Loyola of Los Angeles Law Review

November, 2001

Symposium

Intergenerational Equity

*163 TO OUR CHILDREN'S CHILDREN'S CHILDREN: THE PROBLEMS OF

INTERGENERATIONAL ETHICS

Lawrence B. Solum [FNa1]

B. Solum

I. Introduction

This essay serves as the introduction to the Loyola of Los Angeles Law Review's symposium on intergenerational justice. The importance of this topic cannot be overstated. Intergenerational ethics bears on questions of environmental policy, [FN1] health policy, [FN2] intellectual property law, [FN3] international development policy, [FN4] social security policy, [FN5] telecommunications policy, [FN6] and a variety of other issues.

*164 Part II. Clarifying the Problems of Intergenerational Ethics, is a first sketch of the scope and nature of intergenerational justice, introducing a variety of cases and contexts in which issues of intergenerational ethics arise and distinguishing between the political and moral dimensions of these issues. Part III. Theories of Distributive Justice, examines three approaches to intergenerational distributive justice: an egalitarian approach, a libertarian approach, and a utilitarian approach. Part IV. Methods of Justification, examines three strategies for justifying a theory of intergenerational justice: a social contract, the original position, and reflective equilibrium. Part V. A Word About the Relationship of Ethical and Moral Theory to Political Morality and Distributive Justice, marks a transition from questions of political philosophy to the more general realm of ethical and moral theory, examining utilitarianism as a comprehensive moral doctrine as well as deontological moral theory and contrasting these moral theories with a virtue-centered approach. Part VI. Some Conundrums of Intergenerational Ethics, examines three very general problems that a theory of intergenerational ethics must face: the problem of uncertainty, the problem of discount rates, and the problem of possible persons. Part VII. The Symposium, introduces the three contributions to the symposium, briefly situating each in relation to the general framework introduced in the previous parts. Finally, Part VIII. Toward a New Discourse of Intergenerational Ethics, draws some lessons for further work on the difficult problems of justice and morality across generations.

II. Clarifying the Problems of Intergenerational Ethics

The problems of intergenerational ethics are notoriously some of the most difficult in moral and political philosophy. There are many reasons why this is so, but before we begin to explore the thickets of argument that surround these problems, we ought to seek as much clarity as we can about what the problems really concern. One way to begin is to make the problems concrete. Another is to define some terms. Let us begin with the examples and then work on the definitions.

*165 A. Scenarios: Concrete Examples of the Problems of Intergenerational Ethics

Consider the following situations, contexts, or examples, each of which raises, in some sense, a problem of ethics, morality, or justice between the generations. Although each example is based loosely on a real world problem of intergenerational ethics, I am making a variety of simplifying assumptions and my description of the examples should not be read as entailing claims about the corresponding real world problems. Each example or context is given a name for ease of reference.

Case One: Care and Feeding. The most familiar context in which questions of duty between one generation and another arise is that of parents' duties to care for their children. Almost everyone agrees that such a duty exists as a matter of morality or ethics, and the law recognizes such a duty. Although exceptional circumstances can create special problems, [FN7] care and feeding is for the most part an easy case.

Case Two: Nursing the Elderly. The first example, care and feeding, involves the moral duties of parents to their children. The obvious corollary is the duty that children may have to care for their elderly parents. Although there is general agreement that children should care for their elderly parents, there is considerable disagreement about the extent and form of that duty. Do children have a duty to take elderly parents into the children's home? How great a share of the child's resources ought to be devoted to care for the elderly? Should this be a social responsibility rather than an individual one? These are all questions of intergenerational ethics.

Case Three: Social Security. Suppose that the "Baby Boomer" generation is numerically substantially larger than two succeeding generations called "Generation X" and "Generation Y." If Social Security is financed by having each generation that is *166 currently working pay for the social security benefits of the generation that has retired, then members of Generation X and Generation Y will be required to pay a substantially greater share of current income for the social security benefits of the Baby Boomers than the Baby Boomers paid for the social security benefits of their parents and grandparents. Such a situation would raise questions of distributive justice: is it fair for one generation to bear a larger burden than another?

