, and to use A. J. Lotka's term. (If one denies complished best through the mediation cannot be made by anyone else. the latter possibility as well as the of administrative law. We limit possi- former, then what's the point of educa- bilities unnecessarily if we suppose that It is painful to have to deny categor- ically the validity of this right; denying tion?) The argument has here been the sentiment of Quis custodiet denies stated in the context of the population us the use of administrative law. We it, one feels as uncomfortable as a resi- dent of Salem, Massachusetts, who problem, but it applies equally well to should rather retain the phrase as a any instance in which society appeals perpetual reminder of fearful dangers denied the reality of witches in the 17th century. At the present time, in liberal to an individual exploiting a commons we cannot avoid. The great challenge to restrain himself for the general facing us now is to invent the corrective quarters, something like a taboo acts to inhibit criticism of the United Nations. good-by means of his conscience. To feedbacks that are needed to keep cus- make such an appeal is to set up a todians honest. We must find ways to There is a feeling that the United Nations is "our last and best hope," selective system that works toward the legitimate the needed authority of both elimination of conscience from the race. Downloaded from http://science.sciencemag.org/ on July 8, 2020 the custodians and the corrective feed- that we shouldn't find fault with it; we backs. shouldn't play into the hands of the archconservatives. However, let us not forget what Robert Louis Stevenson Pathogenic Effects of Conscience Freedom To Breed Is Intolerable said: "The truth that is suppressed by friends is the readiest weapon of the The long-term disadvantage of an enemy." If we love the truth we must appeal to conscience should be enough The tragedy of the commons is in- openly deny the validity of the Universal to condemn it; but has serious short- volved in population problems in an- Declaration term disadvantages as well. If we ask other way. In a world governed solely though it is of Human Rights, even promoted by the United a man who is exploiting a commons to by the principle of "dog eat dog"-if Nations. We should also join with desist "in the name of conscience," indeed there ever was such a world- Kingsley Davis (15) in attempting to what are we saying to him? What does how many children a family had would get Planned Parenthood-World Popula- he hear?-not only at the moment but not be a matter of public concern. tion to see the error of its ways in em- also in the wee small hours of the Parents who bred too exuberantly would bracing the same tragic ideal. night when, half asleep, he remembers leave fewer descendants, not more, be- not merely the words we used but also cause they would be unable to care the nonverbal communication cues we adequately for their children. David Conscience Is Self-Eliminating gave him unawares? Sooner or later, Lack and others have found that such a consciously or subconsciously, he senses negative feedback demonstrably con- It is a mistake to think that we can that he has received two communica- trols the fecundity of birds (11). But control the breeding of mankind in the tions, and that they are contradictory: men are not birds, and have not acted long run by an appeal to conscience. (i) (intended communication) "If you like them for millenniums, at least. Charles Galton Darwin made this point don't do as we ask, we will openly con- If each human family were depen- when he spoke on the centennial of the demn you for not acting like a respon- dent only on its own resources; if the publication of his grandfather's great sible citizen"; (ii) (the unintended children of improvident parents starved book. The argument is straightforward communication) "If you do behave as to death; if, thus, overbreeding brought and Darwinian. we ask, we will secretly condemr. you its own "punishment" to the germ line- People vary. Confronted with appeals for a simpleton who can be shamed then there would be no public interest to limit breeding, some people will un- into standing aside while the rest of us in controlling the breeding of families. doubtedly respond to the plea more exploit the commons." But our society is deeply committed to than others. Those who have more Everyman then is caught in what the welfare state (12), and hence is children will produce a larger fraction Bateson has called a "double bind." confronted with another aspect of the of the next generation than those with Bateson and his co-workers have made tragedy of the commons. more susceptible consciences. The dif- a