More amazing insights from CS Lewis, pages 98-99.
But what, it may be asked, is the use of keeping two people together if they are no longer in love? There are several sound, social reasons; to provide a home for their children, to protect the woman (who has probably sacrificed or damaged her own career by getting married) from being dropped whenever the man is tired of her. But there is also another reason of which I am very sure, though I find it a little hard to explain.
It is hard because so many people cannot be brought to realize that when B is better than C, A may be even better than B. They like thinking in terms of good and bad, not of good, better, and best, or bad, worse and worst. They want to know whether you think patriotism is a good thing: If you reply that it is, of course, far better than individual selfishness, but that it is inferior to universal charity and should always give way to universal charity when the two conflict, they think you are being evasive. [...] they go away complaining that you would not give them a straight answer. I hope no one will make this mistake about what I am now going to say. [...]
This is another thing I have often thought about. Imagine the leap from thinking in terms of good or bad to thinking in terms of good, better, or best. It’s incredible. What’s beyond that? More complex ways of thinking? More sophisticated reasoning? Ideas and truths that I can’t even yet imagine?