Some years ago, I had a discussion with my son, Doug, about the kind of seating one might want in the front seat of a car. He said he preferred bucket seats because they help maintain stability. I’m sure he meant positional stability. I go slightly out of my way to specify that because I suspect we will be talking about other kinds before I finish up this morning.
I didn’t have any particular preference. I may never have thought about it before. I do think a fair amount about words, though, and something moved me to say that I preferred bench-style seats  because they help maintain lability.  I said that because I had the sudden intuition about the way the words were related to each other. The more stability, the less lability. The more lability, the stability.
And right after that, I realized that words are very seldom used like that. One of them becomes the idealized notion; the good end of the spectrum. And then deviations from it keep that notion. So we would say “instability,” as if “stable” were a good thing and therefore, “unstable” was a bad thing.
But that is true only if you keep the original image. What I did in my reply to Doug was to introduce another image, therefore another idealized notion, therefore another spectrum with another “good end.” So if “lability”—the tendency to slip easily along the bench seat—is a good thing, then you can keep that same image and prepare to complain about the loss of lability. There isn’t actually an English word for that from this family of words which makes this flight of fancy particularly valuable. I suggest illability, by analogy with illegality. [I think I begin to see something in Doug’s preference for bucket seats.]
The availability of such a word would have allowed me to complain about the pernicious illability of bucket seats using the same word model that Doug had used to complain about the instability of bench seats.
That was a long time ago; somewhere on the order of 30 years. And I still don’t care anything about bucket or bench seats, but the relationship of the words as anchoring different spectrums caught my interest at the time and interests me still. This is, after all, a relationship of relative values. I say “relative values” because absent context, there is no reason to prefer the one to the other. If you were stringing beads on a string to make a necklace and you found one that just wouldn’t go where you wanted it to go, would you really call it “stable.” Of course not. If the presupposition of the task is that slipping beads along the string is the goal, you will want a way or relating words (and therefore values) to each other that presumes the goal. So the good beads have “lability.”
So what Doug and I were really doing was presupposing some good state of affairs (slipping around, not slipping around) and naming the scale, the whole scale, according to that preference. Doug’s scale would go from stable to unstable. Mine would have gone from labile to illabile (had there been such a word at the time). Doug would have said that what I was calling “illabile” was actually just “unstable.” In doing that, he would move the word from my spectrum of meaning to his. I would have said—did say, actually, although I didn’t notice at the time—that what he was calling “stable” was just illability, moving the word from his spectrum to mine.
Had this gone on, he would, in time, have accused me of importing euphemisms, as if “labile” were just a good-sounding word for “unstable.” Had he done so, I would have accused him, in turn, of importing dysphemisms, as if “unstable” were just a good-sounding word for “labile.”
There is some sense in that argument, but the difference between a good-sounding word and a bad-sounding word is a small difference compared to the difference between the spectrums they represent. Doug chose a stability-emphasizing spectrum and what is a good word and what a bad word are controlled by that choice. I chose—pretended to choose, actually—a lability-emphasizing spectrum and what is a good word and a bad word are controlled by that choice.
Everything OK so far?
This substitution of one value dimension for another is the commonest thing in the world. There is a good reason for that. In many areas of discourse, the choice of value dimension which is crucial, tends to be invisible, whereas the choice of words, which reside on that dimension, are prominent.
I have heard Paul Simon’s excursion into African music—or African settings, at least, featuring African vocalists and styles—excoriated as “cultural appropriation.” Had he not gone that way, he could have been accused of “a music of racial purity,” or, more simply, of “racism.” You would have to know a lot more than I do about cultures and music to determine what, if any, merit there might be to those charges. My point is simply that “appropriation”  defines the category. In this context, it means “stealing.” Any word you want to use that falls along the spectrum defined by “appropriation” will bear the marks the the spectrum. People who think Simon’s venture into African music was more like a tribute to another musical tradition have not only substituted one judgment for another, but one spectrum for another. “Tribute” anchors another spectrum entirely.
This could go a lot further, as you can probably see, but let me bring it to a close by referring to a common clash of spectrums in contemporary politics. Then-President Trump made his demand of Vice President Pence on the grounds that Pence should be a “stand-up guy.” He was asking Pence to subvert the election process, to violate his oath of office, and to deny the certification of the votes of the citizens of the U. S.
You could start a spectrum at the “treasonous” end and then back slowly away. How treasonous was it? Not THAT treasonous. Trump began with another spectrum entirely, a “personal loyalty” spectrum. A “stand up guy” will do whatever he is asked to do at whatever cost to himself because of his loyalty to the cause, if there is a cause, or to the leader. As a matter of values, “treasonous” assesses the relationship between the formal demands of allegiance to the Constitution, while “stand-up guy” assesses the relationship between the dutiful follower and the leader. There is no point, in other words, in arguing (except in the context of a trial court) whether Pence was being urged to commit treason or to be a stand-up guy. Those are not terms that fall on the same spectrum at all. It is the choice of the spectrum that determines the value.
Pence’s choice, it turns out, was between moral lability and moral stability. Once the spectrum is chosen, which words are “good words” will not even be debated.
 If that is the right term, I am pretty sure he provided it later. It doesn’t seem very likely that I would have had it handy and I’ve told this story a lot of times since then.
 We get the word from the Latin verb labi, meaning “to slip;” not always in a physical sense. The adjective form, labilis, means “prone to lapse,” which doesn’t sound like a physical term. We do have “collapse” for that.
 As is often the case, the origin of the word gives a clue to the path it has traveled to make itself available to us. This one comes from the Latin verb propriare, meaning “to take as one’s own.” It was originally a financial term, but you can see how attractive it is as a token of cultural warfare.