If you were like us, you noted that the Holy Father appeared to rely on St. Thomas Aquinas fairly heavily at crucial moments of Amoris laetitia. (And if you didn’t notice it, take our word for it.) We have been left wondering what the general quality of the Holy Father’s Thomism was, not being ourselves in a position to judge it. At the always-excellent blog, Laodicea, “Thomas Cordatus” walks through the Thomistic arguments in Amoris laetitia. He’s not uniformly impressed. A sample,

Paragraph 304 seeks to recruit St Thomas in favour of having no unvarying law about how to act towards those in e.g. adulterous situations. It quotes a passage from 1a 2a 94, 4: “Practical reason deals with contingent things, upon which human activity bears, and so although there is necessity in the general principles, the more we descend to matters of detail, the more frequently we encounter defects…  In matters of action, truth or practical rectitude is not the same for all, as to matters of detail, but only as to the general principles.” Presumably one is supposed to think that St Thomas would have said that therefore you can’t have a fixed principle of not giving Holy Communion to those who live in an adulterous relationship, but only a defeasible presumption of not doing so. The problem with this is that it ignores his, and the Church’s, teaching about intrinsically evil actions. Since some actions are intrinsically evil, one can indeed have unvarying negative precepts, saying that such and such a thing must never be done, whatever the circumstances. Affirmative precepts, on the other hand, such as giving back a loaned article when the lender requires it, bear on a good to be done and not on an evil to be avoided, and since goodness requires not only a good object but also the right circumstances, affirmative precepts can be suspended in particular cases (e.g. don’t return a gun to a madman.) The precept of not giving Holy Communion to those in public mortal sin is a negative precept, based on the intrinsic evil of dishonouring the Church.

(Emphasis supplied.) Read the whole thing there.

And while you’re there, you also need to read the comments. “Thomas Cordatus” points out in some detail a potential contradiction between Amoris laetitia, para. 301, and Trent’s eighteenth canon on justification, which itself refers to Romans 11. It’s a straightforward application of “you’ve got to dance with the one what brung you.” You cannot say that the commandments of God are impossible, even for one in a state of grace (can. 18); since Amoris laetitia teaching that those in irregular situations may be in a state of grace (AL ¶301), Trent says that you cannot say that the commandments of God, including, of course, perfect continence in their irregular situations, are impossible for them. But Amoris laetitia says, “[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 otherwise without further sin” (¶301 [emphasis supplied]). Now, at no point does Amoris laetitia say straight out that it’s impossible for the subject to obey God’s commandment, but it sure sounds like it says that.