Science in Christian Perspective



The Tragedy of the Commons*
Department of Biology University of California, Santa Barbara, California

From:PSCF 21 (September 1969): 83-87.

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 the 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.

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 weeddominance. 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.

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 extentthere 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 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.

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 he on the basis of merit, as defined by some agreed-upon standards. It might be by lottery. Or it might be on a firstcome, 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.

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.2 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.

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 he a matter of public concern. Parents who bred too exuberantly would leave fewer descendants, not more, because they would he unable to care adequately for their children. David Lack and others have found that such a negative feedback demonstrably controls the fecundity of birds3. 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 linethen there would be no public interest in controlling the breeding of families. But our society is deeply committed to the welfare state4, 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,'? 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.

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....

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 lowpopulation 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 airways 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.


1S. McVay, Sc. Amer. 216 (No. 8), 13 (1966).
2J. Fletcher, Situation Ethics (Westminster), Philadelphia, 1966).
3D. Lack, The Natural Regulation of Animal Numbers (Claren don Press, Oxford, 1954).
4J-J, Girvetz, From Wealth to Welfare (Stanford Univ. Press, Stanford, Calif., 1950).
5G. Hardin, Perspec. Biol. Med. & Med. 6, 366 (1963).

**This article is a collection of partial selections from the paper with this title published in Science 162, 1243 (1968), copyright 1968 by the American Association for the Advancement of Science.


Wilbur L. Bullock
Department of Zoology University of New Hampshire Durham, New Hampshire 03824

Many of our colleagues, particularly those in academic teaching and research, are viewing the prospects for the future of mankind with growing alarm. Often they sound like "prophets of doom" that make the predictions of the apocalypse sound all too real and imminent. Barry Commoner1 warns of the far-reaching and catastrophic effects of thermonuclear war and environmental pollution. The Paddock brothers2 tell us that we are now entering the "Age of Famine". Paul Ehrlich3 announces that the battle against overpopulation and famine is already lost and that we must prepare to salvage what is left after catastrophe decimates the human race. Harold Cassidy4 and Lamont Cole5 agree with these grim predictions and provide additional evidence that mankind is rapidly moving toward a day of reckoning. Cassidy talks about "Incipient Environmental Collapse" and Cole asks: "Can the World he Saved?" These are but a few of the grim prognostications voiced by many of our more vocal and concerned associates. Many who have neither taken up the pen nor hit the lecture trail would add to the growing clamor of alarm for the immediate future of man.

Two men who have presented analyses of the human dilemma are Lynn White6 and Garrett Hardin7. White, an historian, has attempted to determine the historic basis for the problem. Hardin, a biologist, suggests what he considers to be the inevitable outcome of the population crisis in terms of political necessity. The conclusions of both men have serious Christian implications.

The Historic Roots of our Ecologic Crisis

White blames "orthodox Christian arrogance" for most of our environmental problems. He reasons that God gave man dominion over the earth, man used this dominion to exploit and pollute and, therefore, we arrive at the mess in which we now find ourselves. As evangelical Christians we may not like the sound of that reasoning but an honest analysis of human history provides too much support for White's logic. It is futile to attempt, in the name of "orthodox" or "conservative" Christianity, to deny that there is much uncomfortable truth in the charge. The most serious weakness I see in White's position is that it lumps too much into the one pot of "orthodox Christianity". He fails to recognize that probably the greatest exploitation was done by people who had only the vaguest, most perfunctory association with any form of Christianity. Furthermore, these exploiters were interested in their own selfish gain, a motive distinctly contrary to the self-denial of true Christian love. Unfortunately, we must admit that even real, fervent Christians have sometimes been guilty as well. In short, we have another example of the old problem of confusing -and we all do it-the ideal toward which we strive and the faltering, pathetically imperfect level of actual performance. There seems to be little question, however, that God's command to rule the earth has been the sine quo non of most scientific research and its technological application. Far eastern and other nature religions seem to inhibit, through pantheistic worship of nature or through actual fear of natural phenomena, scientific and technological endeavors. The biblical picture of man, as but "little lower than the angels" and the supervisor of the earth that God created, is much more conducive to inquiry and mastery than religious reverence of all life because of belief in re-incarnation or other intimate mystical association of man and the rest of nature.

However, the misuse of a God-given gift by the recipient does not in itself condemn either the gift or the giver. That some people use television to deaden or corrupt their minds does not mean that television is all evil. To the Christian, the exalted position of man in nature is a basic concept in our understanding of both God and man. This might sound like "arrogance," but if we are so charged, we must admit the charge. On the other hand, the Christian must be the first to recognize, again on the basis of the biblical picture of man, that sinful man-ourselves included-all too often acts as the despoiler of nature and all too seldom as the reverent, responsible conserver and steward.

White recommends St. Francis as a kind of a compromise between orthodox Christianity and the pantheistic nature religions. It might be well to study this suggestion carefully to see just what aspects of St. Francis were compatible with biblical Christianity. I have little doubt but that we would benefit from such a study. It would certainly bring into focus some aspects of twentieth century, western culture that we have all to glibly accepted as "Christian" but which are badly tarnished with selfishness, materialism, and "the love of money".

White oversimplifies the problem by ignoring the variety of reactions, in different groups of Christians, to the divine command to rule the earth. However, my own reflections on White over the past two years lead me to conclude that, unpleasant though his conclusions are, Christians must accept a considerable measure of guilt to the charge of abusing and exploiting our Godgiven domain. This divinely ordained authority is a much more awesome thing than we have realized. It is basic to the Christian faith, but we must admit that we have seriously neglected it. And, others have made matters worse by accepting the gift with no thought of the Giver nor of their own responsibility to their fellow man.

