Posted by Neal on June 30, 2007
The boys and I were watching a 3-D movie about dinosaurs on the giant screen at the local science museum today, when all of a sudden I got that kind of uncomfortable feeling, a sense that something wasn’t quite right. What was it? Part of a popcorn kernel stuck in my teeth? Were my 3-D glasses sliding down? No, I realized, it was something the narrator had said. He had been telling how the best fossils formed when animals (or plants) were quickly buried, so that their remains would be
…undiscovered by predators or damaged by erosion.
So the best fossils are undiscovered by predators; that makes sense. Or they are … damaged by erosion? I had been under the impression that erosion generally didn’t make for good fossils, except for its role in exposing them to be found in the first place. But this movie was saying it did, and even implying that the best kind of fossils of all would be those (i) from animals whose remains had been found by predators AND (ii) which had been damaged by erosion.
Fortunately, I happen to know a bit about fossils, and was soon able to figure out that they had really meant that the best fossils were formed when the remains were NEITHER discovered by predators NOR damaged by erosion. In other words, they had meant to say,
…not discovered by predators or damaged by erosion.
…undiscovered by predators and undamaged by erosion.
So un- and not have almost the same meaning, but not A or B can mean ~A & ~B, but un- A or B can’t. Not can associate with an entire phrase, but un- associates with just a word. Put differently, not is used for syntactic negation; un- for morphological negation.
So what’s going on with the attempt to use un- for syntactic negation, the way they did in the movie? Unlike double passives or “Friends in Low Places” coordinations, I think this one is a mistake. I think someone editing the script read not discovered and figured it sounded better as undiscovered, without checking the larger phrase that was intended to be negated.