Chapter 9 allows for strong discipline, but only under a strict condition: the parent’s concern must be greater than the severity of the punishment. Correction becomes destructive when the child feels the force more than the love behind it.
That makes the real issue not whether discipline exists, but whether it remains enclosed inside unmistakable affection. If love outweighs severity, correction can still be received as formation. If severity outweighs love, resentment is more likely than repentance.
This turns discipline into a question of moral atmosphere rather than technique. The child has to experience that the relationship is larger than the moment of pain.