Whazzat?
I don't believe I had ever seen the word before I read it in an article today in reference to the recent Dutch elections. It's a psychological term, coined by Freud as a translation of the German Libidobesetzung, meaning "the concentration of mental energy on one particular person, idea, or object." In the context at hand, the author argued, a small group of media and political trend-setters had decided that one candidate had clearly won a multi-party debate, and so ran with the story, giving the as-yet-undecided public something to latch on to. This in turn led to that candidate gaining ground in the polls, and so forth.
Cathexis, then, is a nice, short, pseudo-classical word for what we also call the bandwagon effect or perhaps groupthink, or at least that's how the author used it in this context.
After looking the word up, I thought, "Wow, what a nice, short, pseudo-classical word for something we see all the time. Maybe I should start using it."
And then my mind flashed an image of a salon somewhere, some concentration of intellectuals feeding off each other to produce a more-than-the-sum-of-the-parts ferment of ideas. And one hallmark of such a situation, as with any tight-knit circle, is that people will tend to come to use the same expressions and shorthands, the same obscure references and little-known (or completely invented) terms that just seemed to hit the spot. In extreme cases, this can tend to obscure, or even supplant, the actual ferment of ideas. Are they developing great thoughts together, or just throwing around the same terms of art?
Terms like cathexis.
So if I were to start using "cathexis" as though it were something anyone might be expected to know, and my vast army of readers did likewise (OK, I made up the part about the vast army), would I be fomenting cathexis myself? Does it matter if I actually have something to say?
Dunno.
Other words I looked up to make sure I was using them properly: salon (in the sense I used it), foment.
One bit of the dictionary definition I left off was "(esp. to an unhealthy degree)". It's not clear to me whether the author of the article had that shade of meaning in mind, or not.
