V A R I O U S reasons have been assigned for the sudden decision of Luther to become a monk. The real cause lay in a torturing sense of sin and a longing for reconciliation with God, experienced by many deeply spiritual Christians at one time or another in their lives. The cloister had been the refuge of such persons for a thousand years; to it the Saxon student naturally turned to find rest for his soul. After all, the seemingly abrupt vow is only the natural culmination of previous experiences. The strict discipline of a stern and pious home, the terrible vision of the begging prince, the priestly circle of friends at Eisenach, had all pointed the boy to the career then regarded as the perfection of Christianity.