During the summer of 2000, my family and I enjoyed the privilege of traveling to Mexico. We visited my older brother, who worked in Guadalajara at the time, and vacationed with his family. We made a pilgrimage to the birthplace of my paternal grandfather and to the Shrine of Our Lady of Guadalupe.

The Basilica at Guadalupe, where the miraculous image of Mary hangs behind the altar, is a round, modern structure fronted by an expansive courtyard. An older church sits to one side. Behind that second church is a hill, named Tepeyec, the place where Mary first appeared to Juan Diego. A system of steps and ramps, rising between stone fences and under numerous iron trellises filled with roses, allows pilgrims to ascend to the spot of the apparition. At the summit is a small chapel, featuring from its front steps a grand view of Mexico City and the Basilica below.

A year before our pilgrimage, Pope John Paul II celebrated Mass at the Shrine, which he called “the Marian Heart of America.” In his homily, he prayed for the Virgin of Guadalupe’s intercession in the American hemisphere: “May the Continent of Hope also be the Continent of Life! This is our cry: life with dignity for all!”

The story of Mary’s appearance before St. Juan Diego epitomizes the meaning and significance of human dignity. She showed herself as a “mestiza,” with the blended coloring of a Native American and European mixed heritage. As explained by Pope John Paul II in another address in 2001, her features symbolize for us all that all people are brothers and sisters.

She spoke to a man who was born an Aztec and later baptized as a Christian, talking to him in the words of his own language. Standing near the site of a temple where human sacrifice was practiced, she identified herself as the Mother of the “True God,” the only Divine Being “who gives life and maintains it,” and who “is Lord of Heaven and Earth.”

She promised Juan Diego, and through him an entire native culture, to share her compassion and consolation in the face of suffering, thus eliminating forever the urge to appease false gods through the sacrificial slaughter of innocent lives.

Nowadays a new form of human sacrifice has arisen to combat suffering, not as an attempt to placate the gods, but as an effort to assume the role of gods. Scientists are conducting experiments that depend on the destruction of human life. They are also performing procedures in the laboratory that substitute for the personal intimacy of husband and wife, thus turning procreation into manipulation.

On the Feast of Our Lady of Guadalupe in 2008, the Vatican’s Congregation for the Doctrine of the Faith issued a new document addressing the latest developments in medicine and science.

The “Instruction Dignitatus Personae on Certain Biomedical Questions” reiterates the Catholic Church’s concern for human dignity at all stages of life, commends scientists who are achieving great good without resorting to practices which offend that dignity, and offers guidance on the ethics of new therapies and procedures.

The document stresses the importance of respecting human dignity as an intrinsic and inviolable feature of human existence, thus implicitly responding to calls heard recently in some quarters to abandon the concept of dignity.

For example, Stephen Pinker wrote an article published last spring in “The New Republic” magazine called “The Stupidity of Dignity.” Pinker, a psychologist and science commentator, alleged that refraining to do research out of a concern for offending human dignity “flaunts a callousness towards the billions of non-geriatric people, born and unborn, whose lives or health could be saved by biomedical advances.” He contended that “A free society disempowers the state from enforcing a conception of dignity on its citizens.” He ridiculed those who espouse what he called “an obstructionist bioethics.”

In the conclusion to its recent bioethics instruction, the Congregation for the Doctrine of the Faith acknowledges that “There are those who say that the moral teaching of the Church contains too many prohibitions.” The Congregation replies by listing a series of legal, medical and ethical abuses in history that have prompted renewed pleas from across the secular spectrum to respect human dignity.

The Congregation then puts the issue squarely: “Behind every ‘no’ in the difficult task of discerning between good and evil, there shines a great ‘yes’ to the recognition of the dignity and inalienable value of every single and unique human being called into existence.”

During the days of Christmas and the beginning of the New Year, let there be among us a renewal of our yes to life and a recommitment to cherishing human dignity.

Daniel Avila is the Associate Director for Policy & Research of the Massachusetts Catholic Conference