The 84-year-old pope acknowledged his comments might sound anachronistic or "countercultural," particularly to the young. But he told bishops to not back down in the face of "powerful political and cultural currents seeking to alter the legal definition of marriage."

"Sexual differences cannot be dismissed as irrelevant to the definition of marriage," he said...

Benedict said a weakened appreciation for traditional marriage ... had led to "grave social problems bearing an immense human and economic cost." He didn't elaborate on what the cost was. [Emphases mine]