Case Four: Legacies and Bequests. Another familiar context is that of intergenerational wealth transfers. Do parents have a duty to save during their lifetimes and transfer some of this wealth to their children or other descendents? Again there may be special cases, [FN8] but the ordinary understanding is that bequests and legacies are gifts, and that parents do not have a duty to save for such bequests or to leave money to their children. In the usual case, parents may wish to leave such a bequest and we count such a wish as virtuous. As a matter of distributive justice, however, it might be argued that intergenerational wealth transfers are unjust, insofar as they operate to perpetuate inequalities of wealth and income.

Case Five: Entailed Estates. The law may make it possible for parents to ensure that their children and their children's children's children receive a roughly equal share of the parents' wealth. The classic device in English law for achieving this goal was the entailed estate, [FN9] and the law sought to prevent the achievement of this end with the rule against perpetuities. [FN10] The notion that one had a duty to preserve wealth for distant generations once held great currency, but today this is generally thought to be a bad idea, absent special circumstances.

Case Six: Disastrous Global Warming. The prior five cases involve contexts in which future contingencies can, for the most *167 part, be reckoned and calculated. [FN11] The progress of science has, ironically, created an awareness of risks to future generations that may not easily be reduced to calculable probabilities of quantifiable harms. Global warming might be such a case. [FN12] Assume for the purposes of this article that consumption of greenhouse gases by the current generation poses an unquantifiable risk of global environmental catastrophe for our children's children's children (where that phrase is taken to mean our descendents who will be alive at a time when we are all dead). What duty do we owe them? How much of our welfare ought to be sacrificed for a nonquantifiable chance of an improvement in theirs?

Case Seven: Persistent Plutonium. Imagine that use of a very clean, very efficient plutonium-based nuclear fission reactor will pay very substantial economic and environmental dividends for the generation or two in which the reactor is in service (say a total economic savings of $100,000,000 and health benefit equivalent to saving 100 lives per plant). [FN13] Imagine further that containment of plutonium is not perfect, that, if released into the environment, even miniscule quantities of plutonium can cause cancers, and that plutonium persists in the environment for a very long time. Assume that each reactor will also cause one cancer death every 20 years for a period of 500,000 years (for a total of 25,000 deaths and associated economic costs of $2,500,000,000). Unlike global warming, I shall assume that persistent plutonium involves calculable risks and quantifiable consequences.

Case Eight: Reparations for Slavery. Suppose that one group in a past generation had enslaved a group of persons whose *168 descendents are identifiable. Does the current generation of persons who are not descendents of slaves owe the current generation of persons who are descendents of slaves compensation? This case of intergenerational ethics is different from the others, for two reasons. First, it is backward looking (ethical duties arising from past generations), and second, it involves relationships between members of the same generation (current descendents and nondescendents of slaves).

Case Nine: Economic Development. Each generation is faced with questions about how much to consume versus how much to invest. If the current generation consumed everything and invested nothing (in the form of capital equipment, technological innovations, and so forth), then the next generation would be no better off (or perhaps worse off) than the current one. If, however, the current generation forwent all unnecessary consumption and invested as much as possible in ways that would improve the lot of the next generation, then the next generation would presumably be much better off. The case of economic development simply refers to this tradeoff between consumption and investment.

Case Ten: Population Policy. Assume that an imaginary nation can adopt one of two population policies. The pro-growth policy will produce a much larger total population in 100 years, but that the average standard of living for that population will be relatively low. The population control policy will produce a much smaller total population in 100 years, but the average standard of living for that population will be relatively high. Of course, the choice between the two policies will determine whether potential future persons are ever born.

Our exploration of the problems of intergenerational ethics will occasionally refer back to these cases (care and feeding, nursing the elderly, social security, legacies and bequests, entailed estates, global warming, persistent plutonium, reparations for slavery, economic development, and population policy). Let us turn our attention to concepts and definitions, and attempt to devise tools that will enable us to put the various dimensions of the problem in some kind of order.

