Defending the sexual complementarity between men and women in marriage is an essential first step in building up a healthy "culture of marriage" as a whole, say the authors of a new book.

"I really do believe that this is a reasonable debate among reasonable people of good will," said Prof. Robert George of Princeton University.

George spoke Dec. 19 at the Catholic Information Center in Washington, D.C. Joining him at the promotional event for their book, "What is Marriage," were co-authors Sherif Girgis and Ryan Anderson.

The speakers explained that while attempts to redefine marriage are based on an understanding of the union as primarily emotional, this is neither the historical nor contemporary definition of the marital union.

Girgis, who is both a second-year Ph.D. student at Princeton and a first-year law student at Yale, observed that marriage, historically and philosophically understood, is a conjugal, comprehensive union on multiple levels.

In marriage, there is a "union of heart and mind but also of the body," he said, explaining that the physical realities of husband and wife are integral to the conjugal nature of marriage. 

It is this bodily union that makes procreation possible and distinguishes marriage from friendships and other human relationships, Girgis explained.

Changing marriage from this definition would be harmful to society, and should therefore be avoided, warned Anderson, a fellow at the Heritage Foundation.

He stressed that "being for marriage does not mean anti-gay" and said that marriage defenders "should be at the forefront" of efforts to oppose bullying and discrimination against those who are same-sex attracted.

However, he continued, supporters of marriage should not allow their position to be called "bigotry," and they must explain that their position is not unjustly discriminatory.

Instead, he maintained, supporters of traditional marriage should affirm that there is "(n)othing more important for the future of the nation" than a "healthy marriage culture," particularly for the benefit of children.

Government has a vested interest in protecting and promoting marriage, Anderson said, because of the social benefits offered by a healthy marriage culture.

Outlining the political consequences of redefining marriage, he pointed towards the creation of no-fault divorce and how it has changed society's view of marriage by removing the concept of permanence.

Accepting "gay marriage" would further weaken marriage by removing the understanding that it is a fundamentally conjugal union, he said.

Anderson also noted that if it is "judgmental" to state that children need both a mother and a father, it will become increasingly difficult to promote active fatherhood and could lead to increased fatherlessness across the country.

Concluding the discussion, George asserted that ultimately, the marriage question is one of rationality.

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In a culture that lacks an understanding of the importance of conjugal union, marriage seems to be a mere issue of equality, he explained.

However, the implications of redefining marriage are drastic, he continued, because without the element of sexual complementarity, there is no rational basis for rejecting polyamory.

As a result, redefining marriage could lead to a collapse of the term altogether, he said, noting that many people "can't explain why marriage requires exclusivity and sexual fidelity," as well as permanence.

Promoting the conjugal aspect of marriage is an important step in rebuilding the definition of the institution that has existed in every culture throughout recorded history, George said.

He explained that the strengthening of marriage will require additional efforts, with aid from law, philosophy, culture and religious institutions. 

"The struggle to preserve the conjugal understanding of marriage in our law," George stated, is "only a first step...of the steps we need to take...to rebuild a strong and healthy and vibrant marriage culture."