The legitimate object of government is to do for a community of people whatever they need to have done but can not do at all or can not do well for themselves in their separate or individual capacities.
— Abraham Lincoln
It is written that when Rabbi Hillel (a contemporary of Jesus of Nazareth) was asked to recite the essence of The Law of Moses while standing on one foot, he replied: “What is hateful to thyself do not do to another. That is the whole Law, the rest is Commentary.”
After several decades of studying, publishing and teaching moral philosophy, I believe that I can identify the foundation of morality in a single breath: “Morality is a plus-sum game.”
These precepts are not contrary, for they are of differing logical orders. Hillel’s precept is a moral commandment –” an ethical rule of conduct. On the other hand, “morality is a plus-sum game” is an account of the foundation of morality; what philosophers call “meta-ethics.”
So just what is the meaning of “morality is a plus-sum game?” While it is easy enough to articulate this question, spelling out an answer might require volumes of elaboration, as indeed it has. But here, at least, are a few initial steps. 
The late American philosopher, John Rawls, explained this principle with admirable clarity when he wrote: "[A] society is a cooperative venture for mutual advantage… [S]ocial cooperation makes possible a better life for all than any would have if each were to live solely by his own efforts." (A Theory of Justice, p. 4).
This insight is by no means original with Rawls. It resounds throughout the history of philosophy and political theory. Moreover, it is proven time and again in the experience of successful civilizations and, conversely, in the decline and fall of other civilizations.
Accordingly, this proven insight clearly explains why a radically individualistic political dogma such as libertarianism is not only immoral, it is empirically unworkable. Any society based upon such a dogma is bound to fail to satisfy the legitimate needs of its citizens.
About Game Theory:
Game theory, which was developed by John von Neuman and Oskar Morgenstern in the forties, “attempts to mathematically capture behavior in strategic situations, in which an individual’s success in making choices depends upon the choices of others.” (Wikipedia) (John Nash, portrayed in the movie, “A Beautiful Mind,” won his Nobel Prize in economics for his work in game theory). While game theory can involves some highly advanced mathematical elaborations, the essentials can be readily understood by the ordinary citizen. 
In its most general sense, a “game” is a cooperative, rule-governed and goal-directed activity.
With the rare exception of solitaire, games involve multiple “players:” two individuals (e.g., tennis and chess), two teams (e.g. football), several individuals or teams (e.g. lotteries, tournaments), and entire societies (e.g., governments, morality). If there are two players or teams and the game is designed to result in one winner and one loser, it is called a “zero sum game.” Tennis and chess are zero sum games. If there are multiple players and only one winner, the game designated as “minus sum.” Lotteries and tennis tournaments are minus sum games. Competitive games are either zero-sum or minus-sum. Such games are also “cooperative” in the sense that the players agree to obey the rules.
However, there are other “cooperative, rule-governed, goal oriented” activities in which the players cooperate to produce positive results, i.e. “wins,” for all players. While such activities are generally not called games, they nonetheless fit the definition: “cooperative, rule-governed and goal oriented.”
For example, from the point of view of the teams and the spectators, football is a zero sum game: one team wins and the other loses. But from the point of view of the participating players, it is a plus-sum game: each player interacts with the other team members in a well-coordinated activity which, when well-executed, results in a gain for all the team players that none can accomplish alone, namely, a win.
A freely consummated barter or purchase is a plus-sum game –” cooperative, rule governed and goal oriented –” in that each participant gains through the transaction. If I have more vehicles than I want and my house is in need of repair, and if my neighbor, a skilled carpenter, needs a car, then a trade of my car for his labor leaves us both better off. For a sale to take place, both the buyer and the seller must perceive a personal advantage in the transaction. Not surprisingly, game theory has attracted the intense interest of economists.
Science is a plus-sum game. It is cooperative: an accumulated accomplishment of millions of working scientists through the centuries. It is rule-governed: following strict rules of inference and evidence, and requirements of publicity, replicability and falsifiability. And it is oriented toward the goal of establishing verifiable truth.
A well-ordered society is also a plus-sum game, whereby capital, labor, education and government function cooperatively according to mutually acknowledged and enforceable rules (i.e., laws and regulations) in pursuit of common goals. These common goals are clearly articulated in the Preamble to the United States Constitution: justice, domestic tranquility, common defense, general welfare, and “the blessings of liberty.”
Each institutional “player” in a successful “plus-sum game” of a just economic/political order needs the cooperative efforts of the other players if that society is to accomplish, in John Rawls’s words, “a better life for all than any would have if each were to live solely by his own efforts.”
In contrast, a libertarian (unregulated “free market”) economy is minus-sum game in the extreme: few winners, a great many losers. As we are discovering in the United States today.
Many non-competitive sporting activities are also plus-sum games, including mountain climbing, sailing, and tandem (two person) canoeing, all of which require well coordinated “team play” to achieve a well-defined goal.
