Okay! I think I’ve found, at last, the key to all the differences between Catholicism and every denomination that goes by the name of Christian!

Those differences, have, for a long time, seemed to me like nothing more than an odd list: we’re not the only Christians who can boast of an ancient and glorious liturgy, and we’re not the only Christians to have the Mass – but we are the only Christians for whom skipping Mass on Sunday is a sin. We’re not the only Christians to venerate Our Lady or to believe in her Dormition – but we are, (I think) the only Christians who believe she was free from sin from the moment of her conception. We’re not the only Christians to believe in grace, but we are unlike most Protestant denominations (I can’t speak for the Orthodox here) in that we believe in a merit that is quantifiable and in some way measurable. And so on.

Over the weekend, I read a Russian Orthodox description of the Catholic idea of the Church, as “…a large and seaworthy vessel built by a famous master, (and) navigated by a skilful pilot,” and which, insofar as it or any Church is institutional, only subsists within a mystical Church, in which human divisions of doctrine and hierarchy are irrelevant. Suddenly, all the memories of all the conversations I’ve ever had with Protestant, Anglican and Orthodox Christians about strange aspects of Catholicism crashed upon my mind in a single wave of understanding, and I saw the difference between us and everyone else. Catholics value the res in a way that other people do not. And from that, everything else proceeds.

A res is a thing. It needn’t be corporeal and available to the senses, but, even where a res is immaterial, it is still, in its own way, discrete, bordered, individual. Catholics need as many things in their faith to be this kind of thing as possible. Non-Catholics do not. And that is pretty much it. The Catholic is like a child (in the best sense of the word), who points to something and says, “What’s that?” and expects a clear-cut answer, or he says, “Where is such-and-such” and expects the other person to point to a discrete object and answer, “There.” This is why, to the Catholic, the idea of an invisible mystical unity sundered from any signs of visible unity makes no sense. The Church founded by Jesus Christ is a res. Where is it? An institution is a res. Is that the same res spoken of by Our Lord? If not, where is that one? And so on.

A similar argument breaks out over the subject of grace. I remember an involved conversation with an Evangelical Protestant who said, “It sounds like you think of grace as something like money, that you can get more and more and more of.” In a certain sense, he was right. For us, a virtuous act is a res. That an act is virtuous does not mean simply that it is categorised a particular way. No, each act of virtue has its own distinct existence and value, like a brick or a coin, which continues to exist once the moment of action has passed. If I perform three acts of charity, I have three res to my credit in heaven. If I perform three hundred acts, my eternal life will be glittery with those three hundred res. This is not a universal Christian idea, and it would be interesting to look into its origins. It would also be interesting to discover how much of this habit is Catholic thought and how much of it is Western. I remember a conversation with a Maronite Catholic, in which he said of our definition of transubstantiation, “You Westerners – you’re full of words and definitions. We just adore the mystery.” He didn’t love the res as we did…but he would never have described Eastern Orthodoxy as the true faith.

Now, I’m not arguing here about whether or not we’re right to think this way. I’m only saying that we do think this way, and I’m proposing it as the reason why we’ll never agree with the people who don’t need everything to be a res. I have, in fact, no idea at all how you’d go about defending the Catholic love of the res as a starting point. Perhaps it is indefensible, and my insight is worthless. So, instead of declaring to my interlocutors that they disagree with me because they don’t know how to love the res properly, I shall have to content myself with the low blow, and tell them that they only love their doctrine because it means they get to sleep in on Sunday mornings and be disobedient and have multiple wives. And then they can tell me that I’m really a pagan and also stupid and I don’t know anything. And so on.