This article aims to establish a framework for discussions of law and public policy. To do that it is necessary to understand their purpose, for it is against that purpose that the debate over good and bad law, good and bad policy will range. The current debate is based upon “interests” and “ rights.” It treats interests as the purpose of public policy, so that good policy is policy that responds to and delivers on the interests of groups and organizations. A policy that does that is said to be “responsive.”

The trouble is that it isn’t clear why public power should respond to private interests. Is the choice between interests simply a matter of economic and electoral power? Is the “public interest” simply some accumulation of private interests? If so, which ones? Some interests must be preferred over others but without a sense of purpose there is no framework for preferring one set of interests over another. We might assume, for example, that if one group had an interest in destroying the interests of another group, the first group’s interest would not become public policy. But often it does. Why is that?

Interests are bounded by rights. So those who would build a highway must compensate the people whose land is taken for the project—the owners have a “right” in their land. But how about the neighboring residents, whose lives will be disrupted by the construction? Don’t the neighborshave a right to the quiet enjoyment of their land? If they do, it is only a sentimental right, for they will not be compensated for the disturbance. Why should that be so? How do we know what rights to recognize? Where do rights begin and end? Are rights simply interests that are more widely accepted by the public?

On its face, freedom does not offer much promise for grounding law and policy. Variously defined as “the condition of being free of restraints” or “the capacity to exercise choice,” the concept seems hopelessly vague and circular. To act as a framework for the public discussion of law and policy, freedom must have a concrete meaning that allows us to identify it with specificity and to determine the conditions that expand and contract it.

The purpose of this article is to supply that concrete meaning and to see how it could provide the fulcrum for defining interests and rights. On a strictly sentimental level, freedom is clearly a central part of the rights and interests that animate political debate—rights and interests are important parts of a free society. But that sentimental notion has not generated a framework that makes it possible to distinguish interests that should be implemented from those that should not or to distinguish rights that exist from those that are dreams.

Freedom is a universal experience, the experience that each one of us has as we consider the alternative actions that we may take. Its magnitude depends upon the number, range and value of those actions. A person whose choices amount to seven different ways to carry a pile of rocks from here to there does not experience freedom. That person’s freedom will likely be improved by the addition of a few other alternatives, such as the opportunity to confront the person who assigned him the duty to move the rocks.

It follows from this that good law expands the number, range and value of alternatives facing the people covered by the law, as those people perceive the alternatives. A political process designed to respond to interests can approximate good law, but only if the public debate over interests recognizes that freedom is the point. Interests unbounded will otherwise institutionalize differences in power rather than the common interest in freedom.

The first step in the explication of freedom is to discern what it means to the individual. Then we will move to its meaning in public decisions.

The experience of freedom can be thought of as a collection of alternatives that a person perceives at any given time—the . freedom set

Consider Ted, who has finished the Sunday paper and is thinking over his alternatives for the afternoon.

. Three alternatives present themselves. Each one is attractive. He can set up a game of tennis with a friend, get into his car and visit his daughter and her children, or watch an NFL game. There are probably thousands of other things that Ted could do with his afternoon—a trip to the local art museum is a likely possibility. But they are either things that he has no interest in doing or things that he doesn’t realize are a possibility.

Ted can only do one of these three things. When he chooses one, he must give up all of the others. The “ cost” of his choice is measured by what he had to give up--the value of the alternative he had to forego. If he chooses wisely, he will perceive that the value of the choice he made exceeds the value of any of the other things that he could have done. His afternoon will not have been wasted.

The union of subjective and objective, of the freedom set and the real set, is the person’s prospects—the list of alternative actions that the person can actually produce. That part of the real set that lies outside the freedom set consists of alternatives the person is unaware of or is not interested in.

As he sits at his kitchen table considering his alternatives, for example, Ted may not know there is a pickup touch football game forming in the park two blocks away. If he knew, he might well choose to join it. Until he finds out about it, it is not one of his prospects. Or he may know of it, but have no interest in playing football—not at his age. It is not, for him, one of his prospects.

Prospects are particularly important in law, for they provide a coherent basis for compensation. Were Ted to suffer a serious personal injury, for example, he would experiences a drastic reduction in his prospects, in the real portion of his freedom set. He might be able to watch the football game on Sunday afternoon, but the tennis game and the visit to his grandchildren would have been removed from his list of alternatives. And the income he lost while recovering would reduce his resources, erasing any alternatives that required those resources and adding a series of actions necessary to recover from the injury.

The concept of prospects provides an objective framework for compensating for the non-monetary losses to the victim’s freedom. Rather than basing compensation on the inherently unknowable value of the pain that he had suffered, a jury could objectively assess the impact of the injury on Ted’s causal capacity. If the injury prevented him from playing tennis, that would be counted as part of his losses. Where pain and suffering is irreducibly subjective, making it a deeply problematic basis for compensation, prospects have an objective dimension that makes assessing and valuing them a meaningful activity.

