WHEN MORAL principle is translated into practice, a critical question is whether to rely primarily on case-by-case judgments or primarily on rulebased decision making. For example, if organs for transplantation are to be allocated so that benefit to patients is maximized,' physicians could make a case-by-case judgment for each organ to decide which patient would gain the most benefit from a transplant and therefore would be the best candidate for the organ. Alternatively, physicians could rely on benefits-based rules to determine the recipient of each organ, with the idea that the rules would usually identify leading candidates for transplantation but not necessarily the best candidate each time.
I will say more about the choice between case-by-case judgments and broadly applicable rules, but an important feature of rules is their general validity. That is, rules will typically, but not always, serve their underlying principles. The general validity of a rule can be illustrated as follows. Assume that the goal in transplantation is to give organs to those patients who will live the longest with their new organs. Transplant surgeons might therefore exclude from consideration for kidney transplantation patients who are heavy drinkers of alcohol.' Such a rule would generally ensure longer survival of kidney transplant recipients, but it would also deny transplants to patients with heavy alcohol use who do unexpectedly well and ive longer than many other patients who would receive a kidney transplant.
When generally valid rules are used, they can appear to be misguided. Since they are by definition imperfect proxies for their underlying principles, they will at times yield results that seem unfair. The kidney failure patient with heavy alcohol use whose life is not shortened by the drinking will not have an opportunity for a transplant. Similarly, if state laW requires individuals to reach the age of adulthood before exercising decision making capacity, adolescents of advanced maturity may be denied decision-making authority that they deserve." Because of their imperfection, generally valid rules will often be criticized as interior to case-by-case judgments.
Such criticism, however, misses an important reason for using generally valid rules rather than individualized judgments. Often, the moral concerns that arise in the translation of principle to practice make case-by-case judgments undesirable. Thus, for example, aspects of abortion law can be misunderstood if the move from principle to practice 1s not considered. When the law permits women to have an abortion for any reason if the fetus is not viable, people frequently object to the law on the ground that it indicates that abortions are always morally permissible when the fetus is not viable. As these opponents observe, the morality of an abortion may depend not only on the fetus's viability but also on the woman's reasons for wanting an abortion. If the woman chooses an abortion to protect her health, we have a very different case than when a woman chooses an abortion because she is angry with the father of the fetus and she wants to get back at him.' However, the law permits abortions for any reason before viability, not because reasons are irrelevant, but because it would not be feasible to distinguish between acceptable and unacceptable bases for an abortion. Women could easily lie about their reasons, and it would be too intrusive tor physicians to investigate the validity of the woman's explanation. In other words, it would not be possible to implement in practice the principle that a woman must have a morally valid reason for an abortion.
If one believes that abortions are permitted for any reason because one mistakenly thinks the law deems reasons morally irrelevant, one will misunderstand why the law has not qualified the right to abortion before viability in terms of the woman's reasons for choosing abortion." Proper understanding of abortion law requires consideration of both underlying principle and the translation of principle into practice.
In the remainder of this chapter, I will discuss in more depth why generally valid rules are often preferable to case-by-case judgments. I will also indicate how the distinction between physician-assisted suicide and withdrawal of life-sustaining treatment can be better understood in terms of using generally valid rules to accomplish the translation of principle into practice.
