Fashions will change, but Paul Graham is accidentally creating the impression that fashion is purely random. It is not. The word "retard" as a reference for the mentally handicapped is not going to come back into fashion; it has been obsoleted by a better understanding of both the processes of mental and developmental disability and of the role of the mentally handicapped in society.
Which is all for the better, because the verb "retard" is useful, and it would be great if fashion made it less clumsy sounding in normal speech.
I'd say that is precisely what they don't do. That's magical thinking (what sort of energy is this "charge"?) and I think it's the core of what's wrong with political correctness: people imagine that they're fixing reality by doing surgery on language, but they're not; they're fixing a reflection of reality, with "fixing" in the sense of "price-fixing". In other words it's photoshopping.
That's why intent matters: it actually exists, while the intrinsic power of bad words does not. Ignore intent and you end up in an absurd place.
In extreme cases this leads to personal harm being caused, but those are pretty rare. What bugs me more is how rigid people get when they try to correct others. That special blend of prissiness and condemnation is an anti-peanut-butter-cup, and it just makes me want to say "jehovah" over and over again like the dude in http://www.youtube.com/watch?v=R_hlMK7tCks.
It also misses how language really works. Language changes as people change. We can't control it, and it's silly to pretend that we can. That's like King Canute who ordered the waves to stop (except Canute's whole point was that they wouldn't comply, even for a king).
The truth about all this is told by the great comedians who mine the contradictions between language and social norms. Is there one piece of great comedy defending the politically correct view of language? I'd love to see it.
p.s. Just to be clear, I don't mean that you try to censor other people—I've never noticed anything of the sort. It's clear that your interest in this topic is in wanting not to hurt others with words inadvertently. That's totally distinct from the language-police impulse and I admire it. But I disagree with your model, I think.
And words obviously have the power to frame issues. An inheritance tax is a sensible measure that increases government revenues at the point where money has its lowest marginal value to its owner, while also serving as a check on dynastic wealth. A death tax is an outrageous injustice by an overreaching government that surely seeks next to tax breathable air.
I think this seems dumb because you're intent on looking at attitude and language as a discrete causal relationship. But it's not; it's continuous and reciprocal. Some people condemn racism. The n-word is gradually shunned. The shunning of the word becomes another vector for the idea that racism should be condemned.
Surely, there are people who would like skip the "people change" step, and proceed directly to policing our consciousness through control of the language. But I'm always struck in articles like this one how silly the motivating examples are; a student with a complaint about the word "niggardly" in Chaucer? Come on, that's small-ball compared to institutional racism. Which, if you made it that far into this article, is the reason USDA had a (silly, I agree) $200k seminar with a speaker asking the audience to say "The Pilgrims Were The Original Illegal Aliens": USDA had, believe it or not, been an epicenter for modern institutional racism, recently forced to pay out almost $2bn in settlements to black farmers who had been denied aid.
Surely, you're not militating for the return of the word "retard". Are you sure we really disagree?
I'm not here to to argue that there's no such thing as "political correctness" --- though I dislike that term, which appears in modern usage to mostly be a tool for defending privilege. But all I chimed in here to say was that linguistic fashion isn't random.
Words condition our thoughts and feelings and behavior. So it's not just that people-change causes language-change; there's a feedback loop. But it's not a feedback loop we can control with anything as heavy-handed as ideology. To attempt to intervene that way is exceedingly crude. That's why it's associated with rigid thinking and pushy behavior.
In its milder forms that intervention is nannyism; in its more virulent forms it turns into persecution. Is it as evil as racism itself? The question seems ridiculous. If I have to answer, the answer is "obviously not", but really that whole line of thinking is a distraction. I don't accept that a repressive attitude towards language is of the least value in correcting injustice.
I could go on about this indefinitely so perhaps I'll stop here.
One day back in the 80s Blue Peter decided it was going to do something about discrimination against what were then known as "spastics" (I will use the term as it is historically correct). So they got someone on called Joey Deacon (see, I can still remember the name) to show that they were just normal people despite their physical condition.
It backfired spectacularly. The next day in the playground, "Joey" was the insult of choice. Now this may just be because kids are stupid and cruel but there is a lesson there: you can't do social engineering by clumsy attempts to manipulate language. It just doesn't work. So (for example) nowadays when we hear that a kid has ADHD, everyone just rolls their eyes and knows perfectly well that is just the PC way to say "bad parenting".
But my point is, PC doesn't really work. Everyone "knows" what is really meant by any of the PC terms.
As a counter example, I applaud the gay community for putting the brakes on the politically-correct-damning of the word "gay" which was on it's way to becoming an 'offensive' term. I suppose some still things it is, and of course some teenagers still use it with ill intent, but I think most agree that it's not 'bad' when used in a 'proper' manner.
Of course, there's another way - making the euphemism so clunky and unnatural that nobody outside of professional context would be willing to use it. Thus things like "differently abled".
I'd also strongly contest the 'nothing to do with better understanding', given that we now have multiple ways to classify mental issues, where previously they were all lumped into huge, overbroad groups.
Edit: I guess I should elaborate. Developmental delay is an indicator of a problem. It's not meant to be a final diagnosis - where possible, a reason for the delay is sought out. 'Developmental delay', like 'mentally retarded' is a symptom - it's just in olden days it was left there; the root cause was rarely sought.
Yes, the term can be misleading, and I don't like it for that reason. But it's not 'feel-good' nor incorrect in fact. It's an accurate description of what is happening.
Sure, people who knowingly inject offense into their speech and then cry 'free speech' are assholes. So too, though, are the people that cry foul at someone else innocently (if naively) expressing themselves.