Laurence Tribe sets out to do the all but impossible here: find common ground between the opposing sides of the abortion conflict. A professor of constitutional law at Harvard, Tribe is accustomed to picking his way through the murky overgrowth of law, politics, religion and emotion that characterizes issues of private conduct and public policy. His detailed, wide-reaching analysis of the abortion debate is not difficult to read–clarity is the main virtue of his prose style–but the more we learn, the more clearly we see why Tribe’s stated goal is going to elude him.

Willing though he is to criticize both camps, Tribe makes it plain he supports most of the reasoning behind Roe v. Wade, the 1973 Supreme Court decision affirming a qualified right to abortion on the basis of the right to privacy. He admonishes some pro-choice advocates for language that insults their opponents, but his scrutiny of the anti-abortion position predominates–a focus illuminating that side of the argument often obscured by rhetoric and extreme tactics. We already know the realworld consequences of Roe: safe, early abortions are widely available; patients experience few if any lasting effects, and fetuses die. The complications inherent in a law banning abortion are rarely spelled out; and perhaps the major contribution of Tribe’s book is that he does just that.

Fertilized egg: What would happen, for instance, if legislators actually wrote into law the oft-heard call for fetal protection from “the moment of conception”? In effect Tribe summons a cell biologist to the witness stand, who explains that a fertilized egg contains the genetic material necessary to form a human being but that the unique physical characteristics of that person will be determined only in the course of gestation. Most people, Tribe notes, intuitively resist equating the early loss of embryonic life–whether by miscarriage or an abortifacient birth-control device like the IUD–with the death of a baby.

Under a law explicitly mandating a right to life from the moment of conception, however, even early abortions would be crimes tantamount to murder. Some forms of birth control would be outlawed; in vitro fertilization could be banned because some fertilized eggs are destroyed, and a host of other legal nightmares would be set loose. As Tribe writes, “The idea that the Constitution protects fetuses just as if they had already been born seems . . . impossible to maintain without accepting consequences for which no one seems willing to argue.”

Tribe is especially critical of abortion laws designed as compromises, for instance those compelling minors to notify their parents. Minors on good terms with their families talk to them anyway, Tribe points out; only when children resist telling their parents does the law intrude. Last year a 13-year-old Idaho girl pregnant by her father had to notify him; he shot her to death. Many such laws allow minors to bypass the requirement by going to court, but the delay and intimidation help nobody, including the fetus. Similarly, he views laws permitting abortion only for victims of rape or incest as more hypocritical than compassionate. Since the fetus is innocent in both cases, the purpose seems to be to distinguish between women who are blameless and women who are guilty–but of what?

For many readers, the overwhelming message of Tribe’s book may be one that he didn’t intend: no matter which side you take, the law is the wrong vehicle for this issue. Our beliefs about abortion are profound, complex and inconclusive–closer that is, to beliefs about religion than to law, politics or cell biology. Government respects such beliefs best by stepping aside for them.