In Catholic
fundamental theology, there are two methods of sanctification, known primarily by their
Latin terminology:
ex opere operato (from the work already done) and
ex opere operantis (from the work being done).
Ex opere operato
The phrase signifies that the dispositions of the individuals involved are not crucial to a certain action. This applies specifically to all the
sacraments. No
state of mind of the infant (nor of the
priest) is necessary for a proper
baptism. A
confession heard by a sinful
priest still brings with it a valid
absolution. Provided that lawful matter is used, an
ordained priest validly converts bread and wine into the
Most Holy Body and Blood of Christ, even if he carries the burden of
mortal sin.
Et cetera.
The significance of
ex opere operato is that the
sacraments are designated as having objective power. A cardiosurgeon with a bad heart can still perform a successful operation, and good advice from a bad person is still good advice. The faithful, in effect, are protected from the individual failings of clergy (and their own failing) when receiving the gifts
Christ directly instituted for them.
Ex opere operantis
This phrase signifies that the method of performing a certain action is fundamentally involved in the outcome of that action. This refers to
prayers,
sacramentals,
penances, faithful observations, and the like. If you say the
Rosary while thinking about what to eat for dinner, not much will come of it. Similarly, if you abstain from meat on
Lenten Fridays so your parents don't scold at you, or so others see you as observant, you will not receive the same
graces as someone who does it for love of
God and Church.
While actions
ex opere operantis lack power when performed with a weak heart, the converse works to our benefit. Actions performed incompletely or weakly through no fault of the individual still retain great power! A
mute person who cannot recite the
Rosary still receives great benefit from making the attempt to mouth the words, or meditate on them, or do what he can. A wealthy individual who makes a
pilgrimage to
Rome primarily for secular reasons is not receiving as much grace and blessing as the person of few means who makes a great sacrifice to make a local pilgrimage.
"When he looked up he saw some wealthy pople putting their offerings into the treasury and he noticed a poor widow putting in two small coins. He said, 'I tell you truly, this poor widow put in more than all the rest; for those others have all made offerings from their surplus wealth, but she, from her poverty, has offered her whole livelihood." (
Luke 21:1-4).