*169 B. Concepts and Definitions

We shall begin with the notion of a generation and the meaning of intergenerational. We shall then proceed to a sketch of the conceptual landscape of the ethical dimension of intergenerational ethics. After noting a distinction between political and personal morality, we will focus on the concept of justice, and the various ways that concept can be specified.

1. The meaning of intergenerational

a. three meanings of generation

Discussions of intergenerational justice might be founded on the notion of a generation. Popular ideas about generations are somewhat muddled. There are several distinct senses of the term "generation," three of which are explored here.

i. demographic cohort generations

We sometimes talk about the duties owed by the Baby Boomer generation to their parents or of the difficulties that Generation X'ers (or Y'ers) will face in paying the Social Security. Of course, the notion of a generational cohort is mostly cultural, although some great event (such as World War II) may create a fuzzy-edged demographic unit (the Baby Boomers) that may be a useful shortcut for the discussion of public policy questions (e.g., Case Seven: social security) that involve issues of intergenerational justice. For the sake of precision, let us call this notion of a generation, a "demographic cohort generation" (or DCG, for ease of reference). Note that membership in a DCG is based on fuzzy criteria. Consider the DCGs involved in social security. Persons born in 1954 are almost certainly considered Baby Boomers; persons born in 1970 are very likely Generation X'ers, but absent a stipulated definition, there can be no sharp line between the two generations. [FN14] The underlying demographic phenomenon, the so-called Baby Boom that resulted from World War II, *170 has no sharp trailing edge and hence there is no bright line demarcating the generations. [FN15]

ii. lineal descent generations

The notion of a generation may be somewhat sharper edged in the context of a family where grandparents, parents, and children form distinctive cohorts that form well-defined familial generations. Of course, as the definition of a family grows more inclusive, the line between generations will grow fuzzier.

Thus, imagine a family defined by an initial pair of parents (generation 1 = 2 parents), with many children (generation 2 = 10), and more grandchildren (generation 3 = 28) and great-grandchildren (generation 4 = 49). Now add spouses, whose ages vary from the lineal descendents of the initial pair in a roughly normal distribution. At a family reunion, there will be a precisely defined answer to the question as to what generation a given lineal descendent of the initial pair belongs. On the other hand, some great-grandchildren will be older than some grandchildren, and some spouses will be older than their partners' aunts or uncles, or younger than their partners' nephews and nieces. Once the notion of a generation is considered in an extended family with more than one line of descent, with the parents or siblings of spouses added, it becomes ambiguous or fuzzy; when only one line of descent is involved, then generations can be defined with precision, although age cohorts and generations need not coincide. Let us refer to the precise conception of a generation within a single line of lineal decent as a "lineal descent generation" (LDG, for short).

iii. unborn future generations

There is yet another use of the term generation that figures into discussions of intergenerational justice. We use the phrase "future generations" to refer to the persons who will exist in the future but who are not yet born. Sometimes by this phrase we mean persons who will not be born during the lifetime of the speaker and her audience, or even during the lifetime of any person now alive. This last *171 meaning is particularly important for some problems of intergenerational justice, because our duties towards persons who will not be born until after every person now alive is dead may be especially problematic. Let us stipulate that when we use the phrase "unborn future generations" (UFGs, for short), we shall refer to all future persons who will not be born until the last person now alive has died. [FN16] Of course, some members of a UFG will belong to the same LDG as a person now alive; these are two quite different senses of the term generation. Less frequently discussed are "deceased former generations" (DFGs), e.g., persons who lived at a former time but who are now all deceased.

b. the meaning of intergenerational

The phrase "intergenerational" obviously means "between generations," but because the notion of a generation is ambiguous, the phrase is ambiguous as well. We might refer to relationships between DCGs, or between LDGs, or between the current generation and UFGs. Each of these meanings of intergenerational is distinct, and we should attempt to avoid any confusion that might result from ambiguity.

