Milton Mayer used to make fun of people who use Latin where they could just as well have used English. He managed to do that inoffensively by making that error repeatedly and then making fun of himself for doing it. I thought I would mention it because I am about to do it myself.
“Finem respice” he would say, “Principiis obsta.” Mayer died in 1984 but I can feel his gaze on my keyboard as I write this. “Envision the end” the saying goes, “resist the beginnings.”
I am working now with a marvelous book that Kendy Hess, my philosopher niece, brought to my attention and this morning, it occurred to me that the mechanism that C. S. Lewis uses in The Great Divorce is identical. What I am calling “the mechanism” is the trick of looking at the present from a hypothetical future time when all the events of our “present” have already occurred and we know what worked and what didn’t. Of all the claims we dealt with in our own time, we now know, from this hypothetical future, which were true and which misleading. This essay is about the advantages of knowing how everything is going to turn out.
A Broken World
Kendy passed along to me Tim Mulgan’s Ethics for a Broken World: Imagining Philosophy After Catastrophe. Mulgan has a person from our time—he calls it “the age of affluence”—visit the time from which he is writing. Since Mulgan is a savvy writer, he doesn’t say exactly when “the future” is, but he does locate it generally by saying that the age of affluence ended “only a handful of generations ago.” Let’s just artificially specify a handful as six and a generation as twenty years. So, for the purposes of this essay, he is writing from about 2140 C.E. 
As a way of making an argument, foreseeing the future with certainty—finem respice, remember—is a great advantage. Consider this passage from Chapter 1:
Our affluent visitor might initially refuse to believe that our plight represents the future of his affluent world. Drawing on the affluent faith in technology, he might be sure that human ingenuity must always outweigh the negative impact of climatic variation and uncertainty. We can only reply that, while this might have happened in a different possible world, it did not actually happen.
In our time—the affluent age—we still have a robust “faith in technology.” Smart people argue that this or that can be done. Mulgan has the advantage of saying “while this might have happened…it did not actually happen.” Mulgan knows what happened—“is happening,” we would say—and so he knows that the faith in technology was misplaced. And here we have John Kenneth Galbraith, whose book, The Affluent Society focused attention on the early phases of a lot of the issues that are completely out of hand by 2140.
When you actually know what happened, you gain a real clarity about what is—from our present perspective—still going on.
We might say of a friend that although he hoped that his speculative financial losses would be offset by his gains, that did not happen. He went completely broke by the time he was 37. We might say that it looked for a while as if a marriage doomed both participants to frustration and despair, but in fact, they came out of that bad time and lived happily together for another fifty years. Writers have an enormous advantage in knowing what actually happened especially when they are giving advice. We can “resist the beginnings” (principiis obsta) if we know the beginnings (finem respice).
Heaven and Hell
C. S. Lewis’s setting is entirely different, but the mechanism is the same. The “divorce” of the title is the separation between Hell and Heaven. Every day, the people in Hell (the Ghosts) have the chance to get on a bus and go to Heaven to commune with the people there (the Spirits), and to stay forever if they want to. Nearly everyone doesn’t want to. They get back on the bus in the afternoon and go back to Hell where, apparently, they feel more “at home.”
But while they are in Heaven, they are met by a Spirit who knew they in what we call “life.” In heaven, everything is known so the denials and evasions used by the Ghosts are transparently false, just as the “faith in technology” in Mulgan’s book is transparently false. Here are some examples.
The character I call “the Episcopal Ghost” is defending himself against the Spirit who has come to help him.
“Dick,” says the Ghost, “This is unworthy of you. What are you suggesting?
“Friend,” the Spirit answers, “I am not suggesting at all. You see, I know now.”
An artist wants to stay in Heaven so he can paint it. The Spirit who came to meet him, a fellow artist during their life, tries to explain what was really going on back on earth.
“When you painted on earth—at least in your earlier days—it was because you caught glimpses of Heaven in the earthly landscape. … But here you are having the thing itself. It is from here that the messages came. There is no good telling us about this country, for we see it already. In act we see it better than you do.”
A third Ghost is one I call the Rightsmonger. All he wants is what is his due
“I’m a decent man and if I had my rights, I’d have been here (Heaven) long ago and you can tell them I said so.”
“It isn’t true, you know,” says his friend, the Spirit.
“What isn’t true?” asked the Ghost sulkily.
“You weren’t a decent man and you didn’t do your best. We none of us did. Lord bless you, it doesn’t matter [any more].
So from a narrative standpoint, there is a great deal to be said for knowing all of the truth. In Mulgan’s work, you hear a lot of arguments that are being made today and that sound very plausible today. But when you know that they didn’t work—and in 2140, we do know that–the plausibility blows away like dandelion seeds. In Lewis’s fantasy, all kinds of self-justifications which any of us might use here in the present of our lives and/or might discount when we heard them used here, simply melt into incredibility before our eyes.
So, if you are thinking of writing a fantasy, I recommend that you or a narrative creature of your devising know what has happened. It makes everything else easier.
 I have recently read a book that is called 2312, by Kim Stanley Robinson, because that is the year in which the narrative takes place. In that book, our time is called “the age of muddling.”