Tonsure (Lat. tonsura shaving) is a name given to the distinguishing mark of the clergy of the Romish Church, formed by shaving off some of the hair. The custom is said to have been introduced at the end of the 5th century. At an earlier period it was censured as unbecoming spiritual perons, on the ground of its being among the tokens of penance. Albaspinaeus notes "It was customary to use shaving even to baldness, and sprinkling the head with ashes, as signs of sorrow and repentance; but the priests of God were not to be thus treated;" which shows that the ancients then knew nothing of this as a ceremony belonging to the ordination or life of the clergy. The ancient tonsure, therefore, was not a shaven crown, for Jerome, Ambrose, and others, equally inveigh against this as a ceremony of the priests of. Isis; it was only an obligation on the monks and clergy to wear decent and short hair, as is evident from all the canons that appoint it. The tonsure in early times was called corona clericalis, and the clergy coronati, not, however, from their shaven crowns, but from the form of the ancient tonsure, which was made in a circular figure by cutting away the hair a little from the crown of the head and leaving a circle hanging downwards. At first the lowest church servants wore their hair short as a mark of servitude, and the monks, out of humility, imitated them, and in the 6th century the clergy adopted the fashion.
The form of the tonsure varied in different churches, and the varieties of it are of some historical interest. That of the Roman Church, called the "Tonsure of Peter," consisted of shaving the crown as well as the back, of the head, so that there remained a circular ring or crown of hair. This was the form in use in Italy, Gaul, and Spain; In, the Scottish (or Irish) tonsure, which was in use in Ireland, in North Britain, and those parts of Germany in which the Irish missionaries had preached, the entire front of the head was shaved, leaving it bare as far back as the line from ear to ear. This tonsure was called "the tonsure of James," and sometimes of "Simon the Magician." The Greeks and other Orientals shaved the whole head. The supposed derivation of the Irish form of tonsure from the apostolic tires led to its being held both in Ireland and Britain, as well as other churches of Irish foundation, to be of the most vital importance, insomuch that the introduction of the Roman form was almost the occasion of a schism.
As to the signification of the tonsure, the catechism of the Council of Trent says that it was intended to signify that the ministers of religion are in all things so to comport themselves as to carry about them the figure and likeness of Christ. Anthony, archbishop of Florence, says, "The shaving on the upper part of the head signifies that they ought to have a mind free for the contemplation of divine things. The tonsure over the ears denotes that they ought not to have dull senses, or be involved in worldly matters, which are designated by the hair. But the cut of the hair in form of a circle designates the royal dignity which they have and because they ought to regulate themselves and others according to the virtues." The circle formed at the back of the head by the tonsure is enlarged as the person rises in ecclesiastical dignity. Originally the tonsure was merely a part of the ceremonial of initiation in orders, and was only performed in the act of administering the higher order but about the 7th century it came to be used as a distinct and independent ceremonial; and a question has been raised whether it is to be considered in itself as an order, and to be added to the list of what are called "minor orders." The now received opinion of Catholic writers is that tonsure is not an order, but only a preparation for orders. Concealment had already been forbidden in Edgar's canon, and by Anselm, in 1102; and Peckham, in 1281, complains that the clergy covered it out of sight with hair laces. See Bingham, Christ. Antiq. bk. 6:ch. 4:§ 16, 17; 7:3, § 6; Walcott, Sac. Archceöl. s. lt. Wetzer u. Welte, Kirchen-Lex. s.v.