The Principle of Double Effect Part 1: What Is It?

The Principle of Double Effect has a long history and is a fascinating topic of discussion. Yet many people do not know or fully understand exactly what it is. What does it mean? How does it affect my life? Let us attempt to answer these questions and give a synopsis of the essence of this Principle.

The most basic of questions to start off with is: What is the Principle of Double Effect?

The Principle of Double Effect, or PDE for short, is a term used in philosophical and ethical discussions, especially, though not exclusively, those of a Catholic persuasion. PDE seeks to figure out when it is permissible for a person to do something if that action brings about both a good and a bad effect.

There are an infinite amount of real-life scenarios that tie in to this. Here are a couple of examples. One is if a doctor needs a patient’s blood to do some tests, but the needle used to get the blood will cause pain to the patient. Is it licit for the doctor to retrieve the patient’s blood despite the pain being caused by his actions? Most people would agree that the answer is yes, but the real question is why we would agree on that. PDE attempts to give a proper answer to that question.

Another, and hopefully less common, example would be if you were on a train that was heading straight for your mom who was tied to the tracks. You have control of a button, however, that you can press to switch the train onto another track, saving your mother. However, three people who you do not know are tied to the other track. Is it moral/acceptable to press the button?

This is a silly scenario that we will never have to experience, but such scenarios can help us to understand other more common and perhaps even more difficult situations. For instance, if someone was attacking you or a loved one, would it be acceptable for you to use force, even lethal force, in order to stop the attack?

In each of the above examples you have an action that will produce both a good effect and a bad effect. In the first one the doctor will get the blood that he needs to do proper health tests for the patient, yet it will also cause an undesired pain in the patient. In the second one, you pressing the button will result in your mom’s life being saved, but will also result in the death of the three strangers. In the third one, the good effect is that you are protecting the life of yourself or a loved one, yet the bad effect is that the attacker may be seriously injured or even dead.

It is these types of situations that the Principal of Double Effect attempts to resolve. And as you can see some of them are much more difficult to grapple with then the others. But if PDE is sufficient then it will be very helpful in these and other more day-to-day events in one’s life.

In short, PDE states that it can be acceptable for a person to choose to do something even if that action provides both a good and bad effect provided that certain criteria are met. Those criteria are:

1. The action itself is not bad or evil; it needs to be either morally good or morally neutral.
2. The person intends the good effect to happen but does not intend the bad effect to happen; he/she merely allows or has knowledge that the bad effect will happen.
3. The good effect cannot be achieved through the completion of the bad effect; in other words, the good effect must come about as a result of the action itself and not as a result of the bad effect.
4. The amount of good that is gained from the good effect must be able to compensate for the harm from the bad effect.

According to PDE all of these criteria must be met. If even one of them is not met then the action should not be done. If the action meets all four of these criteria, however, then it is permissible for the person to do the action.

In upcoming articles we will break down what each of these criteria mean as well as PDE’s practical applications to our lives.