Life may collapse the person’s freedom set, harming his perception of himself as an effective actor or diminishing his causal capacity, perhaps through injury or disease. Constraint is the general term for reductions in freedom, whether real (e.g., loss of a limb) or imagined (e.g., paranoia). Constraints come in two flavors that have vastly different implications in the law. “Willed” constraints are the result of the actions of other people. They are produced by intelligence, and they can be reduced or eliminated by responsible behavior. Willed constraints, in the form of injuries, lies, breaches of promise, monopolizing, abuse of office, and so on, are the primary subject matter of law.

“Natural” constraints are the constraints that are not driven by will—gravity, disease, ignorance, decay, and so on. Natural constraints are not legally significant. Viruses, droughts, and gravity are not moral actors; no legal action can be brought against them. But natural constraints that are under the control of a willed actor do support a cause of action, say, against the logger who carelessly felled the tree onto your car.

To say that freedom is caused is simply to say that changes in the world are causally related to the person’s subjective experience of alternatives. It is enhanced by the invention of activities once unimagined, by new medical procedures that preserve capabilities once lost, by education that expands the person’s range of effective action. The person learns to enjoy through exposure to the enjoyment of others, learns to have confidence in her own causal capacity by the guidance of others, learns to seek new ideas and skills.

A person’s causal capacity is expanded—the person is “empowered”—by changes in the world. The internet generates an explosive increase in individual prospects, making actions that were unimagined minutes before a realistic part of the person’s repertoire. Were Ted to go online on that Sunday afternoon, for example, he would discover countless activities that he might well find more interesting than the ones he was considering.

Second, law addresses natural constraints by creating entitlement systems. Creating a property law system, for example, lets people establish an authoritative relationship with the resources that constitute an essential part of their causal capacity. The person who is protected by copyright law has a way of turning the tunes in his head or sketches on a pad of paper into an economic resource.

The binary nature of law—the fact that it operates in two quite different ways to enhance freedom—increases the complexity of the story. In what follows I will take up each one and then address the confusion that arises when they are confused with each other.

The rights-enforcement role of law is entirely familiar. Rights, as has been explained elsewhere in this theory, are caused by breaches of duty that either diminish or threaten to diminish the causal capacity of another person. When it enforces rights, the court uses coercion against the wrongdoer on behalf of the victim. The obvious question is, how much coercion is the court justified in using? The wrongdoer has diminished the prospects of the victim. In return, the court will diminish the propects of the wrongdoer.

What is the court justified in doing in response to that wrong? It must exact a remedy that is proportional to the wrong that was done. In this illustration the court sets the remedy at level B, which is proportional to the severity of the wrong, at level A. 

The red line is the line of perfect proportionality at which a wrong is matched to its proportional level of coercion. To establish the correct level of remedy the court may take into account the reasons for the thief’s actions and the effect of the penalty. A rich thief, for example, will deserve a greater fine than a poor one if the severity of the penalty is to be perceived to be equivalent. And a thief who shows every sign of being willing to steal again deserves a penalty that will cause him to rethink his impulses.

But why must the court respond proportionally to the wrong? The answer to that question is buried deep within human biology, but its basis can be sensed in the fact that the experience of freedom is the same for all. Whether the constraints are caused by a wrongdoer or a judge, they diminish the experience of freedom. We can think of the requirement of proportionality as the law of conservation of human freedom, where the freedom of the wrongdoer stands on the same level of respect with the freedom of the victim. Because of his action, the wrongdoer subject to an appropriate reduction in his freedom, but his capacity for freedom itself is entitled to respect, so only what he yields by his actions should be taken from him.

In the Biological Basis of Law the imperative of proportionality is set out as a principle, the principle of greatest liberty: Each person is entitled to the greatest liberty consistent with the same entitlement in all people. The wrongdoer breaches that principle, reducing the liberty by diminishing the prospects of another. That justifies the proportional reduction in the wrongdoers prospects. But that action by law itself creates a risk that the law will breach the principle. Its actions reduce liberty as surely as the wrongdoer’s.

Liberty is a subset of the larger concept of freedom. The experience of freedom is the experience of being without constraints, either willed constraints and unwilled, or natural, constraints. Liberty is freedom from willed constraints. One is “at liberty” to the extent that one’s freedom set is not constrained by the will actions or threatened actions of others.

The principle of greatest liberty applies to everyone, most definitely to those who use the law to intentionally dim the prospects of wrongdoers. If it is fundamental that no person may diminish the liberty of another, it is doubly fundamental that those whose business it is to diminish the liberty of others are deeply contstrained as they do it. To act within the principle, law must render to the wrongdoer what is due him, and what is due him is a diminution in prospects proportional to the diminution he caused.