One final point about the meaning of generations can be explored in the context of a thought experiment. Imagine a planet inhabited by an intelligent species (call them the "fenix") that is somewhat similar to humans with the following dramatic exceptions. This species reproduces through eggs. All of the females of species lay their eggs at more or less the same time, and all of the eggs hatch at more or less the same time following the deaths of all of the parents. Young fenix emerge from the eggs able to feed and care for themselves, with food, shelter, and clothing that have been prepared by their now deceased parents. For the fenix, the idea of a generation is precise. Everyone knows exactly the generation to which they belong. Demographic cohorts correspond exactly with lineal descent generations, and from the point of view of the fenix parents, every *172 fenix child is a member of an unborn future generation. The fenix thought experiment demonstrates that the ambiguity in the term "generation" is a function of the form of life that is characteristic of humans and a product of human biology.

c. the structure of intergenerational duties

Some issues of intergenerational justice may involve intergenerational rights or duties. A first distinction concerns the direction of the duty in time. A current generation may owe a duty to past generations. Intergenerational ethics may involve backward-looking duties (younger to older generations) or forward-looking duties (older to younger generations), and such duties may be contemporaneous (owed while the older and younger generations coexist) or non- contemporaneous (owed to persons yet unborn or deceased). The following table illustrates the possibilities:

Table 1: Examples of Intergenerational Duties

Backward Looking Forward Looking

Contemporaneous Social Security (The duty of Care and Feeding (The

the younger working duty of parents to care

generation to finance social for their children)

security benefits for the

elderly)

Non-contemporaneous Reparations (The duty of a Persistent Plutonium (The

current generation to obligation of the

compensate a deceased former current generation not

generation for an injury to cause pollution that

done to them) [FN17] will injure unborn

future generations)

*173 2. The dimensions of intergenerational ethics

Frequently, the topic of morality between and among generations is characterized as a problem of "intergenerational justice" [FN18] or sometimes "intergenerational equity." [FN19] This may well be the case, but before we focus on justice, we need to consider the alternatives. Let us consider initially, the distinction between personal and political morality.

a. personal and political morality

Justice is not the only moral or ethical concept. Some of our moral obligations are obligations of justice, but there are other moral concepts such as beneficence, temperance, caring, and charity. Moreover, we should consider the possibility that there is a distinction between the ethical considerations that bear on decision making by individuals and the considerations of political morality that govern decisions made by public institutions. For example, the case of legacies and bequests deals with the morality of intergenerational wealth transfers. It would not be implausible to believe that justice has little role to play in this case. Perhaps ethics does come into play when I decide whether to leave an estate for my children or spend the money on travel, but it does not seem quite natural to say that either decision could be characterized as unjust. Spending the money now might be unloving, uncaring, or uncharitable, but it would hardly be unjust. The decision to make a bequest is a personal one, although it *174 is tied to social decisions (such as whether to impose an estate and gift tax). The case of legacies and bequests strongly suggests that at least some questions of intergenerational ethics are not questions of intergenerational justice.

Provisionally, let us set aside the questions of personal morality, and focus on those of political morality. Once we are in the realm of the public, questions of justice come to fore. Even if justice is not the only ethical concept we need to investigate, it seems reasonable to begin there.

b. justice

With the notion of a generation clarified, the next step is to turn to the concept of justice. The concept of justice is an elusive one, and even a sketchy treatment could not be accomplished in this article. Nonetheless, we need some idea of what we are talking about. One place to begin would be with Aristotle's distinction between corrective (or rectificatory) justice and distributive justice. We can then turn to the distinction between the concept of justice and the various conceptions (sets of principles or theories) that specify that concept.

i. corrective and distributive justice

In his Nicomachean Ethics, Aristotle distinguished between corrective (or rectificatory) justice and distributive justice. [FN20] By stipulation, let us use these terms in the following senses. Corrective justice is concerned with justice in transactions in general and the righting of wrongs in particular. [FN21] Thus, criminal punishments or damage awards in tort actions can be viewed as attempts at corrective justice. We punish the criminal or award damages from the tortfeasor to the tort victim in order to correct an injustice. [FN22] Distributive justice is concerned with sharing the benefits and burdens of social cooperation. [FN23] For example, distributive justice is implicated by the question *175 whether there should be a so-called poll tax (the same amount to be paid by every citizen) or a flat tax (the same percentage of income paid by every citizen) or a progressive tax (those with higher incomes or consumption levels pay a higher percentage of income or consumption).

