Final answer:
The Double Effect Principle justifies the risk of harm in administering larger doses of morphine to relieve the pain of a terminally ill patient.
Step-by-step explanation:
The principle that justifies the risk of harm in this situation is the Double Effect Principle. This principle is based on the idea that a morally good action can have both a good effect and an unintended bad effect, as long as the bad effect is not intended and is outweighed by the good effect.
In this case, the nurse is administering larger doses of morphine to relieve the patient's pain, which is the good effect. The unintended bad effect of inhibiting respiration is justified because the relief of pain is considered more important in this situation.