The Magisterium teaches that the morality of each and every human act, that is to say, every knowingly chosen act of a human person, is determined solely and entirely by three fonts of morality:
2) moral object
If one or more fonts is bad, the act is immoral; it is a sin. Only acts with three good fonts are morally permissible. There are no morally neutral acts.
There is much discussion among the faithful and particularly among moral theologians on the moral object. If the moral object is evil, the act is intrinsically evil and always immoral. But the font of circumstances often receives too little attention in discussions of moral theology.
The morality of each font depends on a different end:
1) intention — the intended end; the goal or purpose of the act
2) object — the end toward which the knowingly chosen act is ordered, by its very nature
3) circumstances — the reasonably anticipated good and bad consequences of the act
In each font, if the end is bad, the font is bad. And when one or more fonts are bad, the act is immoral; it is objectively a sin.
The human will chooses an intended end and a concrete act (with a moral nature determined by its object). But the will also chooses to act with the knowledge that actions have consequences. So each font proceeds from the will to certain ends.
The circumstances of the act, past and present, inform the person has to what the consequences of the act might be. The reasonably anticipated good and bad consequences, along with their gravity and their likelihood, are evaluated to see if the act does more harm than good. If so, the circumstances are bad and the act would be a sin to choose. It is always a sin to act when you reasonably anticipate that your act will do more harm than good.
This idea, that a prudent evaluation of the circumstances of an act can make the act immoral, is a doctrine of the Church. The three fonts of morality are taught by the Magisterium in Veritatis Splendor as well as in the Catechism of the Catholic Church and other sources. It is not a mere theological opinion.
Applying this teaching on circumstances and morality requires a judgment of the prudential order. When an act is intrinsically evil, due to an evil moral object, the act is wrong by its type; that kind of behavior is always wrong to choose. Determining the type of the act (its genus or species or nature) will tell you if it is intrinsically evil or not. But determining if an act is wrong due to the circumstances requires an evaluation of many factors along with their moral weight.
This moral weight is affected by the likelihood of the good or bad consequences. The less likely an outcome is, the less moral weight it has. The morality of this font is also affected by the degree of harm in the bad consequences, and the degree of benefit in the good consequences, to all persons affected by the act. The totality of the foreseeable consequences of that act for all persons concerned.
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