VATICAN CITY, NOV. 28, 2010 ( Benedict XVI is affirming that life, once conceived, "must be protected with the greatest care."

The Pope pronounced these words Saturday while presiding at vespers for the first Sunday of Advent in St. Peter's Basilica.

The liturgy was preceded by a Vigil for All Nascent Human Life, which was promoted by the Pontiff on Nov. 14.

This vigil was also observed in union with the Holy Father in parishes, communities, movements and associations throughout the world.

"Experience and right reason," Benedict XVI said, "attest that the human being is a subject capable of understanding and willing, self-conscious and free, unrepeatable and irreplaceable, the meeting point of all terrestrial realities, that demands to be recognized as a value in himself and merits always being welcomed with respect and love."

The Pope continued: "He has the right not to be treated as an object to be possessed or as a thing that can be manipulated at will, not to be reduced to a pure instrument for others' advantage and interests.

"The person is a good in himself and his integral development must always be sought."

Furthermore, the Pontiff observed, "love toward all, if it is sincere, tends to become preferential attention for the weakest and the poorest."

In the womb

"In regard to the embryo in the maternal womb," he said, "science itself provides evidence of its autonomy, capable of interaction with the mother, the coordination of biological processes, the continuity of development, the growth in the complexity of the organism."

"It is not a matter of an aggregate of biological material," the Holy Father asserted, "but of a new living, dynamic and marvelously ordered being, a new individual of the human species."

"This is how Jesus was in Mary's womb," he added. "This is how it was for each of us in the mother's womb."

The Lord's incarnation and the beginning of human life, in fact, are intimately connected, Benedict XVI pointed out.

He explained that the former reveals that every human life has an "incomparable dignity," to which the "great responsibility toward all" is linked.

The Pope noted that, unfortunately, even after birth the lives of many children continue to be exposed to abandonment, hunger, misery, sickness, abuse, violence and exploitation.

He called on politicians, economists and the mass media to promote a culture that is ever more respectful of life.

Reciting the prayer for life at the conclusion of the celebration, the Pontiff invoked the Creator's protection of children, spouses, of all those who suffer from the impossibility of having children, and of orphans.

He asked for the light of the Holy Spirit to be shed on the decisions of legislative assemblies and the work of scientists and physicians, so that progress will contribute to the integral good of the person.