EWTN Catholic Q&A
Question from DAO on 04-08-2014:

I'm having a Will written and the subject of Do Not resuscitate has caused a stir in the family. When is a person considered dead according to Catholic belief?

Answer by Judie Brown on 04-11-2014:

Dear DAO

Here is the Catholic definition of death: death occurs when the soul leaves the body at which point the body is a cadaver. At that point there are no bodily functions.

If you instruct caregivers not to provide the proper mechanical help for you in your time of distress, and the circumstances are such that providing it could save your life, then in a sense you are asking for someone else to kill you.

Since you cannot predict how you will die and of what you will die, such instructions can work against your wishes. My advice is to sign an American Life League LOVING WILL. See http://www.all.org/article/index/id/MjQ5NA

Judie Brown