(Commonweal) Andrew Koppelman reviews “What Is Marriage?Man and Woman: A Defense”

from TitusOneNine by Kendall Harmon

For better or for worse, same-sex marriage is one of the most successful social movements in American history. Its claims were outside the realm of political possibility as recently as the early 1990s. Now its victory is probably inevitable. It has succeeded largely because so many of its opponents have been so inarticulate, and—this is crucial—have failed to pass on their views to their children. According to Gallup, 46 percent of Americans oppose same-sex marriage, with 53 percent in favor. The percentage in support has doubled in only fifteen years. There is a sharp generational divide: among those eighteen to twenty-nine-years-old, 73 percent support same-sex marriages. That number drops steadily with age, to 39 percent of those 65 and older. The result has been a massive political shift. Barack Obama is the first Democratic president to support same-sex marriage. He is also the last Democratic president to oppose it. The Republicans have begun, painfully and grudgingly, to do likewise.

So What Is Marriage? is an important book. It is clear, tightly reasoned, and a remarkably fast read for a dense philosophical argument. It should be instantly recognized as the leading statement of the case against same-sex marriage, together with Maggie Gallagher’s half of Debating Same-Sex Marriage (coauthored with John Corvino). Gallagher’s strategy is consequentialist, turning on baleful but improbable predictions about the effect of same-sex marriage on heterosexual familes. The authors of What Is Marriage?, on the other hand—Sherif Girgis and Ryan Anderson are unusually bright graduate students, and Robert P. George is the McCormick Professor of Politics at Princeton—are proponents of the New Natural Law theory, a philosophical school whose leaders are the Catholic scholars Germain Grisez and John Finnis....

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