Lay brothers have been known, in various places and at various times, as fratres conversi, "converse brothers," laici barbati, illiterati, or idiotæ. These last two stem from the fact that in previous centuries, lay brothers were often not well educated, or even literate, and therefore unsuitable for studies leading to life as a choir monk or priest (in some orders, all choir monks are actually also priests). Thus, with skills as carpenters or cooks, but without the ability to read the psalms to be sung during the Divine Office, lay brothers lived and worked in their own section of the monastery grounds, participated in simplified prayer services or attended the prayers of the choir monks, and spent a greater part of their day engaging in their skilled trade or unskilled labor.
With literacy much wider today, most lay brothers can read, but either do not have the inclination or talent to undertake advanced theology studies, or have chosen the lay brother's life for other reasons.
No such distinction existed in early Western monasticism. The majority of St. Benedict's monks were not clerics, and all performed manual labor, the word conversi being used only to designate those who had received the habit late in life, to distinguish them from the oblati and nutriti. But, by the beginning of the 11th century, the time devoted to study had greatly increased, thus a larger proportion of the monks were in Holy Orders, even though great numbers of illiterate persons had embraced the religious life. At the same time, it was found necessary to regulate the position of the famuli, the hired servants of the monastery, and to include some of these in the monastic family. So in Italy the lay brothers were instituted; and we find similar attempts at organization at the Abbey of St. Benignus at Dijon, under William of Dijon (d. 1031) and Richard of Verdun (d. 1046), while at Hirschau, Abbot William (d. 1091) gave a special rule to the fratres barbati and exteriores.
At Cluny the manual work was relegated mostly to paid servants, but the Carthusians, the Cistercians, the Order of Grandmont, and most subsequent religious orders possessed lay brothers, to whom they committed their secular cares. At Grandmont, indeed, the complete control of the order's property by the lay brothers led to serious disturbances, and finally to the ruin of the order; but the wiser regulations of the Cistercians provided against this danger and have formed the model for the later orders. In England, the "Black Monks" (Benedictines) were reported by some writers to have made but slight use of lay brothers, finding the service of paid attendants more convenient. Thus Father Taunton asserted that, "in those days in English Benedictine monasteries there were no lay brothers." On the contrary, however, they are mentioned in the customaries of the Abbey of St. Augustine at Canterbury and the Abbey of St. Peter at Westminster.
Lay brothers are usually distinguished from their brethren by some difference in their habit: for instance, the Cistercian lay brother wears a brown tunic, instead of white, with the black scapular; in choir they wear a large cloak, instead of a cowl; the Vallombrosan lay brothers wore a cap instead of a hood, and their habit was shorter; the English Benedictine lay brothers wear a hood of a different shape from that of the choir monks, and no cowl; a Dominican lay brother wears a black, instead of a white, scapular. In some orders they are required to recite daily the Little Office of Our Lady, but usually their office consists of a certain number of Paters, Aves, and Glorias. Wherever they are found in considerable numbers they possess their own quarters in the monastery; the domus conversorum is still noticeable in many of the ruins of English monasteries.
They, too, are distinguished by their different habit from the choir sisters, and their Office consists of the Little Office of Our Lady or a certain number of Paters, etc. They seem to have been instituted earlier than the lay brothers, being first mentioned in a life of St. Denis written in the 9th century. In the early medieval period we even hear of lay brothers attached to convents of women and of lay sisters attached to monasteries. In each case, of course the two sexes occupied distinct buildings. This curious arrangement has long been abolished.
The changes brought about by the Second Vatican Council included the call to all religious orders to re-examine and renew their origins. As a result, most of the distinctions noted above, in terms of dress and spiritual regimen were abolished or mitigated. While some continue to be known as Brothers, all members of a religious order now have equal rights and wear the same habit.