In this paper the author tries to present the reflection that make Juan de la Pefia and Martin Luther about monastic vows. The issue is particularly interesting, especially because the existence of votes in the religious life has been one of the main points of contention between the traditional scholastics and the new protestants. The importance of this topic shows also in the discussion on the power of the Church to determine the faith and morals in the matters that the divine right has been silent.