Question:What is the Principle of Double
The principle of double effect (PDE) has its roots in the medieval natural law tradition. Its most famous
proponent was Thomas Aquinas in the 13th century. PDE is offered as a tool for distinguishing, on a principled
moral basis, between acceptable and unacceptable acts that have both a good and a bad outcome. The essential
elements that must be established under PDE in order for such an act to be morally acceptable are the
Question: What relevance does PDE have to
the practice of medicine?
Two areas in which PDE has frequently been invoked in contemporary medical practice are abortion and
care of the dying. In a case in which the cancerous uterus of a pregnant woman must be removed to save
her life, PDE has been invoked so as to permit the procedure on moral grounds. Although it results in
a manifestly bad outcome, the death of the fetus, that death is only a foreseeable consequence, rather
than the purpose of the procedure. By contrast, if a craniotomy were to be performed on the fetus in order
to save the life of the pregnant woman, PDE would not allow the procedure because the bad result (the
death of the fetus) must be intended, or at least deemed to be the means by which the good outcome (preserving
the life of the pregnant woman) is brought about.
The relief of pain, suffering, and distress in the dying patient by means of high doses of analgesics
has proven to be another favorite of PDE devotees. If the patient"s imminent death is hastened incident
to the administration of necessarily high doses of opioids or other medications for pain and symptom management,
then PDE condones such conduct. If, however, high doses of analgesics are administered for the express
purpose and with the specific intent of ending the patient"s life (and thereby relieving the patient"s
suffering), then PDE precludes such conduct. The former is deemed appropriately aggressive palliative
medicine; the latter is considered to be a form of euthanasia.
Question: What is the view of contemporary
bioethics with regard to PDE?
PDE has its staunch defenders and its harsh critics among contemporary bioethicists and moral philosophers.
When the Supreme Court of the United States invoked PDE in its opinions in the physician-assisted suicide
cases in 1997, it provoked a renewed flurry of discussion of PDE. Proponents touted it as a guide to the
perplexed in resolving certain "hard cases" in medical ethics. Opponents seized upon the long history
of criticism of PDE in moral philosophy. For example, the third and fourth elements of PDE illegitimately
presuppose certain value judgments, as well as a (nonexistent) consensus upon the relevant values and
how they inform any particular case.
Consider the case of the relief of suffering for the imminently dying patient. Some physicians, and more
importantly some patients, do not consider a hastened death to be a "bad" outcome in the face of otherwise
intractable suffering in the end stages of a fatal condition. With regard to the second element, critics
of PDE emphasize two important points. First, the intentions of clinicians are intrinsically complex,
multifaceted, and ambiguous in such cases. They resist being conveniently simplified and categorized
in the way that PDE does. Second, the law (the Supreme Court"s decisions in the physician-assisted suicide
cases to the contrary notwithstanding) has traditionally postulated the presumption that every person
of sound mind intends the natural and probable (i.e., foreseeable) consequences of her actions. From that
perspective, there is no principled moral distinction between the consequences of one"s actions that
are intended and those that are merely foreseen.
To say this is not to suggest that critics of PDE oppose, for example, either abortion or aggressive
pain and symptom relief for dying patients. It simply means that they apply other strategies of ethical
analysis to defend their positions on either or both of those controversial issues. Ultimately, however,
the search for an overwhelming consensus in support of PDE among bioethicists would be an elusive and
ultimately frustrating one.