A personal example: I am a life-long aficionado of white-water boating (in kayaks and canoes). Well before I acquired much experience and skill in this sport, I persuaded my brother to run a swift Utah river with me in his new canoe. Each of us had independent ideas as to how to maneuver the thing. In short, two captains and no crew. Rock straight ahead? Bow wants to go right, and stern wants to go left. It was a near disaster. As any tandem canoeist will tell you, a successful river run (a plus sum) can only be accomplished with an ability to “read the water” and to execute coordinated paddle strokes according to unambiguous decisions by the designated “captain.” Similarly with successful team climbs and sailing cruises.
The Virtues as Plus-Sum:
Time now to assess my contention that a moral order in society is a plus sum game. Consider the usual roster of moral virtues: honesty, trustworthiness, courage, compassion, charity, loyalty and, perhaps most fundamentally, empathy –” the capacity to share another’s joy and to feel another’s pain. Is it not abundantly obvious that the more virtuous the members of a society, the greater the plus-sum “payoffs” of social life? Economic transactions would be conducted with full knowledge and confidence, with no “inefficient” losses due to default, deceptive advertising, or fraudulent contracts. Marriages would be secure and enduring. Government officials could be expected to serve their constituents, free of bribery and corruption. In a community of optimally trustworthy, compassionate, tolerant and generous individuals, there would be no need to invest community resources in police, criminal courts and prisons.
Such a consideration led James Madison to conclude that “if men were angels, no government would be necessary.” (The Federalist, 51). Regarding the codification and enforcement of criminal law, Madison was no doubt correct. Even so, his pronouncement is an overstatement, for even in a society of angels, some government would be necessary. For example, there would have to be traffic laws, no matter how virtuous the drivers, if traffic were to move safely and efficiently. Once the traffic lights fail, the freedom to move is obliterated in the resulting chaos. In general, if a game is to be played successfully –” including the “game” of economic/political activity –” the players must know the rules, even if there is total assurance that no one will cheat and thus there is no need whatever to enforce the rules with the threat of penalties.
There are, to be sure, some traditional “virtues” that contribute little to the mutual advantages of community life. David Hume called these “the monkish virtues,” and they include celibacy, fasting, penance, mortification, self-denial, silence and solitude. Of these, Hume observed: “they serve to no manner of purpose; neither advance a man’s fortune in the world, nor render him a more valuable member of society…” (Enquiry Concerning Morals, IX:1) With Hume, I conclude that these traits scarcely qualify a “virtues” at all, but rather are the consequences of “superstition and false religion.”
The Vices as Minus-Sum:
In contrast, moral vices subvert and stifle the mutual advantages of social life, which, I contend, is precisely why they are vices. Foremost among these are pride, cruelty, ruthlessness, hatred, prejudice, dishonesty, selfishness, greed. Add to these “an absence of empathy” which, as I have argued elsewhere, may be the most fundamental of the vices.
Each of these vices shred the fabric of an orderly society, as they make cooperation impossible or even counter-productive, as they undermine rules, and as they subvert the pursuit of common goals. In a society of liars, contracts can not be made. When prejudice and hatred prevail, all citizens can not be equal before the law. A representative republic can not endure if public officials can not be trusted. And an ideology that prizes selfishness and greed cannot be the foundation of a flourishing economic/political system.
The Inevitable Failure of
Libertarianism as a Social Theory:
I most emphatically do not wish to suggest that libertarians are wicked people. Many libertarians that I know personally, and others that I know by reputation, are as tolerant, unbiased, generous and charitable as any liberal, and even more so than some liberals of my acquaintance. Some libertarians are so tolerant that they invite me and other liberals to publish in their journals and participate in their conferences.
However, as libertarians, they believe that the promotion of these virtues is no business of the government. Charity and tolerance, they insist, are and must remain, private virtues. To the libertarian, a voluntary contribution to the poor or to a school, museum or park is morally commendable. But taxation in support of welfare, education, museums and parks is theft. As for cruelty, ruthlessness and dishonesty, these vices are regarded by the libertarians as self-defeating and, when exposed in practice, these vices fail in a free market and in the unregulated association of free individuals. Any vices that constrain the fundamental “negative” rights life, liberty and property, can legitimately be sanctioned and punished by the “minimalist” libertarian government.
Even so, despite any private virtues of individual libertarians, as a public political philosophy libertarianism is morally inadequate. In practice, it will produce minus-sum consequences.
Consider once again, our criteria of a plus-sum game: a cooperative, rule-governed, goal directed activity aimed toward accomplishing mutual advantage.
Libertarian doctrine drops the cooperation criterion of gamesmanship in favor of “YOYO” –” "you’re on your own." The libertarian dogma of “the invisible hand” decrees that a collection of self-serving individuals seeking only to maximize their own personal freedom and wealth, will somehow, by “spontaneous generation,” evolve into an optimum social arrangement. No explicit rules and regulations are required apart from those laws designed to achieve the goal of the protection of the lives, liberties and property of each individual.
