Before a person performs an action, they must have something in mind--the objective--which they intend to perform. The purpose of acting is to realise the objective. When we perform an act, we set out to achieve what our will wanted us to do. Now this might sound like stating the obvious and in one way it is, the problem is that when we try to achieve our objective we may cause other effects to come into being incidental to the realisation of our immediate objective.
Example: A man is involved in a motor vehicle accident. He has been flung out of his car onto the road in the path of oncoming traffic. He has also broken quite a few bones in his body. We happen upon the accident scene and try to move the man out of the path of oncoming traffic. Now in moving the man we cause him suffering and distress as every movement jostles his broken bones.
Now our objective is to move the man out of the path of danger, however in trying to perform this act we manage to move him out of danger while at the same time causing him considerable amount of pain. In actuating our objective we have also actuated this man’s pain. Now if we are aware that the man has broken bones we clearly foresee that the action of moving the man is going to cause him pain. How do you evaluate the determine the morality of an act when clearly both good and evil is happening at the same time as a result of a specific action?
Now our capacity to actuate our objective is limited to our means and circumstances. A elderly man may want to help our injured motorist but not have the strength to do it. A young lady may drag our motorist across the road, causing more pain than if he was gently lifted by paramedics yet both people have tried to actuate a morally good objective with various degrees of evil resulting as a result of their circumstantial limitations.
The prevalent view amongst a group of quite a few Christians--who should know better--is that the act is evaluated on the consequences, if one of the consequences is a foreseen grave evil then the act’s nature must be intrinsically evil and hence prohibited. The act is judged by its effects. By their reasoning, if a man performs an action in which he foresees his own death he must have intended suicide. If a pilot of a plane bombs a building in which terrorists have used hostages as shields he must have intended to kill the hostages. It is the doctrine of immaculate actuation.
They will of course deny that this is their reasoning and this is because they cannot see their error. All of them can state the principles of double effect and list examples of how they support it; up to a certain point. Once a certain psychological threshold is crossed, double effect is negated. While it is never OK to deliberately actuate pain or maiming to an individual as in torture they will quite happily accept it as a side effect of medical treatment. However once the unintended evil effects of an otherwise morally permissible action include injury to children or death to innocents then the principle of double effect usually is switched off: Double effect is applicable up to a certain threshold of unintended evil after which it is not on.
Now this is basically a repudiation of Veritatis Splendor. The document states that the morality of an act is determined by a moral analysis of the actors corporeal objective, not the effects of the realisation of the objective. The question to be asked is what was the actor trying to achieve by the action which resulted in both good and evil effects? The fact that a good action may have a bad effect does not automatically disqualify the action. St Thomas will back me up on that one.
Veritatis Splendor did not deal with the doctrine of double effect explicitly but its principles are easily applicable to the doctrine. In order for an action to be licit under the principle of double effect:
The actor must have a good moral objective and
A proportional analysis of the effects of actualisation of the action must on balance be good in order for the action to be permitted: The doctrine of double effect is the doctrine of conditional proportionalism.
The doctrine of double effect does not permit an actions which have a morally good objective but which on balance has bad consequences. Likewise double effect does not justify a morally bad objective if the consequences are good. Double effect also implicitly demands that we chose actions which minimise the bad consequences where that choice is available.