Acton University faculty member Jeffrey Tucker has an insightful essay over at InsideCatholic.com, “Why Catholics Don’t Understand Economics.”
Throughout the piece, Mr. Tucker employs a distinction between scarce, economic goods, and non-scarce, infinitely distributable, spiritual goods:
I have what I think is a new theory about why this situation persists. People who live and work primarily within the Catholic milieu are dealing mainly with goods of an infinite nature. These are goods like salvation, the intercession of saints, prayers of an infinitely replicable nature, texts, images, and songs that constitute non-scarce goods, the nature of which requires no rationing, allocation, and choices regarding their distribution.
None of these goods take up physical space. One can make infinite numbers of copies of them. They can be used without displacing other instances of the good. They do not depreciate with time. Their integrity remains intact no matter how many times they are used. Thus they require no economization. For that reason, there need to be no property norms concerning their use. They need not be priced. There is no problem associated with their rational allocation. They are what economists call “free goods.”
[…] This is completely different from the way things work in the realm of scarce goods. Let’s say that you like my shoes and want them. If you take them from me, I do not have them anymore. If I want them again, I have to take them back from you. There is a zero-sum rivalry between the goods. That means there must be some kind of system for deciding who can own them. It means absolutely nothing to declare that there should be something called socialism for my shoes so that the whole of society can somehow own them. It is factually impossible for this to happen, because shoes are a scarce good. This is why socialism is sheer fantasy, a meaningless dreamland as regards scarce goods
The whole article is worth reading (there is even a good St. Augustine reference)