The Tragedy of the Commons

Hardin's consideration of the population problem is based on the assumption that the population explosion is one of a class of problems (along with national security in a nuclear world) for which no technical solution is possible. Such an assumption is highly unorthodox in a generation in which there has been on question but that, given enough time and money, the human mind could conquer all problems. Actually, the significant difference between the optimists and the pessimists about the future of man is on precisely this point. The optimists focus on the significant progress of research in fertility control and in food production and then talk of the future in glowing terms. The pessimists are convinced that we cannot pull technological rabbits out of the hat fast enough to avert catastrophe. To all of us, trained in the years of research affluence, it comes as a shock to he told that NSF or NIH projects might not be able to solve all problems of technology, health, and survival. As Christians, however, we should have realized long ago that sinful man, alienated from God, is unable to solve the really basic problems of human existence and even survival. It should be no surprise to us that there are problems that defy technological solution and which require a drastic change in human moral and ethical structures in order that man might survive. We should have recognized long ago that even our most dramatic successes-such as, the manipulation of atomic energy or the control of human genetic mechanisms-have moral and spiritual implications of the gravest nature.

It should be no surprise to us that there are problems that defy technological solution and which require a drastic change in human moral and ethical structures in order that man might survive.

Hardin tells us that, in the face of the population problem, "freedom to breed is intolerable". Furthermore, we need to agree to a "mutual coercion" to limit human births. "The only way we can preserve and nurture other and more precious freedoms is by relinquishing the freedom to breed, and that very soon."

The freedom to breed, to have and to raise children, has been one of mankind's most cherished possessions. Indeed for many people in this world it has often been the only freedom they have had. Now we have reached the point in human history where uninhibited breeding is threatening the very existence of mankind. Even the most zealous supporter of the biblical directive to "be fruitful and multiply and replenish the earth" must realize that the earth has been replenished for some time. The continued, unrestricted participation in the "commons" of human reproduction can only bring disaster. To refuse to restrict, by incentive or by edict, the natural propensity to breed, will inevitably and quickly lead to world-wide famine, to disease epidemics, to unrest, and to war. To force or to encourage people to "let nature take its course" in the name of sentiment or theology will certainly result in millions of horrible, unpleasant deaths from starvation, disease, and violence. It seems clear to me that the advocates of this "freedom" or this "responsibility" will be guilty of mass murder, and that before many years have passed.

Hardin has described his solution in forceful but non-specific terms. Ehrlich3 has spelled out some of the details. He suggests: paying people for not having children and/or penalizing them when they do; sterility capsules for all women, capsules that can be removed under carefully controlled conditions; and the introduction of sterilizing chemicals into food and water with antidotes being allowed as a special privilege. We are certainly faced with some sweeping and unconventional proposals. What are Christians to think and do about all of this?
Our first task is to decide if there really is a problem that requires such drastic solutions. My own study of the problem over the past few years has convinced me that there is little basis for optimism. Even if Hardin is wrong in his assumption that no technological solutions are possible, I see little likelihood that such solutions will actually be forthcoming. The growing unrest throughout the world, the lack of concern by affluent Americans (including Christians), the shift toward irrationalism and anti-intellectualism even in educational institutions, all tend to guarantee that any achievements will be far too little and far too late, Therefore, I have been forced to conclude that the problem is real, and that only the most drastic solutions could possibly work. However, I find that I cannot, at this time, comfortably accept the morality of the proposed solutions. Rather, I am inclined to accept such catastrophe as inevitable. Restrictive laws, if instituted must be obeyed because the morality of disobedience to such laws seems clearly worse than the alternative of not having such laws. I cannot, however, bring myself to enthusiastically promote such laws.

In a more positive and constructive vein, I feel that, as in the New Testament church, we need to become more concerned with serving the individual needy people with whom God brings us into contact. Awareness of approaching catastrophe should constantly haunt us to he more zealous in this task. And, if we view such catastrophe in terms of divine judgment on a rebellions world, we are even more obligated to be more active in "doing good". After all, are we not urged to "encourage one another, all the more since you see the Day of the Lord is coming near"? Such an attitude is far better than the sometimes comfortable "involvement" in the grandiose problems of all mankind or all the poor people. It requires the much more demanding, personal involvement with individuals in our everyday lives. It seems to me that this is the kind of involvement seen in the New Testament church and in the earthly ministry of our Lord Jesus Christ.

In short, it seems to me that the situation is far too serious for us to he satisfied with picking apart the theological flaws of White and Hardin or others with similar views and concern. They are trying to tell us something of cataclysmic proportions, something that is not too different from the biblical apocalypse.

If there ever was a time for the church of Jesus Christ to be about the Father's business, this is it.


1Commoner, Barry (1966) Science and Survival. Viking, New York.
2Paddock, William and Paddock, Paul (1967) Famine-1975!
America's Decision: Who Will Survive
. Little, Brown, Boston. 
3Ehrlich, Paul II. (1969) "Population, Fond and Environment: Is the battle lost?" The Biologist 51: 8-19.
4Cassidy, Harold C. (1967) "On Incipient Environmental Collapse," BioScience 17: 878-882.
5Cnlc, LaMont C. (1968) "Can the World be Saved?" BioScience 18: 679-693. 
6White, Lynn, Jr. (1967) "The Historic Roots of our Ecologic Crisis." Science 155: 1203-1207. See also Journal ASA 21, 42 (1969), 
7Hardin, Carrett (1968) "The Tragedy of the Commons." Science 162: 1243-1248.