plausible case for viewing the double In a welfare state, how shall we deal ference will be accentuated, generation bind as an important causative factor in with the family, the religion, the race, by generation. the genesis of schizophrenia (17). The or the class (or indeed any distinguish- In C. G. Darwin's words: "It may double bind may not always be so able and cohesive group) that adopts well be that it would take hundreds of damaging, but it always endangers the overbreeding as a policy to secure its generations for the progenitive instinct mental health of anyone to whom it is own aggrandizement (13)? To couple to develop in this way, but if it should applied. "A bad conscience," said the concept of freedom to breed with do so, nature would have taken her Nietzsche, "is a kind of illness." the belief that everyone born has an revenge, and the variety Homo contra- To conjure up a conscience in others 1246 SCIENCE, VOL. 162  is tempting to anyone who wishes to If the word responsibility is to be coercion is not to say that we are re- extend his control beyond the legal used at all, I suggest that it be in the quired to enjoy it, or even to pretend limits. Leaders at the highest level sense Charles Frankel uses it (20). we enjoy it. Who enjoys taxes? We all succumb to this temptation. Has any "Responsibility," says this philosopher, grumble about them. But we accept President during the past generation "is the product of definite social ar- compulsory taxes because we recognize failed to call on labor unions to moder- rangements." Notice that Frankel calls that voluntary taxes would favor the ate voluntarily their demands for higher for social arrangements-not propa- conscienceless. We institute and (grum- wages, or to steel companies to honor ganda. blingly) support taxes and other coercive voluntary guidelines on prices? I can devices to escape the horror of the recall none. The rhetoric used on such commons. occasions is designed to produce feel- Mutual Coercion An alternative to the commons need ings of guilt in noncooperators. Mutually Agreed upon not be perfectly just to be preferable. For centuries it was assumed without With real estate and other material proof that guilt was a valuable, perhaps The social arrangements that produce goods, the alternative we have chosen even an indispensable, ingredient of the responsibility are arrangements that is the institution of private property civilized life. Now, in this post-Freudian create coercion, of some sort. Consid- coupled with legal inheritance. Is this world, we doubt it. er bank-robbing. The man who takes system perfectly just? As a genetically Paul Goodman speaks from the money from a bank acts as if the bank trained biologist I deny that it is. It modern point of view when he says: were a commons. How do we prevent seems to me that, if there are to be dif- "No good has ever come from feeling such action? Certainly not by trying to ferences in individual inheritance, legal guilty, neither intelligence, policy, nor control his behavior solely by a verbal possession should be perfectly cor- compassion. The guilty do not pay appeal to his sense of responsibility. related with biological inheritance-that Downloaded from http://science.sciencemag.org/ on July 8, 2020 attention to the object but only to them- Rather than rely on propaganda we those who are biologically more fit to selves, and not even to their own in- follow Frankel's lead and insist that a be the custodians of property and power terests, which might make sense, but to bank is not a commons; we seek the should legally inherit more. But genetic their anxieties" (18). definite social arrangements that will recombination continually makes a One does not have to be a profes- keep it from becoming a commons. mockery of the doctrine of "like father, sional psychiatrist to see the conse- That we thereby infringe on the free- like son" implicit in our laws of legal in- quences of anxiety. We in the Western dom of would-be robbers we neither heritance. An idiot can inherit millions, world are just emerging from a dreadful deny nor regret. and a trust fund can keep his estate two-centuries-long Dark Ages of Eros The morality of bank-robbing is intact. We must admit that our legal that was sustained partly by prohibi- particularly easy to understand because system of private property plus inheri- tion laws, but perhaps more effectively we accept complete prohibition of this tance is unjust-but we put up with it by the anxiety-generating mechanisms activity. We are willing to say "Thou because we are not convinced, at the of education. Alex Comfort has told the shalt not rob banks," without providing moment, that anyone has invented