Science 13 December 1968: 

Vol. 162. no. 3859, pp. 1243 - 1248 

DOI: 10.1126/science.162.3859.1243 

http://www.sciencemag.org/cgi/content/full/162/3859/1243 

Articles 

The Tragedy of the Commons 

Garrett Hardin 

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

morality.

The author is professor of biology, University of California, Santa Barbara. This article is based 

on a presidential address presented before the meeting of the Pacific Division of the American 

Association for the Advancement of Science at Utah State University, Logan, 25 June 1968. 

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 solutionsin 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 technicalsolution 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 

technicalsolution. 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 problemwas 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 overthe head; or I can drug 

him; or I can falsify the records. Every way in which I "win" involves, in some sense, an 

abandonment ofthe 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 privilegesthey now enjoy. They think that farming the seas or 

developing new strains of wheat will solve the problem--technologically. Itry 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 nextfew 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 isstill 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 provesthat 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 willsoon 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, asit 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 oflaissez-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 

generatestragedy. 

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 fromthe 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 naturalselection 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 requiresthat 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 offish 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. 

Pollution 
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 dangerousfumes 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 lessthan 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 

metropolisis 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 

importantsense 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 ancientChinese; 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 . . ." isthe 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 detailsto 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 indicatesthat 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 fortheir 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):
The Universal Declaration of Human Rights describes the family as the natural and fundamental 

unit of society. It followsthat any choice and decision with regard to the size of the family must 

irrevocably rest with the family itself, and cannot be made by anyone else. 

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 ofthe 

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 whetherthe 

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 sensesthat 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 companiesto 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 substantialsanctions are we not trying to browbeat a free man in 

a commonsinto 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'slead 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 wouldbe 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 forshort 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 fourletter 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 seemsto 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 sometimesimply 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, isjustifiable 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 dollarsto create supersonic transport which will disturb 50,000 people for 

every one person who is whisked from coast to coast 3 hoursfaster. 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 isthe 

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. 

REFERENCES 

1. J. B. Wiesner and H. F. York, Sci. Amer. 211 (No. 4), 27 (1964). 

2. G. Hardin, J. Hered. 50, 68 (1959) ; S. von Hoernor, Science 137, 18 (1962) .

3. J. von Neumann and 0. Morgenstern, Theory of Games and Economic Behavior 

(Princeton Univ. Press, Princeton, N.J., 1947), p.11. 

4. J. H. Fremlin, New Sci., No. 415 (1964), p. 285. 

5. A. Smith, The Wealth of Nations (Modern Library, New York, 1937), p. 423. 

6. W. F. Lloyd, Two Lectures on the Checks to Population (Oxford Univ. Press, Oxford, 

England, 1833), reprinted (in part)in Population, Evolution, and Birth Control, 

G. Hardin, Ed. (Freeman, San Francisco, 1964), p. 37. 

7. A. N. Whitehead, Science and the Modern World (Mentor, New York, 1948), p. 17. 

8. G. Hardin, Ed. Population, Evolution, and Birth Control (Freeman, San Francisco, 1964), 

p. 56.

9. S. McVay, Sci. Amer. 216 (No. 8), 13 (1966). 

10. J. Fletcher, Situation Ethics (Westminster, Philadelphia, 1966). 

11. D. Lack, The Natural Regulation of Animal Numbers (Clarendon Press, Oxford, 1954).

12. H. Girvetz, From Wealth to Welfare (Stanford Univ. Press, Stanford, Calif., 1950).

13. G. Hardin, Perspec. Biol. Med. 6, 366 (1963). 

14. U. Thant, Int. Planned Parenthood News, No. 168 (February 1968), p. 3. 

15. K. Davis, Science 158, 730 (1967) .

16. S. Tax, Ed., Evolution after Darwin (Univ. of Chicago Press, Chicago, 1960), vol. 2, p. 

469.

17. G. Bateson, D. D. Jackson, J. Haley, J. Weakland, Behav. Sci. 1, 251 (1956) .

18. P. Goodman, New York Rev. Books 10(8), 22 (23 May 1968). 
19. A. Comfort, The Anxiety Makers (Nelson, London, 1967). 

20. C. Frankel, The Case for Modern Man (Harper, New York, 1955), p. 203. 

21. J. D. Roslansky, Genetics and the Future of Man (Appleton-Century-Crofts, New York, 

1966), p. 177.