Talking about talking: That's so meta(phor)!

I've been very remiss in writing about language lately! I mean, it's on my banner and everything! I've had a topic tucked away in my head for months now, and I'm finally getting it written down. Hope you find it interesting, and don't forget I'll answer any language questions you've got!

Historical linguists have noticed something striking about how the meanings of words change over time: abstract words (words denoting a concept that can't be detected by the senses) always develop from earlier concrete meanings, not the other way around.
 
Continued after the jump...