a story well in The Anxiety Makers (19); for exceptions. But temperance also can better system. The alternative of the it is not a pretty one. be created by coercion. Taxing is a good commons is too horrifying to contem- Since proof is difficult, we may even coercive device. To keep downtown plate. Injustice is preferable to total concede that the results of anxiety may shoppers temperate in their use of ruin. sometimes, from certain points of view, parking space we introduce parking It is one of the peculiarities of the be desirable. The larger question we meters for short periods, and traffic warfare between reform and the status should ask is whether, as a matter of fines for longer ones. We need not quo that it is thoughtlessly governed policy, we should ever encourage the actually forbid a citizen to park as long by a double standard. Whenever a re- use of a technique the tendency (if not as he wants to; we need merely make it form measure is proposed it is often the intention) of which is psycholog- increasingly expensive for him to do so. defeated when its opponents trium- ically pathogenic. We hear much talk Not prohibition, but carefully biased phantly discover a flaw in it. As Kings- these days of responsible parenthood; options are what we offer him. A Madi- ley Davis has pointed out (21), worship- the coupled words are incorporated son Avenue man might call this per- pers of the status quo sometimes imply into the titles of some organizations de- suasion; I prefer the greater candor of that no reform is possible without unan- voted to birth control. Some people the word coercion. imous agreement, an implication con- have proposed massive propaganda Coercion is a dirty word to most trary to historical fact. As nearly as I campaigns to instill responsibility into liberals now, but it need not forever be can make out, automatic rejection of the nation's (or the world's) breeders. so. As with the four-letter words, its proposed reforms is based on one of But what is the meaning of the word dirtiness can be cleansed away by ex- two unconscious assumptions: (i) that responsibility in this context? Is it not posure to the light, by saying it over and the status quo is perfect; or (ii) that the merely a synonym for the word con- over without apology or embarrassment. choice we face is between reform and science? When we use the word re- To many, the word coercion implies no action; if the proposed reform is sponsibility in the absence of substantial arbitrary decisions of distant and irre- imperfect, we presumably should take sanctions are we not trying to browbeat sponsible bureaucrats; but this is not a no action at all, while we wait for a a free man in a commons into acting necessary part of its meaning. The only perfect proposal. against his own interest? Responsibility kind of coercion I recommend is mutual But we can never do nothing. That is a verbal counterfeit for a substantial coercion, mutually agreed upon by the which we have done for thousands of quid pro quo. It is an attempt to get majority of the people affected. years is also action. It also produces something for nothing. To say that we mutually agree to evils. Once we are aware that the 13 DECEMBER 1968 1247 status quo is action, we can then com- government is paying out billions of sciences selects for the disappearance pare its discoverable advantages and dollars to create supersonic transport of all conscience in the long run, and disadvantages with the predicted ad- which will disturb 50,000 people for anin,crease in anxiety in the short. vantages and disadvantages of the pro- every one person who is whisked from The only way we can preserve and posed reform, discounting as best we coast to coast 3 hours faster. Adver- nurture other and more precious free- can for our lack of experience. On the tisers muddy the airwaves of radio and doms is by relinquishing the freedom basis of such a comparison, we can television and pollute the view of to breed, and that very soon. "Freedom make a rational decision which will not travelers. We are a long way from out- is the recognition of necessity"-and it involve the unworkable assumption that lawing the commons in matters of is the role of education to reveal to all only perfect systems are tolerable. pleasure. Is this because our Puritan the necessity of abandoning the free- inheritance makes us view pleasure as dom to breed. Only so, can we put an something of a sin, and pain (that is, end to this aspect of the tragedy of the Recognition of Necessity the pollution of advertising) as the sign commons. of virtue? Perhaps the simplest summary of this Every new enclosure of the com- analysis of man's population problems mons involves the infringement of References is this: the commons, if justifiable at somebody's personal liberty. Infringe- 1. J. B. Wiesner and H. F. York, Sci. Amer. 211 (No. 4), 27 (1964). all, is justifiable only under conditions ments made in the distant past are ac- 2. G. Hardin, J. Hered. 