Does the priest in Calvary recommend mortal sin?

Calvary is a very difficult film with some punishingly harsh content, as I’ve tried to emphasize whenever I’ve recommended it, and I’m not surprised to hear that you didn’t like it. In the scene you describe, Fr. James is speaking to an extremely disturbed young man named Milo who is having murderous thoughts and says he is getting “angry” toward women over his lack of sexual experience. He also says he has basically exhausted the possibilities of pornography, which he uses so heavily that he has worked his way up (or down) to transsexual porn (one of the film’s few revelations of evil leaving even the jaded priest at an actual loss). Fr. James tries to discourage Milo from joining the Army for the thrill of potentially murdering someone, but Milo is unreceptive of this advice, even arguing that the possibility of wanting to murder someone — and specifically being perceived by women as wanting to murder someone — could be a plus, compensating for his shortcomings.

The scene then cuts, and Fr. James and Milo are outside, so it’s implied that Fr. James has continued speaking with him for some time, presumably continuing his efforts to encourage him in a better direction. The term “better” is key here. It is a relative term, and in some cases what is “better” than the likely alternative may still be quite bad. I don’t see Fr. James as actually endorsing or condoning moving to the city and meeting looser women. He just wants to point out what would be a less damaging alternative to the paths Milo is contemplating. Fr. James has apparently concluded that Milo is sufficiently far from any path of actual virtue that the best he can reasonably hope for in the moment is to try to minimize the damage of Milo’s short-range choices.

This is an application of what Catholic moral theology calls the law of gradualism, i.e., the principle that moral conversion can often be a slow process in which people move by stages toward virtue. To invoke the law of gradualism always invites the counter-question: Is this really the law of gradualness, or what Pope John Paul II critically called the “gradualness of the law,” i.e., the false idea that there are “different degrees or forms of precept in God’s law for different individuals and situations”? Had Fr. James mentioned the possibility of moving to the city and meeting women with loose morals in confession and proceeded to give Milo absolution, I would say this was a clear case of bogus “gradualness of the law,” but there’s no sacrament here, or evidence that Milo is practicing in any way.

It is certainly true that Milo could go to hell following the path Fr. James mentions. It is equally true that Milo appears headed toward far deeper circles of hell, and that his choices may have dire consequences not only for himself but for others as well. And, critically, Milo has proven resistant to Fr. James’ attempts to discourage him from this course. If the best Fr. James can reasonably hope for at the moment (and even this might be a long shot) is to possibly deflect Milo to a less-bad but still mortally sinful path, then to try to do so seems to me both defensible and charitable.

I can understand why you found the scene off-putting. I see it as a case in point of what we see of Fr. James throughout much of the film: a very good priest — one of the most winsome ambassadors of faith that I have seen in any movie — trying to minister as best he can in a punishingly difficult pastoral situation.