Intergenerational justice might involve either corrective or distributive justice. Consider corrective justice. For example, take the case of persistent plutonium. Suppose that one generation constructs and operates the plutonium power plants and then realizes the hazard. The question as to whether the polluting generation owes duties to UFGs is a question of corrective justice. The polluting generation might, for example, be obligated to create a trust fund to compensate UFGs for the injuries they will suffer or to invest in cancer research to attempt to mitigate the future harms. The case of reparations for slavery is also an example of corrective justice: Wrongs done by past generations may give rise to duties of corrective justice held by current generations. Finally, when limited to parents and their children, the case of nursing the elderly may involve corrective justice: Children may owe their parents compensation for the care and feeding that their parents provided them when the children were young.

Next consider distributive justice. Take the case of social security as our example. Issues about how to share the benefits and burdens of the Social Security system between DCGs are classic examples of distributive justice. Similarly, the case of entailed estates involves questions about the distribution of wealth between LDGs. Notice that some of our cases may involve both corrective and distributive justice. Take nursing the elderly: Corrective justice may be involved when we consider parents and their children, but distributive justice may be the primary focus when we consider health policy, e.g., the level of public funding for social health insurance for the elderly (Medicare).

Even though intergenerational justice can involve issues of corrective justice, I shall put such questions aside for the remainder of this article. In part, this decision is simply one of convenience; distributive justice is a large enough topic. In part, this decision is based on the premise that the issues of distributive justice are more fundamental. The question whether we have a duty to refrain from introducing persistent plutonium into the environment is a question *176 about the distribution of rights and obligations across generations. Before we can address questions of corrective justice, we need to know what constitutes an injustice, i.e., a violation of rights or failure to meet obligations. If the generation that introduces persistent plutonium does no wrong, then corrective justice never arrives on stage.

ii. concepts and conceptions of justice

When we talk about distributive justice, what we mean will depend on our theory of distributive justice. Following John Rawls, let us make a distinction between the concept of distributive justice and particular conceptions (theories or sets of principles) of distributive justice. [FN24] Egalitarians, libertarians, and utilitarians might all agree that rights, resources, and burdens should be justly distributed across generations, but they would likely disagree about what that means. Libertarians might emphasize the idea that one generation may not constrict the basic rights and liberties of future generations, while egalitarians might conceivably hold that each generation has an equal claim on natural resources. They all have views about the concept of distributive justice, but they disagree about what is the best, correct, or true conception. When we turn to the subject of intergenerational justice, the distinction between concept and conceptions can be used to raise two helpful questions. First, we may ask whether the concept of justice is the right one to handle the concrete problems that we need to address. Perhaps it is the concept of beneficence or that of temperance that comes into play, and not that of justice at all. Second, we ask how different conceptions of justice handle the problem of intergenerational justice.

III. Theories of Distributive Justice

Simplifying greatly, let us assume that there are three families of thought about distributive justice. Here I will provide a sketch of the ideas that unite each family and of some of the disagreements that exist within these schools of thought. After the general ideas of each *177 theory are described, I shall provide a brief outline of a particular theory that is a member of the family, and then briefly explore some of the implications of that theory for problems of intergenerational justice.

The first family, I shall call "egalitarian." The second family, I shall call "libertarian." And the third family, I shall call "utilitarian." I do not mean to imply that these theories exhaust the possibilities or classify current or historically important views. Rather, the three families classify and illustrate some of the most important thinking about distributive justice.

A. Egalitarian Theories of Distributive Justice

Consider first the family of egalitarian theories. We shall begin with the general idea of an egalitarian theory. We shall then turn to justice as fairness, the particular egalitarian theory developed by John Rawls. [FN25] Finally, we shall consider the implications of Rawls's theory for the question of intergenerational justice.

