We’ve seen that, precisely because it’s a serious duty, to refuse to pay the debt without a serious reason is a mortal sin against justice, and it’s also a mortal sin against charity.
|The primary purpose of marriage...|
So what is the Pope doing here? The Pope is explaining the rules, not making the rules. He’s explaining how God made things. In fact, everything we’re going to hear from the Holy Father can be reasoned out from what we already know about marriage, the marriage contract, and the purpose of marriage.
Pope Pius XII makes this clear:
Economic: this refers to true financial hardship. True financial hardship. In such a profoundly materialistic society as ours, this one requires brutal honesty before God. All too often in our culture, we see the trappings of life placed ahead of life itself.