Pope Francis has stated multiple times that Amoris Laetitia is rooted in the moral theology of Thomas Aquinas. The citations to Aquinas in Chapter eight have been commented on by others, but quotations from the works of Aquinas are not the only way in which Amoris Laetitia (AL) draws on the Angelic Doctor. More fundamental is the Thomistic foundation that is not directly alluded to in AL but which nevertheless grounds much of the controversial statements of chapter eight. That foundation consists of Aquinas’ answer to the question: “Can mortal sin become venial?”
Like many of his answers, his answer to the question “can mortal sin become venial?” is both yes and no. Logically, the only way for this to be possible is by making a distinction.
Aquinas makes a distinction between sins that are generically venial (or mortal) according to their object, and sins that are venial “from the cause”. What makes a sin venial “from the cause” is imperfection in the source of the action, “as when a sin contains something diminishing its guilt, e.g. a sin committed through weakness or ignorance: and this is called venial ‘from the cause’”(II-I Q.88 Article 2).
On the other hand, sins “can have a determinate genus, so that one sin may be venial generically, and another generically mortal, according as the genus or species of an act is determined by its object” (II-I Q.88 Article 2).
It is from this generic perspective that mortal sins cannot become venial sins.
“…a sin which is generically mortal, can become venial by reason of the imperfection of the act, because then it does not completely fulfill the conditions of a moral act, since it is not a deliberate, but a sudden act, as is evident from what we have said above (Article 2)” (II-I Q.88 Article 6).
Hence, “it may happen, on the part of the agent, that a sin generically mortal becomes venial, by reason of the act being imperfect, i.e. not deliberated by reason, which is the proper principle of an evil act” (II-I Q.88 Article 2).
So the answer to the question “can mortal sin become venial” is NO if we view sin generically, ‘by its object’. However, the answer is YES if we consider sin from the disposition of the agent, ‘by its cause’.
Now why is it that when the pope reminds us, like Aquinas before him, that mortal sin becomes venial in some messy situations, a great hand-wringing and hair pulling and gnashing of teeth goes on? “This is justifying objective sin”, the objection goes. “This is allowing exceptions to the objective moral law”, “this is a free pass for adultery”, “this destroys the very foundation of Catholic morality!” What explains this reaction?
Well, one thing that explains it is these two aspects of human action are being conflated. Because if you don’t recognize the category of the venial sin ‘by the cause’ and only recognize sins ‘by the object’, then of course every effort to posit a venial sin ‘by the cause’ is going to look like a denial of sin ‘by the object. Every attempt to draw attention to the fact that ‘adulterers’ may in fact be only sinning venially in some messy circumstances (and therefore possibly eligible for communion), is taken as a denial of adultery per se, or as a double standard, or situation ethics (the denial of objective sin). The practical consequence of not making this distinction is that all talk of mitigating circumstances will not compute. The message will just be interpreted as “No Objective sins” or more specifically, “Adultery is not a Mortal sin” or “adultery is not grave matter”.
But to say that the mortal sin of “adultery” may become venial in a particular act because of ignorance or weakness is not to say that there no longer exists adulterous kinds of acts, or that a free pass for adultery exists for some people, but only that some particular acts cannot be characterized morally as adultery because of the imperfection of the act at its source. Unlike some critics who think that the consequences of this is the destruction of all of Catholic morality, Aquinas says that under such circumstances it is the “species” that is destroyed (the species of adultery in this case). It’s not destroyed generically, somebody somewhere will still be guilty of committing adultery, but the species is destroyed in this particular action by this particular person under these particular circumstances at this particular time.
Why is such a basic distinction, present in law and catechisms, now suddenly mystifying and suspicious? Why is elementary moral theology now being side-eyed and dismissed as loopholes?
I believe it’s because some Catholics are uncomfortable with the existence of weakness. They don’t believe that the weak exist because they don’t believe that weakness is really a thing (the Neo-Pelagian mentality?). That’s why everything comes back to ignorance for them, “Oh just inform the sinner of his mistake and all will be well. If he continues sinning, that’s on him.” But weakness is independent of ignorance. Weakness is not a knowledge problem. Nor is it a repentance problem. The person who is weak may know the law, agree with the law, love the law, and yet still can’t obey it. That’s what weakness means.
Hence, “more is involved here than mere ignorance of the rule. A subject may know full well the rule, yet have great difficulty in understanding ‘its inherent values’, or be in a concrete situation which does not allow him or her to act differently and decide other-wise without further sin” (AL 301).
Nevertheless, people continue to characterize unfree, morally compromised, or coerced actions as if they were free, consensual, and perfect acts of moral agency. Making these category errors between freedom and weakness, between sins ‘by the object’ and sins ‘by the cause’, it’s no wonder they see chapter eight as a threat to the whole foundation of moral theology.
So Pope Francis is echoing Aquinas when he says “it is reductive simply to consider whether or not an individual’s actions correspond to a general law or rule, because that is not enough to discern and ensure full fidelity to God in the concrete life of a human being.” (AL 304)
Because “moral acts derive their character of goodness and malice, not only from their objects, but also from some disposition of the agent” (II-I Q.88 Article 2). A ‘disposition’ like weakness or ignorance. The attempt to measure human beings merely by holding their actions up to an objective rule is what the philosopher Rocco Buttiglione calls “ethical objectivism” – the opposite error of the subjectivism of situation ethics.
Amoris Laetitia doesn’t repudiate the objective view of morality, but it does ask us to stop neglecting the subjective disposition of the agent, especially when we are judging a person’s fidelity to God.