SIDNEY CALLAHAN AND DANIEL CALLAHAN This book, like many other things to do with abortion, is a product of long controversy. Though carried out with cooperation, it was conceived in conflict. The conflict between the coeditors has per sisted for years-in fact, for at least half of their thirty-year marriage. One, Sidney, is prolife; the other, Daniel, is prochoice. Ever since the topic of abortion became of professional interest to us, in the 1960s, we have disagreed. At one time, while Daniel was writing a book on the subject, Abortion: Law, Choice and Morality (1970), we talked about the subject every day for the four years of the book's gestation. On many occasions during the 1970s, prolife articles writ ten by Sidney were passed out at Daniel's lectures in order to refute his pro choice views. Over the years, every argument, every statistic, every historical example cited in the literature has been discussed by the two of us. As Eliza Doolittle says about "words" in My Fair Lady, "There's nota one I haven't heard. " And yet we still disagree. How can it be, we ask ourselves, that intelligent people of goodwill who know all the same facts and all the same arguments still come down on different sides of the con troversy? As we well know, it is possible to agree about many things and have great love and respect for an opponent, and still differ.