1. The general idea of an egalitarian theory

As I shall use the term, the core idea of an egalitarian theory of distributive justice is that the relevant outcomes or institutions should provide each and every relevant individual or group an equal (or equality- based) share of the relevant goods, resources, capacities, opportunities, entitlements, or states. This formulation is so abstract that it does not tell us much. Four elements of the core idea require further specification. First, what are the relevant goods? Second, what is an equal or equality-based share? Third, what are the relevant outcomes or institutions? Fourth, which individuals or groups are relevant?

To get a better sense of these four questions, let us take one simplified example of an egalitarian theory. Let us suppose that the relevant good is pleasure and an absence of pain. Let us further suppose that by an equal share, we mean that each person should receive roughly the same balance of pleasures and pains. [FN26] Next, let us *178 suppose that the equal share of pleasure and pain is to be measured in terms of an outcome, i.e., the accrued balance of pleasures and pains over the whole life of each individual. Finally, let us suppose that each and every human being currently alive is the relevant group. The resulting theory of distributive justice is that each person ought to achieve roughly the same amount of pain and pleasure over the course of her lifetime. Call this view "hedonistic egalitarianism." This may not be a theory anyone is likely to advocate, but it illustrates the kinds of answers that can be given to the various questions facing an egalitarian theory.

One final comment on the general idea of an egalitarian theory of distributive justice: The first question, "What is the relevant good?" has been the subject of a substantial debate between and among egalitarians and their critics. The question, "Equality of what?" has produced a remarkable variety of answers, including "equality of welfare," "equality of opportunity for welfare," "equality of resources," and so forth. [FN27]

2. Justice as fairness

Perhaps the most prominent egalitarian theory of distributive justice is "justice as fairness," [FN28] the theory advanced by John Rawls in A Theory of Justice [FN29], Political Liberalism, [FN30] and Justice as Fairness: A Restatement. [FN31] As Rawls explains, "[t]he aim of justice as *179 fairness . . . is practical: it presents itself as a conception of justice that may be shared by citizens as a basis of a reasoned, informed, and willing political agreement." [FN32] An adequate summary of Rawls's rich and complex theory is outside the scope of this article, but the portion of his theory that is most relevant to our current enterprise is his presentation of the argument for two principles of justice. [FN33] The full statement of the principles and the accompanying priority rules and general conception is as follows, with changes made in Political Liberalism and Justice as Fairness: A Restatement set in brackets in the text and noted in appropriate footnotes:

First Principle [FN34]

Each person has the same indefeasible claim [FN35] to a fully *180 adequate scheme of equal [FN36] basic liberties, which scheme is compatible with the same scheme of liberties [FN37] for all. . . . [FN38]

Second Principle

Social and economic inequalities are to be arranged so that they are both:

(a) to the greatest benefit of the least advantaged, consistent with the just savings principle, and

(b) attached to offices and positions open to all under conditions of fair equality of opportunity.

First Priority Rule (The Priority of Liberty) [FN39]

The principles of justice are to be ranked in lexical order, and therefore, liberty can be restricted only for the sake of liberty. There are two cases:

(a) a less extensive liberty must strengthen the total system of *181 liberties shared by all;

(b) a less than equal liberty must be acceptable to those with the lesser liberty.

Second Priority Rule (The Priority of Justice over Efficiency and Welfare)

The second principle of justice is lexically prior to the principle of efficiency and to that of maximizing the sum of advantages; and fair opportunity is prior to the difference principle. There are two cases:

(a) an inequality of opportunity must enhance the opportunities of those with the lesser opportunity.

(b) an excessive rate of saving must on balance mitigate the burden of those bearing this hardship.

