Bishop Robert C. Morlino of Madison said he was "deeply saddened" by a federal ruling that Wisconsin law must recognize "gay marriage," warning that it endangers the family as a fundamental basis of society.

Marriage between a man and a woman is "an element of the very first 'domino' of civilization," the bishop said in a statement.

"When that first 'domino' falls, everything that is good, true, and beautiful, which is rooted on the natural family, is seriously threatened."

"There can be no question that the best formation for children is in the home of their biological mother and father, generally speaking, and we should always have a greater concern for future generations than we do for ourselves," he said.

U.S. District Judge Barbara Crabb on June 6 ruled that a Wisconsin law defining marriage discriminates against same-sex couples.

The judge's ruling struck down a referendum passed in 2006 by the majority of voters. The referendum defined civil marriage as a union of one man and one woman and said that legal statuses identical or similar to marriage would not be recognized in the state.

While media reports characterized the Wisconsin law as a "ban," the law did not bar private ceremonies.

Wisconsin Attorney General J.B. Van Hollen said that the original law remains in force and he will appeal the decision.

"While today's decision is a setback, we'll continue to defend the constitutionality of our traditional marriage laws and the constitutional amendment, which was overwhelmingly approved by voters," he said June 6.

Van Hollen filed an emergency stay against the decision June 9, although some county clerks have begun to issue marriage licenses to same-sex couples.

Bishop Morlino emphasized that the fundamental role of marriage, saying, "Marriage is, and can only ever be, a unique relationship solely between one man and one woman, regardless of the decision of a judge or any vote."

"In striking down the constitutional amendment in our state which protects marriage, the court has, once again, shaken one of the most precious and essential building blocks of our civilization," he continued.

The bishop also stressed that Catholics must "respect, love and care for every individual we encounter, regardless of who they are, where they come from, or how they define themselves."

"For my own part, I will continue to speak strongly about the truth and beauty of marriage and encourage my brother priests and deacons, and all the lay faithful, to do the same," Bishop Morlino said, calling for "fervent" prayers.