A question raised just now at work: if something can be preemptive, why can’t it just be emptive?
It’s a somewhat obscure example of a linguistic phenomenon that pops up periodically. Somewhat more famously, perhaps, is the question of why we can be “overwhelmed” and “underwhelmed” but are never just “whelmed.”
What happens is a word loses its meaning. In Old or Middle English, you have a word like “to whelm,” which means “overcome, as with emotions or perceptual stimuli.” That word gets a modifier, like “over.” Then, over the centuries, people gradually start using the compound form more and stop using the original root, until today, “whelm” is basically meaningless without a modifier.
The same thing happened with preemption. Originally, “emption” was a real word, in the late 15th Century, a noun meaning “buying.” Emption meant you were buying something; preemption, about a century later, meant you were buying something before someone else. Over the years, it got generalized to mean to do anything before somebody else – chiefly some sort of blow or strike. Meanwhile, “emption” fell out of the language.
So if a preemptive attack is to attack before someone else, an emptive attack would be just an attack, without reference to relative chronology. In other words, it’d be a pretty meaningless term. In this case, then, there’s a good word why we don’t use “emption” in the modern sense of “preemption.”
This phenomenon is called a “bound morpheme,” a morpheme (or linguistic element) that doesn’t stand on its own, but only while bound to another morpheme. Thanks to Jon Stutte for digging this up!
Can you think of more good examples?
Another example is disgruntled/gruntled. We no longer say someone is “gruntled,” from “gruntle” which originally meant “to grumble” or to “grunt.” ”Dis” is an intensifier. So someone who is disgruntled grumbles a lot. But only the compound form survived. (Via Larry Kurtz)
Couth/uncouth. Our word “uncouth,” meaning “lacking good manners or refinement,” derives from the Old English uncuð _and originally meant “unknown,” from _cuð_, the past participle of _cunnan, “to know.” In the 16th Century or so it got its modern meaning. To the degree we say “couth” any more, it’s a back-formation from “uncouth.” (Via Pinedale Roundup.)
This post has been updated with the term “bound morpheme” and one or more examples.