Many and varied are the ways in which our saintly forefathers laid down how everyone, whatever his station or the kind of religious observance he has chosen, should live a life of allegiance to Jesus Christ — how, pure in heart and stout in conscience, he must be unswerving in the service of his Master.
It is to me, however, that you have come for a rule of life in keeping with your avowed purpose, a rule you may hold fast to henceforward; and therefore:
The first thing I require is for you to have a prior, one of yourselves, who is to be chosen for the office by common consent, or that of the greater and maturer part of you; each of the others must promise him obedience — of which, once promised, he must try to make his deeds the true reflection — and also chastity and the renunciation of ownership.
Saint Albert of Jerusalem
The Carmelite Rule, Chapters 2-4