General Conception

All social primary goods--liberty and opportunity, income and wealth, and the bases of self-respect--are to be distributed equally unless an unequal distribution of any or all of these goods is to the advantage of the least favored. [FN40]

The argument for the two principles is rich and complex and cannot be summarized here. Two important ideas deployed in that argument, the "original position" and "reflective equilibrium," are discussed in the sections that follow. [FN41] Very broadly, we might say that Rawls argues that the two principles are those "that free and rational persons . . . would accept in an initial position of equality as defining the fundamental terms of their association." [FN42] The "initial position of equality" is specified by laying out a hypothetical choice situation, "the original position," where representative parties select from a list of alternative principles of justice from behind a "veil of ignorance" which excludes from the parties knowledge of "how the various alternatives will affect their own particular cases." [FN43] We aim for a theory that is in reflective equilibrium in the sense that our considered judgments, about specific cases and general principles, are as consistent with one another as is possible.

*182 It is illuminating to contrast Rawls's theory with our simplified theory of hedonistic egalitarianism. Hedonistic egalitarianism answers the "equality of what" question with pleasure and pain. Rawls answers that question with the primary goods, [FN44] which include rights (such as freedom of speech) as well as wealth and income. Hedonistic egalitarianism takes individual lives as its subject. Justice as fairness, by way of contrast, takes the basic structure of society as the subject of justice. [FN45] Hedonistic egalitarianism applies directly to individuals, whereas justice as fairness applies to the basic institutions (the structure of government and the economic system). If the basic structure is just, then justice as fairness does not condemn inequalities at the individual level, but hedonistic egalitarianism would condemn such inequalities. [FN46]

Hedonistic egalitarianism requires "rough equality," acknowledging that strict equality of pleasures and pains is both impossible to measure and futile as a goal. Rawls's theory does not require even rough equality with respect to all relevant goods. Instead, the first principle requires strict equality with respect to the basic liberties (such as freedom of speech), while the second principle permits differences in wealth and income so long as such differences work to the advantage of those who are least well off. Moreover, Rawls's theory does not apply directly to the share of the basic goods held by particular individuals; rather, it applies to the basic structure of society. Even if the basic structure is just, the two principles may not be achieved with respect to each and every individual. [FN47]

*183 3. Justice as fairness between generations

How then does justice as fairness handle the problem of intergenerational justice? Section 44 of A Theory of Justice [FN48] is the classic [FN49] modern treatment of the issue. [FN50] Recall that the difference principle requires that social and economic inequalities are to be arranged so that they are to the greatest benefit of the least advantaged, consistent with the just savings principle. Why does the difference principle need to be supplemented by a just savings principle? To begin, the difference principle alone does not address the problem of intergenerational justice. Although actions by the current generation affect future generations (UFGs), no generation can aid its predecessors. As Rawls puts it, "It is a natural fact that generations are spread out in time and actual economic benefits flow only in one direction. This situation is unalterable, and so the question of justice does not arise." [FN51] Moreover, without a just savings principle, the current generation might make the least advantaged better off by consuming all capital resources, leaving nothing for future generations.

Recall that the two principles of justice were adopted by the parties to an original position behind a veil of ignorance. One way to derive a just savings principle might be to exclude from the parties knowledge of the generation to which they belong, but this is not the route Rawls chooses. Instead, the parties know that they are contemporaries [FN52] but they do not know the place of their generation in time. [FN53] They adopt the savings principle that "they would want *184 preceding generations to have followed, no matter how far back in time." [FN54]

Rawls did not believe that it was possible to specify a just savings rate with particularity. [FN55] However, some limits on such rates can be articulated:

[A] savings principle is a rule that assigns an appropriate rate (or range of rates) to each level of advance. . . . Presumably different rates are assigned to different stages [of economic development]. When people are poor and saving is difficult, a lower rate of saving should be required; whereas in a wealthier society greater savings may reasonably be expected since the real burden of saving is less. Eventually, once just institutions are firmly established and all the basic liberties effectively realized, the net accumulation asked for falls to zero. At this point, a society meets its duty of justice by maintaining just institutions and preserving their material base. [FN56] The just savings principle addresses only some of the issues of intergenerational ethics. It is most obviously relevant to economic development, but it may have implications for other cases as well. For example, the state of the environment can be viewed as a capital resource, and hence intergenerational pollution might be constrained by the just savings principle. Thus, policy choices about persistent plutonium and global warming might be constrained by the just savings principle, although the constraint might be fairly loose. Degrading the environments of future generations would be consistent with the just savings principle so long as the total bundle of primary goods passed to future generations was adequate.

