Morality is concerned with the knowingly chosen acts of human persons. There are three sources or ‘fonts’ of morality, which determine the morality of any act:
(1) intention,
(2) moral object,
(3) circumstances.
Every act with three good fonts is morally licit; it is not a sin. Every act with one or more bad fonts is morally illicit; it is a sin. Each font is evaluated as to its morality based on the two great commandments: to love God above all else, and to love your neighbor as yourself. An ordered love of God, neighbor, self is the basis for all morality.
Catechism of the Catholic Church: “The morality of human acts depends on: the object chosen; the end in view or the intention; the circumstances of the action. The object, the intention, and the circumstances make up the ‘sources,’ or constitutive elements, of the morality of human acts.” (CCC, n. 1750)
Compendium of the Catechism: “The morality of human acts depends on three sources: the object chosen, either a true or apparent good; the intention of the subject who acts, that is, the purpose for which the subject performs the act; and the circumstances of the act, which include its consequences.” (Compendium, n. 367)
USCCB Catechism: “Every moral act consists of three elements: the objective act (what we do), the subjective goal or intention (why we do the act), and the concrete situation or circumstances in which we perform the act…. All three aspects must be good — the objective act, the subjective intention, and the circumstances — in order to have a morally good act.” (USCCB Catechism for Adults, July 2006, p. 311-312)
1. The intention is of the subject, the human person who acts. You have control over your own intentions. If your intention is immoral, change your intention. Your intention is the purpose or goal for which the act was chosen. But for this font to be moral, all that you intend must be moral. It is not moral to intend to achieve a good end by an immoral means.
2. The moral object is of the act itself, the objective act chosen by the human person. Some acts are in themselves immoral; other acts are in themselves moral. The moral object is the end in terms of morality toward which the act itself, by its very nature, is directed. This inherent ordering of the act toward its moral object determines the essential moral nature (the inherent moral meaning) of the act itself. When the moral object is evil, the act is intrinsically evil and always immoral, regardless of intention or circumstances (the other fonts).
Pope John Paul II: “These are the acts which, in the Church’s moral tradition, have been termed ‘intrinsically evil’ (intrinsece malum): they are such always and per se, in other words, on account of their very [2] object, and quite apart from the ulterior [1] intentions of the one acting and the [3] circumstances. Consequently, without in the least denying the influence on morality exercised by circumstances and especially by intentions, the Church teaches that ‘there exist acts which per se and in themselves, independently of circumstances, are always seriously wrong by reason of their object’.” (Veritatis Splendor, n. 80; inner quote from Reconciliation et Penance, n. 17.)
You have no control over the objective moral nature of the various acts that you are able to choose. Evil acts remain evil, and good acts remain good, no matter what you may think or do. Nothing can transform an intrinsically evil act into a moral act. But you do have control over which acts you choose. If an act is intrinsically evil, your only moral choice is to choose a different type of act, one that is moral.
3. The circumstances follow from the intention and the act. A particular objective act is chosen for a particular subjective purpose, and the result is particular consequences; these are the three fonts. The circumstances are the good and bad consequences of the chosen act, in so far as these can be reasonably anticipated by the person at the time that the act is chosen. If an act can be reasonably anticipated to have bad consequences which morally outweigh any good consequences, then the choice of that act is a sin. If the reasonably anticipated good consequences morally outweigh any reasonably anticipated bad consequences, then the font of circumstances is good.
The three fonts of morality are the sole determinant of the morality of each and every knowingly chosen act, without any exception whatsoever. When all three fonts of morality are good, the act is moral — it is at least morally permissible. When any one or more fonts are bad, the act is immoral — it is a sin to choose such an act.
In moral theology, an act is the knowing choice of a human person. There are no morally-neutral acts. Every knowingly chosen act is either good or evil, either morally licit (at least permissible without sin) or morally illicit (a venial or mortal sin).
“no human act is morally indifferent to one’s conscience or before God” (Congregation for Catholic Education)
“Freedom makes man a moral subject. When he acts deliberately, man is, so to speak, the father of his acts. Human acts, that is, acts that are freely chosen in consequence of a judgment of conscience, can be morally evaluated. They are either good or evil.” (CCC, n. 1749)
For much more on ethics and the three fonts, see my book: The Catechism of Catholic Ethics.