Words To Use Today: non compos mentis.

 Non compos mentis means mad. Most people know that.

For non-Latinists the non and the mentis bits are guessable: that is, non means not and mentis will be something to do with mental.

The compos, as a child, I tended to associate with compost, but as it turns out there's very little connection between the two.

Mental illness is baffling, and often sad, and we have never really known how to deal with it. The mentally ill have been viewed in various times and places as divinely inspired; devil-led; worthless; seers; stupid; dangerous; feeble; to be shunned; to be locked away; to be a source of entertainment; to be ignored; to be treated; to be understood.

Sometimes it's not even easy to know which is those is kindest, let alone best.

Still, non compos mentis...this take on the idea of mental illness, which arose in 1200s England, seems rather a good one, considering.

Words To Use Today: non compos mentis. In Latin this means not in control of one's own mind. Com means with, and potis means powerful or master, and mens means mind.

Originally, in law, non compos mentis described those who had become incapable. In this case guardians were appointed to manage their affairs until they recovered. Those born disabled were called natural fools, and their interests passed to the Crown. 

The other legal category of mentally disabled people was habitual drunkards, who received no legal help at all.