Catechism
An Explanation of the Baltimore Catechism of Christian Doctrine, Lesson 25, The opening
"Unction" means the anointing or rubbing with oil or ointment. "Extreme" means last. Therefore Extreme Unction means the last anointing. It is called the "last" because other unctions or anointings are received before it. We are anointed at Baptism on three parts of the body—on the breast, the back, and the head. We are anointed on the forehead at Confirmation; and when priests are ordained they are anointed on the hands. The last time we are anointed is just before death, and it is therefore very properly called the last anointing, or Extreme Unction. But if the person should not die after being anointed would it still be called Extreme Unction? Yes; because at the time it was given it was thought to be the last. It sometimes happens that persons receive Extreme Unction several times in their lives, because they could receive it every time they were in danger of death by sickness. Suppose a person should die immediately after being anointed in Baptism or Confirmation, would the anointing in Baptism or Confirmation then become Extreme Unction? No. Because Extreme Unction is in itself a separate and distinct Sacrament—a special anointing with prayers for the sick. Oil is used in Extreme Unction—as in Confirmation—as a sign of strength; for as the priest applies the holy oil in the Sacrament, the grace of the Sacrament is taking effect upon the soul. This Sacrament was instituted as much for the body as for the soul, as all the prayers said by the priest while administering it indicate. It is given generally after a person has made his confession and received the Viaticum, and when his soul is already in a state of grace; showing that it is in a special way intended for the body. It must be given only in sickness; for although one might be in danger of death if the danger did not come from within, but from without, he could not be anointed. A soldier in battle, persons being shipwrecked, firemen working at a great fire, etc., could not be anointed, although they are in very great danger of death; because the danger is not from within themselves, but from without. If, however, these persons were so frightened that there was danger of their dying from the fright, they could then be anointed.