The principle of double effect

Updated Wednesday 27th February 2008

Is there a difference between deliberately killing someone and doing something that will lead to their death? Nigel Warburton explores the Doctrine of Double Effect.

Some people believe there is a significant moral difference between deliberately killing someone and performing an action that you know will result in another's death. These people subscribe to what is known as the Doctrine of Double Effect, a principle drawing a distinction between intentionally doing something undesirable and doing something where you foresee an undesirable consequence, but don’t wish this consequence. The name 'Double Effect' comes from the fact that the action in question is thought to have two effects: a good one (intended) and a bad one (merely foreseen).

It may sound esoteric, but this principle has many vitally important applications: for example in medical cases. A doctor may justify administering a lethal pain-killing drug that predictably hastens a patient's death on the grounds that she aims to lessen the patient's pain rather than kill him. 

Critics of this view, including strict utilitarians, will say that if the predictable consequences are the same, the moral worth of the actions must be the same. If you know your actions will result in a death, what difference can it make if you intend this death, rather than merely foresee it? Some of those who subscribe to the Doctrine of Double Effect do so because they are members of a religion that has an absolute prohibition on intentional killing; from outside these religions the double effect doctrine can look like a convenient kind of conscience-saving rationalization. 

Through a series of ingenious, if highly implausible, thought experiments involving out-of-control trolleys, innocent people tied to railway tracks (and, in one case, a fat man pushed over a bridge), Michael Otsuka defends the Doctrine. In this weeks’ Ethics Bites, he claims that our intuitions about these cases support the Doctrine. 

I'm not completely convinced he's right. Perhaps what we need to do is abandon our intuitions, rather than stick to the Doctrine.

Further Reading

 

For further information, take a look at our frequently asked questions which may give you the support you need.

Have a question?

Other content you may like

Niccolò Machiavelli (1469 - 1527) Copyrighted image Icon Copyright: BBC article icon

History & The Arts 

Niccolò Machiavelli (1469 - 1527)

Introducing the Florentine thinker and political theorist, Niccolò Macchiavelli:

Article
Buddhism's four Noble Truths Copyrighted image Icon Copyright: The BBC video icon

History & The Arts 

Buddhism's four Noble Truths

This animation explores the Buddha's Four Noble Truths.

Video
5 mins
Ethical Science Copyrighted image Icon Copyright: Used with permission article icon

History & The Arts 

Ethical Science

Can science be ethical as well as innovative? Should it even try? Barbara Brockbank considers the issues.

Article
Rewiring the Brain Copyrighted image Icon Copyright: BBC video icon

History & The Arts 

Rewiring the Brain

Has technology rewired our brains? Explore technology and humanity in this animation from A History of Ideas.

Video
5 mins
Trolleys, killing and the doctrine of double effect Copyrighted image Icon Copyright: photos.com audio icon

History & The Arts 

Trolleys, killing and the doctrine of double effect

Would you let someone die, to save five others? Would you kill someone to save five others? Explore trolleys, killing and the doctrine of double effect.

Audio
15 mins
What is 'evil'? Copyrighted image Icon Copyright: photos.com article icon

History & The Arts 

What is 'evil'?

Anita McNaught played Open Minds host to resident philosopher Jon Pike and special guest Richard Swinburne, Professor of Christian Philosophy at Oxford University to consider the subject of evil.

Article
What's wrong with killing? audio icon

History & The Arts 

What's wrong with killing?

Is it ok to wage war? Is it ok to defend yourself against an attacking army? Ethics Bites asks if it's always wrong to kill.

Audio
15 mins
Human use of animals Copyrighted image Icon Copyright: BBC audio icon

History & The Arts 

Human use of animals

Peter Singer, possibly the most famous philosopher in the world, sparked the birth of the animal rights movement. Discover his take on the human use of animals

Audio
15 mins
Habeas Corpus Copyrighted image Icon Copyright: The BBC video icon

History & The Arts 

Habeas Corpus

Should anyone be held imprisoned without charge? Stephen Fry explains how, despite Habeas Corpus, this can still happen. 

Video
5 mins