Pope Benedict XVI on Tuesday condemned same-sex unions as anarchic "pseudo-matrimony" and reaffirmed the Catholic Church's opposition to abortion.
Benedict repeatedly referred to marriage as a union between man and woman in an address to a conference of the Diocese of Rome on the role of the family held at St. John Lateran basilica.
He said matrimony wasn't 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 Vatican defines matrimony as a divine union between man and woman.
Benedict, the former Cardinal Joseph Ratzinger, spearheaded a campaign by the Vatican against same-sex unions in 2003, issuing guidelines for Catholic politicians to oppose laws granting legal rights to gay couples when he was prefect of the Congregation for the Doctrine of the Faith.