In the Service of Human Life
Tree on a hill on a starry night
Applied Bioethics in stylized text
  • © 2019 ChetComm, LLC 0

In the Service of Human Life

Double Effect Explained

In the world of philosophy, there are more than a few heavyweights that hail from the Catholic Intellectual Tradition. These deep thinkers pioneered new ways of approaching life’s great questions. The morality of the Church colors these viewpoints in a way that esteems the human person and seeks its ultimate good. Even non-Catholics will recognize names like Thomas Aquinas, Duns Scotus, Augustine, and the more modern GK Chesterton. What makes their contributions so significant is that, while rooted in faith, they’re broadly applicable. One of these offerings is Aquinas’ Principle of Double Effect.

You may have heard an example of this principle before.You and some friends go exploring in a cave. While trying to leave, one of your friends becomes stuck in the narrow entrance blocking your way. You can’t move them and you’re all trapped inside with no possible escape or rescue coming. Would it be ethical to use the dynamite that you brought along to blow a wider hole, even though it may fatally wound your friend?

It’s not unusual for a single action to have two effects. Hitting a grand slam in the World Series inspires the player who cranked the ball out of the park and demoralizes the pitcher who threw too good of a pitch. The same is true in medicine. A new regimen of prescription drugs for a patient can cure an ailment while at the same time generating some unpleasant side effects. Their seizures may stop, for example, but they may be constantly nauseous.

What happens, though, when one of the effects is a moral good, and the other is a moral evil? How do we ethically parse that scenario in a way that maintains respect for the patient and keeps a medical decision within the boundaries of an ethical code?
Aquinas offers his Principle for just this situation. The Stanford Encyclopedia of Philosophy summarizes Aquinas’ criteria in this way:

- The act itself must be morally good or at least indifferent.
- The agent may not positively will the bad effect but may permit it. If he could attain the good effect without the bad effect he should do so. The bad effect is sometimes said to be indirectly voluntary.
- The good effect must flow from the action at least as immediately (in the order of causality, though not necessarily in the order of time) as the bad effect. In other words the good effect must be produced directly by the action, not by the bad effect. Otherwise the agent would be using a bad means to a good end, which is never allowed.
- The good effect must be sufficiently desirable to compensate for the allowing of the bad effect

In other words, the action being taken must not be morally evil on its own, the person taking the action must intend the good result, the good result must not come from an evil means, and the good result must be proportional.

In order for a decision to have the justification of double effect, all four criteria must be satisfied. Failure on any one point is an ethical failure on the question.

One of the medically acceptable uses of abortion is in cases where the mother’s life is at risk. Thankfully, medical advances have made these situations statistically insignificant. Even still, what about a pregnant woman who is facing a medical condition that threatens her life? She elects to have an abortion. Intending to save her own life, the abortion also has the effect of ending the life of her child. Does the Principle of Double Effect validate her decision as ethical?

Her decision fails all four of the criteria. First, abortion is the intentional act of killing a person. That is neither morally good nor is it indifferent. Second, the bad effect of abortion is inseparably linked to her desire to preserve her own life through the abortion. Third, the good effect is produced solely through the abortion. It’s using evil means to achieve a good, which is unacceptable. Finally, the preservation of the life of the mother is in no way compensation for the death of the child.

Now, if that same mother needed to start a course of treatment not possible while pregnant, she could elect to have her pre-term child delivered by cesarian section and admitted to the Neonatal Intensive Care Unit (NICU). NICU technology has advanced to the point where even a child born at 22 weeks has a chance of survival. If she delivered the child, and started treatment, and her child for whatever reason did not survive, the Principle of Double Effect may validate her decision as ethical. A full analysis would be required, but it’s very possible that her decision was ethical, even if it resulted in a negative outcome.

Patients benefit from a rigorous ethical inquiry into their treatment options. The Principle of Double Effect is among the best tools that any patient, physician, or ethicist can use to choose the right course in a difficult situation.