In the previous chapter I argued that simple statements of libertarian principle lead to unacceptable conclusions and must therefore be rejected. There is no obvious logical inconsistency in a moral principle that implies that nobody should be permitted to breathe, but it is not a principle that many people are likely to accept.

One possible response is that libertarianism is an absolute principle, an ultimate value which cannot be overridden, but that it is not adequately expressed by the simple statements I have been attacking. If those statements are only approximations to a much more complicated and subtle description of libertarian principle it is hardly surprising that the approximation sometimes breaks down in difficult situations.

This is a view with which I have a good deal of sympathy but it is not very useful for answering real-world questions, at least until someone manages to produce an adequate statement of what libertarian principles really are. Moral philosophy is a very old enterprise and its rate of progress has not been rapid in recent centuries, so I do not plan to hold my breath while I wait.

A second response, and one with which I also have a good deal of sympathy, is that there are a number of important values in the world. They cannot be arranged in any simple hierarchy or at least are not going to be any time soon. Individual liberty is an important value in and of itself, not merely as a means to happiness, so we should not be willing to sacrifice large amounts of it in exchange for small amounts of happiness. But liberty is not the only value, nor is it infinitely important compared to other values, so we should not be willing to sacrifice unlimited amounts of happiness for small gains in liberty.

A third possibility is that the conflict between libertarian and consequentialist values is only apparent. Perhaps there is some deep connection between the two so that libertarian ethics, properly understood, is the set of rules that leads to the maximum of human happiness. The counterexamples given in the previous chapter must then be interpreted as some combination of mistakes about what is possible—for some reason those situations could not arise in the real world—and mistakes about what is implied by a correct statement of libertarian principle. Something along these lines seems to be suggested by the arguments of those libertarian philosophers who claim to get their principles not by generalizing from what seems right or wrong to them but by deducing what set of rules is appropriate to the nature of man.

One argument in favor of this approach is that it fits the observation that libertarianism and utilitarianism, while quite different in principle, frequently lead to the same conclusion. Through most of this book I have used consequentialist arguments to justify libertarian conclusions. By doing so I provided evidence that the potential conflicts between the two approaches which I discussed in the previous chapter are the exception rather than the rule. In Chapter 31 I tried to show that the institutions of anarcho-capitalism would tend to generate libertarian laws. A key step in that argument was my claim that the value to individuals of being able to run their own lives is typically greater than the value to anyone else of being able to control them—or in other words, that increases in liberty tend to increase total utility.

A fourth possibility, the last which I will consider, is that libertarianism is wrong and we should accept utilitarianism instead. According to the strict utilitarian position, rules, actions, ethics, must be judged solely by their effect on the sum (some utilitarians would say the average) of human happiness. Whatever increases happiness is good, whatever decreases it bad. Libertarian principles are then valued only as a means, a set of rules that frequently lead to increases in total utility and should be rejected when they do not. This again is a possible interpretation of arguments that claim to derive libertarian principles from the nature of man although not, in my experience, an interpretation that those who make such arguments are willing to accept.

One argument against utilitarianism is that it cannot be a correct moral rule because there is no way we can tell whether we are following it. We cannot observe other people’s utility and are therefore unable to judge what will increase it. Even if we could observe individual utilities, we do not know how to compare the utility of different people and so have no way of judging whether a gain in happiness to one person does or does not balance a loss to another.

I find this argument unconvincing because the claim it is based on is too strong. Consider the act of buying a present. If you really have no knowledge at all about what makes other people happy then buying a present is pure guesswork; you might just as well open a page of the Sears catalog at random, throw a dart at it, and buy whatever you hit. Nobody believes that; if we did, we would not buy presents.

Consider a court awarding damages. If we really know nothing at all about other people’s utility, how can a court decide how much someone owes me for breaking my arm? For all the judge knows, I enjoyed having my arm broken. Assuming that I disliked it, he has no way of knowing whether my disutility for a broken arm is measured by a penny or a billion dollars.

We give presents, we award damages, and we do not believe that other people’s utility is entirely unobservable. What we do believe, or at least what many of us believe, is that each of us knows more about his own values than most other people do and that people are therefore usually better off deciding what they want for themselves. That is one of the main arguments in favor of a free society. It is a long step from that to the claim that we know nothing at all about other people’s values.

Even if we were entirely unable to observe other people’s values, that would not necessarily prevent us from constructing a society designed to maximize total utility. Each person knows his own values, so all of us put together know everybody’s values. In order to maximize the total utility of the society we would construct rules and institutions that utilized all of that information via some sort of decentralized decision making system, with each person making the decisions that require the particular knowledge he has.

