There is a fascinating section in the autobiography of Saint Therese of Lisieux where she recounts her stint as novice mistress in the Carmelite convent. She saw the absolute necessity for sometimes employing a ‘cold face’:
"I have said that I learned a lot by teaching others. I discovered that every soul has almost the same difficulties and that there is yet a vast difference between individual souls – a difference which means that each one must be dealt with differently. There are some with whom I must make myself small and show myself willing to be humiliated by confessing my own struggles and defeats, for then they themselves easily confess their own faults and are pleased that I understand them through my own experience. To be successful with others, firmness is necessary. I must never go back on what I have said, and to humiliate myself would be regarded as weakness.
"God has given me the grace of having no fear of a fight. I will do my duty at any cost."