Many Americans who believe that women should be able to choose when and whether to bear a child are also deeply disturbed by the one-and-one-half million abortions performed each year in this country. They regard these concerns as irreconcilable, because the topic of abortion, until now, has been framed as a black-or-white conflict between the rights of the mother and those of the fetus. The very idea of compromise or common cause draws scorn among factions. How, after all, can the political debate about abortion permit any more options than pregnancy itself does? This extraordinary book...