This is not, of course, merely an abstract possibility. One of the strongest arguments in favor of letting people interact freely in a market under property rights institutions is that it is the best known way to utilize the decentralized knowledge of the society, including the knowledge that each individual has about his own values. The field of welfare economics largely consists of the analysis of the rules that lead to optimal outcomes under specified circumstances, where the outcomes are evaluated in terms of the preferences of the individuals concerned. One originator of modern economics, including much of welfare economics, was Alfred Marshall, an economist and utilitarian who viewed economic theory in part as a way of figuring out how to maximize total utility.

Even if individual preferences can be observed, either directly or as reflected in actions, we are still left with the problem of comparing them. How can we say whether something which makes one person worse off and another better off produces a net increase in human happiness?

The answer, I believe, is that we may not be able to make such comparisons very well or describe clearly how we make them, but we still do it. When you decide to give ten dollars’ worth of food and clothing to someone whose house has just burned down instead of sending a ten-dollar check as an unsolicited gift to a random millionaire, you are expressing an opinion about which of them values the money more. When you decide where to take your children for vacation, you are making a complicated judgment about whether their total happiness will be greater camping in a forest or wading on the seashore. We cannot reduce the decision to a matter of precise calculation, but few of us doubt that the unhappiness A gets from the prick of a pin is less than the unhappiness B gets from being tortured to death.

Utilitarianism is a possible moral rule. The difficulties of applying it to real world problems are substantial, but so are the difficulties of applying an alternative rule such as minimizing coercion. One would face very similar problems in defining and measuring the amount of coercion and in judging the tradeoff between increased coercion for one person and decreased coercion for another.

Utilitarianism is a possible moral rule, but it is not one that I am willing to accept. Why? For the same reason that I reject all simple statements of libertarianism: because I can construct hypothetical situations in which it seems clear to me that the rule gives the wrong answer.

You are the sheriff of a small town plagued by a series of particularly brutal murders. Fortunately, the murderer has left town. Unfortunately, the townspeople do not believe that the murderer has left and will regard your assertion that he has as an attempt to justify your own incompetence in failing to catch him.

Feeling is running high. If no murderer is produced, three or four innocent suspects will get lynched. There is an alternative. You can manufacture evidence to frame someone. Once he has been convicted and hung, the problem will be gone. Should you do it?

On utilitarian grounds, it seems clear that the answer is yes. You are killing one innocent person but saving several, and you have no reason to believe that the one you kill values life any more than the ones you save. You yourself may receive disutility from knowing that you have framed an innocent man, but if it gets bad enough you can always kill yourself, leaving a profit of at least one life’s worth of utility.

I am not willing to accept the conclusion. In an earlier hypothetical I said that I would steal. In this one, I would not frame. To save a million lives, perhaps, but for a net profit of one or two, no. It follows that I am not a utilitarian.

Although I reject utilitarianism as the ultimate standard for what should or should not happen, I believe that utilitarian arguments, or consequentialist arguments more generally, are usually the best way to defend libertarian views. While most people do not believe that maximizing human happiness is the only thing that matters, most do believe that human happiness is important. Libertarians are not the only ones who avoid conflicts by believing that the system they favor works both morally and practically. To the extent that I can show that a particular libertarian proposal—abolition of heroin laws, or minimum wage laws, or all government—produces attractive results, I have an argument which will have some weight in convincing almost anyone to support it.

So one reason to base my arguments on consequences rather than justice is that people have widely varying ideas about what is just but generally agree that making people happy and prosperous is a good thing. If I argue against heroin laws on the grounds that they violate the addicts’ rights, I will convince only other libertarians. If I argue that drug laws, by making drugs enormously more expensive, are the chief cause of drug-related crime, and that the poor quality control typical of an illegal market is the main source of drug-related deaths, I may convince even people who do not believe that drug addicts have rights.

A second reason to use practical rather than ethical arguments is that I know a great deal more about what works than about what is just. This is in part a matter of specialization; I have spent more time studying economics than moral philosophy. But I do not think that is all it is. One reason I have spent more time studying economics is that I think more is known about the consequences of institutions than about what is or is not just, that economics is a much better developed science than moral philosophy.

If so, the implications are not limited to the best choice of arguments with which to convince others. In the previous chapter I gave a long list of questions which I saw no way of using libertarian principles to answer. In the next chapter I will argue that they are all questions that can, at least in principle, be answered by using economic theory to discover what rules maximize human happiness. If so, then economics is not only a better way of persuading others. It is also a better way of figuring out what I myself am in favor of.