|Crosses and Crucifixes
The difference between a cross and a crucifix is that the latter bears a "corpus" or image of Christ's body. Sometimes a museum will display the corpus only, the cross having been lost (example). In the first centuries A.D., the anchor symbol sometimes served as an alternative to the cross as an identifier of Christianity, because of its cross-like shape and also because of the Letter to the Hebrews' declaration that the hope in God is "an anchor of the soul" (6:19)
In the earliest crucifixes, starting with the seventh century, the corpus is dressed in a colobium and its outstretched arms do not bend with the weight of the body (example). Straight and firm as they are, the arms can suggest welcome or acclaim by a victorious leader.
From the 10th through the 12 centuries the colobium is gradually replaced by a loincloth (example) and there is an ever greater emphasis on the pathos of the Christ's death. From the 12th century forward the arms stretch more with the weight of the body, and one can see the wound in Christ's side (example). An interesting example in Spain has the old triumphal version on one side of the cross and the new loincloth version on the other. Late medieval crucifixes often emphasized the torments Christ suffered, with very literal detailing of his wounds and bruises; this emphasis continued into Counter-Reformation art (example) and thence to the folk art of Latin countries, where it is still in evidence (example).
At the top of the vertical crosspiece one often sees a scroll bearing the letters INRI, which stand for Iesus Nazarenus Rex Iudeorum, "Jesus of Nazareth, King of the Jews." The Roman practice was to use such a scroll to identify the criminal and his crime (see John 19:19-22). On larger crucifixes the scrolls will sometimes have the entire inscription (example).
Christian writers of the period of the persecutions mention a sedilus excessus in Christ's cross, a projection functioning as a small seat to keep the weight of the body from pulling the hands off the nails. This feature was never represented in the art, but many crucifixes have a suppedaneum, a sloping ledge to support Christ's feet (example). This is mentioned in Gregory of Tours' Glory of the Martyrs (6th century).
Some 16th and 17th century crucifixes use a skirt rather than a loincloth (example).
Debunkers will sometimes declare that nails could not have been driven through Christ's palms as shown in crucifixes, because of the pull of the body. But the usual Roman practice, well attested in the literature, was to tie the limbs to the cross and then drive nails through the hands and feet. The earliest known Christian image of the crucifixion, from a time not long after the era of public crucifixions, clearly shows nails driven through the palms.
A crucifix made for a liturgical procession is called a "processional cross." There may be secondary images of saints on the ends of the crosspieces (example) or flanking them (example). Holy Week processions in Latin countries feature life-size crucifixes; some churches will keep such a crucifix in a display case during the rest of the year (example) or place the corpus in a glass-sided coffin (example).
Before the modern age it was common in Catholic countries to maintain crucifixes at public crossroads for the edification of travelers, and some of these are still extant today. They are known in Spain as cruceiros (example) and in France as Calvaires (example).
Some crucifixes are the object of special veneration, such as the Señor de Esquipulas in Guatemala and Nuestro Señor de los Milagros in Peru.
For an extensive scholarly treatment of this subject, see the article in the Catholic Encyclopedia.
The cross will sometimes represent the person of Christ in his role as savior of mankind. See the apse mosaic at St. John Lateran and the apsidal arch at Santa Maria Maggiore. A mosaic similar to the Lateran's but with a crucifixion scene instead of a cross is in the apse of San Clemente, also in Rome.
Similarly, the Cross represents the person of Christ exalted on high in domes (example) and most notably in the vault frescoes of the churches of Gesù and San Ignazio in Rome.
Feast of the Exaltation of the Cross: September 14
At left, crucifix by Donatello
Manuel Castillo Fernandez, pilgrims' crucifix
The Cloisters Cross (12th century)
A Spanish crossroads cross
Painted crucifix from Spain
Calvaire in France