Gregory the Dialogist : They are rightly called priests who are set over the faithful for giving them sacred guidance. But hairs outside the head are thoughts in the mind, which, as they spring up without notice above the brain, denote the cares of the present life, which sometimes come forth unseasonably, due to negligent perception, since they arise without our feeling them. Because all who are over others ought indeed to have external anxieties, and yet should not be overly concerned about them, priests are rightly forbidden either to shave their heads or to let their hair grow long. This means that they may neither cut themselves off entirely from thoughts of the flesh for the life of those who are under them, nor again allow such thoughts to occupy them too much. — PASTORAL RULE 2:7