50, 68 (1959); S. von of low-population density. As the hu- cepted because no contemporary com- Hoernor, Science 137, 18 (1962). 3. J. von Neumann and 0. Morgenstern, Theory man population has increased, the plains of a loss. It is the newly pro- of Games and Economic Behavior (Princeton commons has had to be abandoned in posed infringements that we vigorously Univ. Press, Princeton, N.J., 1947), p. 11. 4. J. H. Fremlin, New Sci., No. 415 (1964), p. 285. one aspect after another. oppose; cries of "rights" and "freedom" 5. A. Smith, The Wealth of Nations (Modem Library, New York, 1937), p. 423. First we abandoned the commons in fill the air. But what does "freedom" 6. W. F. Lloyd, Two Lectures on the Checks to food gathering, enclosing farm land mean? When men mutually agreed to Downloaded from http://science.sciencemag.org/ on July 8, 2020 Population (Oxford Univ. Press, Oxford, Eng- land, 1833), reprinted (in part> in Population, and restricting pastures and hunting pass laws against robbing, mankind be- Evolution, and Birth Control, G. Hardin, and fishing areas. These restrictions came more free, not less so. Individuals Ed. (Freeman, San Francisco, 1964), p. 37. 7. A. N. Whitehead, Science and the Modern are still not complete throughout the locked into the logic of the commons World (Mentor, New York, 1948), p. 17. world. are free only to bring on universal ruin; 8. G. Hardin, Ed. Population, Evolution, and Birth Control (Freeman, San Francisco, 1964), Somewhat later we saw that the com- once they see the necessity of mutual p. 56. 9. S. McVay, Sci. Amer. 216 (No. 8>, 13 (1966). mons as a place for waste disposal coercion, they become free to pursue 10. J. Fletcher, Situation Ethics (Westminster, would also have to be abandoned. Re- other goals. I believe it was Hegel who Philadelphia, 1966). 11. D. Lack, The Natural Regulation of Animal strictions on the disposal of domestic said, "Freedom is the recognition of Nuimbers (Clarendon Press, Oxford, 1954). sewage are widely accepted in the necessity." 12. H. Girvetz, From Wealth to Welfare (Stan- ford Univ. Press, Stanford, Calif., 1950). Western world; we are still struggling The most important aspect of neces- 13. G. Hardin, Perspec. Biol. Med. 6, 366 (1963). 14. U. Thant, Int. Planned Parenthood News, No. to close the commons to pollution by sity that we must now recognize, is the 168 (February 1968>, p. 3. automobiles, factories, insecticide necessity of abandoning the commons 15. K. Davis, Science 158, 730 (1967). 16. S. Tax, Ed., Evolution after Darwin (Univ. sprayers, fertilizing operations, and in breeding. No technical solution can of Chicago Press, Chicago, 1960), vol. 2, p. atomic energy installations. rescue us from the misery of overpopu- 469. 17. G. Bateson, D. D. Jackson, J. Haley, J. Weak- In a still more embryonic state is our lation. Freedom to breed will bring land, Behav. Scd. 1, 251 (1956). recognition of the evils of the commons ruin to all. At the moment, to avoid 18. P. Goodman, New York Rev. Books 10(8), 22 (23 May 1968). in matters of pleasure. There is almost hard decisions many of us are tempted 19. A. Comfort, The Anxiety Makers (Nelson, London, 1967). no restriction on the propagation of to propagandize for conscience and 20. C. Frankel, The Case for Modern Man (Har- sound waves in the public medium. The responsible parenthood. The tempta- per, New York, 1955), p. 203. 21. J. D. Roslansky, Genetics and the Future of shopping public is assaulted with mind- tion must be resisted, because an ap- Man (Appleton-Century-Crofts, New York, less music, without its consent. Our peal to independently acting con- 1966), p. 177. 1248 SCIENCE, VOL. 162 The Tragedy of the Commons Garrett Hardin Science 162 (3859), 1243-1248. DOI: 10.1126/science.162.3859.1243 Downloaded from http://science.sciencemag.org/ on July 8, 2020 ARTICLE TOOLS http://science.sciencemag.org/content/162/3859/1243 REFERENCES This article cites 11 articles, 2 of which you can access for free http://science.sciencemag.org/content/162/3859/1243#BIBL PERMISSIONS http://www.sciencemag.org/help/reprints-and-permissions Use of this article is subject to the Terms of Service Science (print ISSN 0036-8075; online ISSN 1095-9203) is published by the American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. The title Science is a registered trademark of AAAS. Copyright © 1968 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.