Some of the other cases are addressed or influenced by the two principles of justice as well. For example, the case of legacies and bequests is not directly addressed; assuming a just basic structure, each individual is free to make such gifts or bequests as she pleases. Rawls does believe, however, that the difference principle may require some form of taxation to be levied on the recipient of *185 bequests. [FN57] Similarly nursing the elderly involves issues that are not directly constrained by the just savings principle if we focus on the duties of parents to their children, although a social guarantee of adequate medical care may be required by the difference principle. [FN58] Social security is directly addressed by the difference principle, and it may well be that a generous system of social security payments is required in order to insure that those who are least advantaged benefit from inequalities of wealth. [FN59]

B. Libertarian Theories of Distributive Justice

Again, I will begin with the general idea of libertarianism, and then proceed to discuss a particular theory, Randy Barnett's liberal conception of justice, and its implications for intergenerational ethics.

1. The general idea of libertarianism

Libertarianism represents another approach to the question of distributive justice. Characteristically, libertarian theories do not impose direct constraints on the distribution of goods (wealth, income, happiness, and so forth). Rather, libertarian approaches to justice emphasize certain basic liberties, especially rights to own property and to make contracts free of interference. Locke's theory, as developed in the Second Treatise of Government, [FN60] is sometimes thought *186 to be a libertarian theory, [FN61] with parties in the state of nature agreeing to a "night-watchman" state. [FN62] Seen from a different angle, however, libertarianism can be viewed as an egalitarian theory of distributive justice. Libertarians may believe that the relevant good to be distributed is liberty, and that each and every person ought to have the maximum possible equal share of liberty. Giving the maximum share of equal liberty implies that other goods, e.g., wealth and income, will not be distributed equally.

2. The structure of liberty

Let us consider a specific libertarian theory, the one advanced by Randy Barnett in The Structure of Liberty. [FN63] Barnett calls this set of ideas "the liberal conception of justice." [FN64] The argument for the liberal conception focuses on three central problems of human interaction: the problem of knowledge, the problem of interest, and the problem of power. [FN65] Barnett argues that, given "the goal of enabling persons to survive and pursue happiness, peace, and prosperity while living in society with others," [FN66] these fundamental problems of human interaction create constraints on the possible forms of social organization. Unless society is organized to respect rights of several property, freedom of contract, restitution, and self-defense, the problems of knowledge, interest, and power will make it impossible for all persons (or each and every person) to survive and pursue happiness, peace, and prosperity. Barnett's liberal conception of justice is simply a detailed formulation of the content of the rights that must be respected. The full statement of the liberal conception is quoted in *187 full in an accompanying footnote, [FN67] but for our purposes three of these rights are most important:

(1) The right of several property specifies a right to acquire, possess, use, and dispose of scarce physical resources--including their own bodies. Resources may be used in any way that does not physically interfere with other persons' use and enjoyment of their resources. While *188 most property rights are freely alienable, the right to one's person is inalienable.

(2) The right of first possession specifies that property rights to unowned resources are acquired by being the first to establish control over them and to stake their claim[.]

(3) The right of freedom of contract specifies that a rightholder's consent is both necessary (freedom from contract) and sufficient (freedom to contract) to transfer alienable property rights--both during one's life and, by using a "will," upon one's death. A manifestation of assent is ordinarily necessary unless one party somehow has access to the other's subjective intent. [FN68]

Barnett's libertarianism implies a very limited role for government. At the most, government should protect private property and enforce contracts. Even that role may not be justified if private courts and law enforcement agencies can be created by voluntary agreements.

3. The structure of intergenerational justice

Barnett's theory does not directly address questions of intergenerational ethics, but his principles bear on several of the cases. [FN69] The right of first possession implies that resources may be appropriated by the first generation to which they become available. The right of several property implies that the owner may consume the resource without re