Some months ago I was in a Twitter feud (actually several) with an individual who has been something of a representative of the best there is in the world of lefty moral thought which is trying very hard to convince people just how orthodox it is to think that sometimes it is just so difficult to avoid committing adultery (after a divorce and attempted remarriage) that it might not be seriously sinful. (I’ve left Twitter for various reasons, so don’t bother looking. This despite having been followed shortly before my departure by the former co-host of what was at that point, back in 2020, for some time the most popular podcast in the world. Alas.)

We’re not talking about a case of severe cognitive impairment like schizophrenia or some other dissociative disorder that would render one minimally responsible or completely innocent, or some kind of extreme scenario involving physical violence (which would then arguably reduce to the former through inducing overwhelming fear or pain). We’re talking, “But I really like this man/woman and it would be really hard to leave him/her and really hard not to commit adultery, and/or I’m really afraid what he/she would do/not do to the children/me if I withheld myself, and it’s just too difficult to procure an annulment for some reason and rectify the situation.” Not over fractions of a second. Over weeks, years, decades.

The argument basically goes that because there are elements in the situation which make virtue difficult, such as social pressure, conditioning, anxiety, and similar factors. Therefore, the person is not entirely free to make a moral choice. (The hinge text for this argument is the CCC’s paragraph on self-abuse – #2352.)

One must either thus consign all of human agency to the whims of circumstances out of one’s control, which is to succumb to a kind of determinism which renders the will some kind of illusion, or one must accept that in fact real deliberation (or its seriously blameworthy absence) of itself suffices to provide the kind of freedom necessary for serious guilt in materially grave sins.

The Catholic answer is the latter. St. Thomas explains this in the ST I-II q. 77 a. 8:

Mortal sin, as stated above (I-II:72:5), consists in turning away from our last end which is God, which aversion pertains to the deliberating reason, whose function it is also to direct towards the end. Therefore that which is contrary to the last end can happen not to be a mortal sin, only when the deliberating reason is unable to come to the rescue, which is the case in sudden movements. Now when anyone proceeds from passion to a sinful act, or to a deliberate consent, this does not happen suddenly: and so the deliberating reason can come to the rescue here, since it can drive the passion away, or at least prevent it from having its effect, as stated above: wherefore if it does not come to the rescue, there is a mortal sin; and it is thus, as we see, that many murders and adulteries are committed through passion.

There is a lot to talk about with respect to Thomas’ treatment of the reason vis-a-vis external action (i.e. passions’ ability to forestall reason, the relationship between deliberation and the eternal types of the moral law, his treatment of sudden murders), but here we can simply point out that he has noted that both the “sin itself” (sinful act) and the “wanting to sin” (a deliberate consent) with regard to grave matter (i.e. murder, adultery) are only able not to be grave sins if the deliberating reason cannot come to the rescue and prevent the passion from having its full effect (which would be the case with someone who is insane). The passion (fear, desire, a mix of both) inclines one towards a certain action (such as adultery), and the reason will either repel the action (virtue) or not (grave sin) – certainly, over days, months, years, a sane person’s deliberating reason is being brought to bear upon their external actions.

In short, if you are able to think meaningfully about an action – which a sane person can certainly do if given days or even years to do so – then you are meaningfully responsible for choosing it.

My interlocutor was finally cornered on this and just refused to accept it. I then left him to his own counsel. There’s no point in arguing about this.

Sometimes we cut down trees we should have left alone, and they become our crosses. And those crosses are sometimes very large – but it puts the bearer in a position to go from a very bad place to a very good place extremely quickly, with the heroic courage required of them. We need pastors who will accompany people in making that hard, quick, large jump from death to life. We don’t need soothsayers telling people that it’s not all that serious if it’s difficult.

No amount of books, conference papers, journal articles, footnotes, or other texts can change this. It is the truth about human agency, and such truth is not subject to textual amendment.