It is a neat and simple belief system which, unfortunately, neither history nor practical experience will validate. Instead, history has taught us that when a society officially embraces what Ayn Rand calls “the virtue of selfishness” and greed becomes the controlling force in community life, wealth and power do not “trickle down” to the masses, they “percolate up” to those in control, leaving those masses impoverished and disenfranchised. Government, having been “drowned in a bathtub,” offers no relief to the oppressed. “The free market” and “competitive enterprise,” extolled by the libertarians in theory, are set aside in practice. The prevailing capitalists regard competition as inefficient and inconvenient, and still worse, the constant competitive pressure to improve and innovate erodes profits. Hence mergers and acquisitions. Say goodbye to Mom and Pop stores and Downtown, USA. Say hello to Wall-Mart, Costco and Home Depot. Say goodbye to a free and diverse media. Say hello to the new “Ministry of Truth:” six media mega-corporations in control of 80% of the nation’s media, spewing out the official doctrines of “the free market” and “government is the problem.”
How, then, are diversity, free markets and competition to be preserved? How else than through the intervention of anti-trust laws, which means an activist government, which, of course, is anathema to the libertarian.
The eventual result? “Life, liberty and property” for the privileged few, with poverty and servitude for all the rest. A minus-sum game.
“You are on your own” does not work with tandem canoeing, nor with a social order. Without cooperative effort, without commonly acknowledged rules sanctioned and enforced by law, and without shared goals, a society cannot succeed.
Liberty and Autonomy in a Plus-Sum Society.
“What you are describing,” replies the libertarian, “is the ‘order’ of bee hive or of an ant colony. Pure communism. Not a place where I would want to live. How can personal liberty and autonomy thrive in your ‘cooperative venture for mutual advantage’?”
A wise answer was told to me by a Russian friend, a professor at Moscow University, during the “cowboy capitalism” days following the collapse of Soviet communism. “Under communism,” she observed, “we had order without freedom. Then we had freedom without order, only to discover that without order, there is no freedom.”
The libertarian and the liberal concur in their desire to maximize personal liberty. However, the libertarian advocates freedom without order –” without, that is, an institutional structure that will ensure freedom for all. Absent such a structure, liberty, like wealth, will “percolate up” to those in charge, “with liberty for some," leaving the masses with nothing but their squalor and oppression.
The liberal, on the other hand, strives to establish and maintain the social, economic and political order without which there is no freedom. The liberal understands that the economic output and the civil liberties of a society are the products of the joint contributions of all members of society –” of the plus-sum cooperative, rule governed and goal oriented efforts of all. Because no social order operates without some “friction,” there are inevitably victims of social and economic misfortune: the unemployed, the bankrupt, the abandoned. Add to these, the victims of natural misfortunes –” accidents, disease, birth defects, earthquakes, hurricanes, tornados, etc.
Voluntary charity to these unfortunates, as advocated by the libertarians, is commendable. But it is insufficient. Good for the souls of the charitable, but not very helpful to those in need. There are just too many of them. Moreover, voluntary charity is a “tax on virtue,” as are private donations to education, museums, libraries, concerts and parks. Most citizens correctly reflect, “I might contribute, but even if I do, my one contribution will not abolish poverty and ignorance, nor will it add significantly to civic excellence.” To accomplish these common benefits, all must contribute through taxes. And with this understanding, most enlightened citizens will pay their taxes willingly, as they likewise support legislation designed to relieve suffering and to promote the common good.
"Taxes," wrote Judge Oliver Wendell Holmes, "are the price we pay for civilization" — the very civilization that is prerequisite to any and all personal wealth. Accordingly, it is not unjust to require the beneficiaries of civilization to share in the burden of its maintenance. However, there may be justifiable reasons to complain about the distribution of this burden.
“Necessitous men are not free men,” FDR observed in 1936. The liberal realizes, as the libertarian does not, that if personal liberty is to be maximized in society, it is not enough merely to guarantee the life, liberty and property of each individual.
The social contract of a just community also requires that if the citizens are to enjoy “the blessings of liberty,” the pre-conditions of liberty must be attended to: namely, public education, economic opportunity, equal opportunity, the protection of common resources, and the promotion of civic institutions.
As the English conservative, Edmund Burke observed:
“[Society is] a partnership in every virtue and in all perfection. As the ends of such a partnership cannot be obtained in many generations, it becomes a partnership not only between those who are living, but between those who are living, those who are dead and those who are to be born.
Note:. For more about game theory and the "plus-sum" nature of a just society, see Chapter 5 ("Good for Each, Bad for All" ) and Chapter 6 ("The Moral Point of View") of my book in progress, Conscience of a Progressive.