"The origins of the latest epithet in vogue are harmless." The origin of the word is irrelevant. Words mean things and can be harmful, regardless of the origin of the word. The meaning and context of words can change over time, regardless of the origin of the word.

Bringing Charles Darwin into the conversation does not help your point.

"Is it worse to have some condition of your birth used as a casual insult -- a reminder of your misfortune? Or is it worse to be constantly patronized, often behind your back by throngs offended on your behalf?"

This is a false trade-off. The whole conversation started because someone used a harmful word, knowing full well it was harmful. If they refrained from using the offensive word they knew was offensive neither condition would have happened (casual insult or patronization).

You know the euphemism treadmill right? The words moron and imbecile were once valid terms for mentally disabled, and offensive to use casually, but are no longer offensive in that way.

Conversely, people tried to introduce the term "special needs" to avoid the connotations of "retarded", and then "special" became an insult.

The word "lame" is also incredibly widely used and no longer considered offensive even though it's still a valid term for those who have difficulty walking.

I don't have a point, just find the whole thing very interesting. "retarded" is definitely in the grey area where I personally try to avoid using it, but it's still commonly used. Perhaps "crazy" and "insane" are next.

I was not familiar with the term "euphemism treadmill." Thanks for the info, that phrase does help bring some clarity and specificity to the discussion.

Is "fat" harmful? Could we say a company overspending is fat or bloated without offending? What about "impotent" or "bald," are they harmful? Can we use them abstractly without offending? What about "anemic?"

Lots of conditions of being are generally disfavored as a condition of our biology. Referencing that disfavor abstractly doesn't bring it in to being. Ignoring it doesn't make it go away.

These are all hypotheticals. Is there any serious, non-academic question about whether the word we're actually discussing is harmful? Even if there is, we all have a choice about what language we use and whether to respect the fact that certain words may hurt others. The cost of NOT using the relevant word is ... zero. This isn't an academic exercise. It's an emotional exercise.

I disagree. There's an ableist, patronizing assumption to be analyzed here: People with mental disabilities must have the language used around them carefully policed because they can't handle the implied disfavor and emotional harm that language may communicate via their own agency, not like the rest of us.

Sure, we shouldn't use harmful language and emotional intelligence matters. If you're overweight and talking with someone and they constantly find ways to derogatorily refer to your weight or even being overweight abstractly, they may be a jerk. But if someone online abstractly calls something fat, it's not directed at you. That's part of emotional intelligence in my opinion.

I do see your point and your explanation does add some nuance to my thinking on this topic. That being said, I still think it was a poor choice of words as evidenced by the fact that the majority of the replies are debating the OPs language as opposed to their original point.