There have always been lay brothers in the charterhouse. When Saint Bruno retired to the Chartreuse, two of his companions were secular ones: Andrew and Guerin. They also live a life of solitary prayer and join in the communal prayer and mass in the chapel. However, the lay brothers are monks under a slightly different type of vows and spend less time in contemplative prayer and more time in manual labour. The lay brothers provide material assistance to the choir monks: cooking meals, doing laundry, undertaking physical repairs, providing the choir monks with books from the library and managing supplies. The life of the brothers complements that of the choir monks, and makes the fathers' lives of seclusion possible.