> Common sense certainly does not.
If somebody has diminished mental capabilities then commonsense certainly does dictate that such a person has diminished responsibility.
That is why you must be compos mentis to sign a Will or to take out a bank loan or to drive a car.
> the term “mentally ill” is a popular brush that paints a very wide - and liberal - swath.
Have much to do with the mentally ill? Or is this just your opinion?
From my viewpoint, I sit on a Board of Trustees of an organization that provides care and services to mentally ill people. They require help in order to function: some more than others. We are not in the habit of providing care and services to healthy people, if for no other reason than we cannot afford to: hardly a “liberal” swath.
> - like doping your son with Ritalin because he is in some way “ill.”
If you are treating your son with Ritalin he will probably have been diagnosed with Attention Deficit Hyperactive Disorder or Chronic Fatigue Syndrome: both perfectly sensible uses for the drug... except, of course, for medical luddites.
> Medicine has no place in legal issues,
Arrant nonsense! Tell that to the cops next time they blood test you for drink-driving.
> or moral ones either, for that matter.
Sure it does. That is why hospitals have Ethics Committees.
> The law is simply a crystallized prejudice of the current social mores and changes all of the time.
Tell that to the judge just before he sentences you, see how sympathetic he is to your viewpoint.
A man that had this man’s elaborate and carefully planned escape (cash, passport, ticket, etc) is not mentally ill. Cerntainly not to the point of diminished capacity to discern right from wrong which would diminish his legal and moral culpability.
His actions were in fact those of a “guilty mind” who knew exactly what he was doing and exactly how wrong it was.