If his health holds out, Pope John Paul II will travel to Mexico later this month to confer sainthood on Juan Diego, a peasant to whom the Virgin Mary reportedly appeared in 1531. For some, it will be a dream come true—finally, the large Catholic population in Latin America will have its own indigenous saint. For others, though, the dream is soured by the knowledge that Juan Diego may be a figment of fantasy, or worse, propaganda.

In the early sixteenth century, Spanish Conquistadors labored to convert native Mexicans to Catholicism. The Spanish managed to overthrew Mexico's Aztec rulers in 1521 but continued to battle resistance to Spanish culture and religion. Then, according to the oral history on which the Vatican is basing the canonization, Mary appeared to Juan Diego and told him she wanted a shrine. To reinforce the message, Juan Diego was given a cloak that was originally full of flowers but later unfolded to reveal a beautiful image of Mary.

Unfortunately, a church-appointed expert has deemed the cloak a fraud. He says that Mary's image was painted by humans, not illustrated by a divine hand. Furthermore, accounts of Juan Diego's exploits date from 200 years after his death and were handed down by church officials who had a vested interest in proving that Catholicism and Mexican heritage can be blended. Still, to the Vatican (which retains that interest in linking Catholicism and Mexican heritage, especially in the face of challenges from Pentecostalism and secularism), the evidence is good enough. As John Paul has said, Juan Diego is "an example for all of the faithful: He teaches us that all the followers of Christ, of whatever condition or state, are called by the Lord."

The exemplary role of saints has trumped ...