In American English, things get a little trickier when you want discuss the common and unrelated matter of stupidity. Psychologists ruined several serviceable words for foolishness by categorising people with intellectual impairments (including categories of people to be forcibly sterilised) as dull, moron, idiot, even stupid itself*. The FWD (feminists with disabilities) blog did a number of Ableist Word Profiles which discussed some of this language.
In British English, foolishness or stupidity is all about behaviour and to my educated by not infallible knowledge, stupid people have always done stupid things, regardless of their IQ. When it came to not looking after people with intellectual impairment, we used imbecile a fair amount, but otherwise stuck to pleasant euphemisms such as feebled-minded, half-witted, backward and as one friend was cast in his youth, educationally subnormal. Special needs, basically.
There is, however, a problem with the language of mental health and the language of - I struggle to come up with a neutral term for the thing - outlandish irrational behaviour? For now, let's pencil in craziness. I feel this shouldn't be any problem for me - I have plenty of experience of mental ill health, I studied psychology and am acutely aware of the way diagnostic labels take on a cultural meaning which may have little bearing on what it's like to live with any given condition. As a disability activist, I'm also aware that people with mental illness are among the most vulnerable disabled people, not least because they're often left outside discussions of disability. I feel I should be able to talk about the world without any fear of using problematic language, but I'm not sure I can.
Yet this other thing is something we do have to describe. It's usually in the negative, although my choise of craziness is frequently used to describe positive exuberance or else a kind of higgledy-pigglediness; crazy in love, football-crazy, crazy paving, crazy quilting, crazy golf, crazy discounts in our mid-winter sale, “Oh we're never going to survive unless we go a little crazy”, etc.. People describe themselves as crazy when they mean quirky, fun-loving, impulsive and a bit annoying (well, maybe they don't mean annoying, but people who describe themselves as crazy often are). There are companies with crazy in the title, which just isn't the case for most slurs around mental illness – you could have a shop called the Crazy Pet Store, but the Psycho Pet Store? Not so much. Although I'd totally shop for a hamster there!
Usually when we reach for words to describe craziness, we're wanting to describe something which is not only bad but baffling in its wrongness, an extreme behaviour which defies all logic, common sense and decency. As well as a strong cultural tendency to explain heinous crimes in terms of mental illness, to tidy away messy and monstrous behaviour with neat labels and expert speculation, we reach for words which condemn in tone as well as vaguely-pathological definition; psychopath, psycho, sociopath, unhinged, deranged, maniac, mental etc.. Words which reference mental illness but get mixed in with evil, monster, freak. When we mix up the words, we mix up the ideas and leave people with mental ill health extremely vulnerable to fear and hate.
The opposite of craziness is also something we need to describe. When I talk about my experience of Post Traumatic Stress Disorder, I have to phrase it in terms of the jolt I received when I became sane. This sanity does not equate to mental health – clearly not, given that it co-incided with a psychological disorder – but only after I escaped and began to value myself, did the full horror of my violent marriage catch up with me. Even while I felt very sorry for my ex, my brain began to respond to thoughts of him, let alone contact with him, with abject terror, flashbacks and panic attacks. And although those things were disproportionate – I was perfectly safe by then, after all – it is completely sane to be terrified of someone who has frequently assaulted you and felt justified in their actions.
Although legally, sanity and insanity have specific definitions which refer to one's state of mind, none of these relate directly to mental health. For example, most people with even severe mental illnesses can vote, sign legal documents, and indeed, be held culpable for any criminal acts they commit – even if they have had their freedom taken away for safety reasons (psychiatric patients can be denied all these rights and responsibilities, but it's not a default thing). It's very rare indeed that people with chronic mental ill health slip over to being insane. Insanity is about losing touch of the fundamentals, particularly right and wrong.
There are lots of criminal acts which suggest insanity but, like the vast majority of crimes, are committed by people who have no diagnosable mental health condition. So for example, there's a very great deal of debate about the sanity of the Norwegian mass-murderer whose name I refuse to remember. The question of whether he was sane when he murdered seventy-seven people seems separate from the question of whether he had a mental illness.
Yet as I see it – and I'd really love to be corrected on this – the common usage of our language doesn't truly differentiate. Crazy is still a word which has great significance for many people with mental ill health, who have been dismissed, feared and attacked as crazy. As well as the impulsive fun-loving “crazy”, some people with mental illness identify themselves as crazy, as others identify themselves as mad. Sanity is still talked about very much in relation to mental health.
So where are the words we can use which don't muddle the medical with the non-medical?
(By the way, I don't mean to suggest that disabled people only have to worry about disability-related slurs. I don't think any of us think of a fool meaning someone with intellectual impairments, but recently this word was shaved onto the back of an unsuspecting man's head. I strongly dislike the word stupid because for years it was used to berate me for my poor co-ordination and cognitive dysfunction. Stupidity is a thing, but I do hate to hear anybody called it. Disabled people are called plenty of nasty names which have nothing to do with us.)
* Happily, the pain-stakingly categorical language of the mostly American psychologists and eugenicists did lead to Aldous Huxley coming up with classes of supposedly inferior people such as the “Epsilon Minus Semi-Moron” in Brave New World, which does roll off the tongue rather nicely when dealing with unco-operative broadband providers. Not really – as I recall, the Epsilon Minus Semi-Morons were very good at their jobs! No, really, of course, I don't call people names. Much.