This article treats of main points in Luther's less known treaty on monastic vows, "De votis monasticis iudicium", from 1521. It is demonstrated how Luther bases his ideas on Bernard of Clairvaux's understanding of monastic life as a Christ-formed life in the faith in God. Luther values that also Bernard stressed how monastic life must be voluntary and its character as only one modus vivendi amongst others, wherefore they also both emphasize that monastic life is not an expression of perfection, not a status perfectionis. Coherently, neither of the two operate with the scholastic differentiation between "praecepta" and "consilia" (Bernard does not know such a differentiation, post his time; and Luther sharply confronts the arrogance he finds in such an epistemology). On the other hand, they have very different views on the raison d'être of monasticism. Bernard, who lives in a flourishing yet turbulent Europe of the11th century, sees the monastery as a sublime greenhouse for growing a social and peaceful life in love of neighbour, which ought to be the ideal of all human life. Luther, living 400 years later, experiences a quite different ecclesial and monastic life, where he witnesses abuse and arrogance rather than devotion and love as factors ruling the everyday live.