The pope remained consistent with his previous days as prefect of the Congregation for the Doctrine of the Faith in an address at the Basilica of St. John Lateran before a conference of the Diocese of Rome on the role of the family. For the first time since his election, Pope Benedict XVI condemned publicly same sex unions.
He also took the occasion to reiterate the church's opposition to abortion.
He said matrimony was not just a "casual sociological construction" that changed in certain times in history but rather an institution that had its roots "in the most profound essence of the human being."
"The various forms of the dissolution of matrimony today, like free unions, trial marriages and going up to pseudo-matrimonies by people of the same sex, are rather expressions of an anarchic freedom that wrongly passes for true freedom of man," he said.
The Holy Father also echoed Pope John Paul the Great by calling for laws that help families to have children and to educate them.
Children, he said, were the fruit of marriage and reflected God's love for man.
"From here it becomes all the more clear how contrary it is to human love, to the profound vocation of man and woman, to systematically close their union to the gift of life, and even worse to suppress or tamper with the life that is born," he said.
The complete text of the pope's remarks can be found at Zenit (consider a donation).
Benedict XVI on Anthropological Foundation of the Family (Part 1)
Benedict XVI on Anthropological Foundation of the Family (Part 2)