The Pope's explanation was heard Saturday by some 700 doctors, scientists, philosophers and theologians, who gathered in the Vatican to take part in a three-day conference organized by the Pontifical Council for Health Care Workers on "The Human Genome."

"The people of our time," the Holy Father said, "sensitized by the terrible vicissitudes that have covered the 20th century and the very beginning of this one in mourning, are able to understand that man's dignity is not identified with his DNA genes and that it does not diminish with the eventual presence of physical differences or genetic defects."

In his Italian-language address, Benedict XVI said: "The principle of 'non-discrimination' in virtue of physical or genetic factors has entered profoundly in consciences and is enunciated formally in the charters on the rights of man."

Quoting the first chapter of Genesis, he affirmed: "This principle has its most authentic foundation in the very dignity of every human being by the fact of having been created in the image and likeness of God."