Principle of Double Effect

One

Daniel and the Lion’s Den

In the book of Daniel, several of Daniel’s enemies invent a law just for the sake of getting Daniel in trouble. They say that anyone who prays to anyone other than the king will be thrown into a den of hungry lions. Daniel knows about this law. But he prays to the Lord God anyway as he always does. And, as might have been expected, he gets thrown into the lions’ den. 

Now, obviously getting thrown into the lions’ den is a bad thing. It’s a bad thing physically for Daniel and a bad thing morally for the people who have him tossed in there. Of course, we all know the story, we all know that God rescues Daniel in a miraculous way.

But how can it be legitimate for Daniel to knowingly act in a way that’s foreseen to have such undesirable consequences? 

The answer is what Catholic moral theologians have called “The Principle of Double Effect.”

Two

The Principle of Double-Effect

The principle of double effect says that it is sometimes morally permissible to do something that is foreseen to have undesirable consequences.

The Catechism of the Catholic Church gives two examples of times where you do something that has consequences you anticipate but don’t want.

“An effect can be tolerated without being willed by its agent; for instance, a mother’s exhaustion from tending her sick child. You are not responsible for a bad effect if you did not choose it either as an end or as a means of an action…”

So a mom knows that taking care of her sick child will wipe her out, and even though she’d rather not get exhausted, she’s still right to do the thing that will leave her exhausted.

And there was a seminarian in Witchita not too long ago that, when the group’s boat flipped in the rapids, gave his life jacket to another person who didn’t have hers. She lived and he didn’t, even though he surely didn’t want to die. These actions, like Daniel’s, were good, and even heroic. 

But if you’re going to do something that will very likely end in undesirable consequences, if you’re going to invoke the principle of double effect, then there are certain conditions you have to meet.

Three

Four conditions for the Principle of Double-Effect to be valid

The principle of double-effect doesn’t justify going around doing any action that’s foreseen to have bad consequences. 

For your action to be justified by the principle of double effect, you have to go through the basic tests for a good act we’ve already talked about. 

First, what you’re doing has to be okay. The principle of double-effect is about sometimes accepting bad consequences, not evil actions. So you can’t use the principle of double effect to justify any intrinsic evils: murder, or abortion, or suicide or fornication.

Second, why you’re doing it has to be okay. That means you can’t be motivated by the foreseen bad effect. If Daniel had prayed because he wanted to commit suicide by lion, that wouldn’t have been legitimate. So the bad effect has to be unintended. 

Thirdly, the circumstances should be suitable. In practice, that means that the good consequences of your action should likely outweigh the bad consequences of your action. 

Of course, no one knows what the future holds, but to do something that will likely have bad consequences only makes sense if you think that your action will likely bring about a greater good overall. 

The fourth condition is this: don’t choose an action with bad consequences if you can get the same benefit from a different action without the bad consequences.

If somebody throws a grenade and it would be just as easy for you to pull yourself and the other person in danger behind some protective wall, in that case don’t dive on the grenade to save your friend. Just do the thing that saves you both. 

In other words, don’t be a hero unless you have to. Don’t make needless sacrifices. The principle of double effect is about when sacrifices need to be made. Not when they don’t. 

Four

Medical Cases 

Situations arise, particularly in the medical field, when the principle of double effect becomes very important. 

There are times when you have to make choices that will lead to undesirable results but as long as you aren’t bringing those results about directly, as long as you don’t will those results, and as long as there doesn’t seem to be a better option the Church allows us to make those choices.

So, for instance, in the case of a painful and terminal illness, the Church does not allow euthanasia. It is not okay to kill someone or directly shorten their lives. But it can be okay to give the patient strong painkillers. You can even give doses that may shorten the patient’s life, as long as shortening their life is an undesired side effect. Your motivation in giving someone palliative care has to be simply to lessen the suffering, your goal can’t be to lessen the suffering by killing the patient.

So too, the Church doesn’t allow men to sterilize themselves. It doesn’t allow us to directly attack our own fertility or capacity for fatherhood. But if a man has a cancerous prostate that needs to be removed, it can be legitimate to remove the prostate even if it’s foreseen that the result will be impotence.

Again, the effect isn’t willed as a means or an end. It’s an undesirable effect, but one that can be accepted based on the four conditions we already stated.

Again, the key is to ensure that you’re not doing an intrinsically evil action or have a bad intention. If what you’re doing is okay and why you’re doing it is okay, then, if you really think this will likely bring about the best good overall, you can proceed. 

Five

Doing the Right Thing, Regardless of Foreseen Consequences

The Christian life is full of situations where doing the right thing can lead to undesirable consequences. And this happens mostly in the realm of broken relationships.

Following Christ often results in alienation from others. Which is no surprise: He promised that it would. So, for instance, converting to Catholicism can have the undesirable consequence of outraging anti-Catholic family members. The decision to follow God’s call to the priesthood or religious life can have the undesirable consequence of deeply disappointing non-devout parents who are set on grandkids. Going to Mass on Sunday can make you miss family gatherings, or sports events, that will end up in hurt feelings or missed opportunities for your kids.

That’s okay. We have to do these things anyway. Just like Daniel had to pray, despite the risks. And we worship a God who brings good out of evil. We worship a God who closes the lions’ mouths and turns the brokenness of the world to His own glory.

That doesn’t mean we can do evil or desire evil but bad things happen as a result of doing what we must do, we can trust in God to make all things ultimately work for the good.