Doctrine of double effect
What it means
An action with a good intended effect (relieving suffering) is permissible even if it has a foreseen but UNINTENDED bad effect (hastening death), provided the intention is the good effect and the bad effect is proportionate. It distinguishes giving adequate opioids/sedation to relieve terminal distress (lawful) from administering a drug INTENDING to kill (unlawful euthanasia).
Worked example
Titrating morphine to control a dying patient's pain, which may also shorten life slightly, is lawful — the intention is symptom relief, not death.
In the exam
A dying patient needs escalating opioids for pain; the doctor gives them to relieve suffering, accepting they may marginally hasten death.
What settles it
Lawful when the INTENTION is symptom relief and the dose is proportionate; giving a drug with the intention of causing death is unlawful (euthanasia).
Classically confused with
Withholding vs withdrawing treatment
Source: Doctrine of double effect