Clarification/Follow-up by tonyrey on 11/16/06 11:13 pm:
Jack,

There are other forms of insanity besides psychosis, e.g. imbecility and dementia.

Clarification/Follow-up by jackreade on 11/16/06 11:43 pm:
The word insanity is used in the law, the only acceptable use of the word these days.

It is not acceptable is to say someone is insane in medicine or describing someone in conversation. One says psychotic, or has Alzheimer's, or the name of a specific disease, like microcephalic or whatever. (I live in America, that may be relevant)

Materialism is called Metaphysical Naturalism.

And so on.

Clarification/Follow-up by tonyrey on 11/17/06 10:01 am:
Sanity and insanity are both necessary terms that are widely used:

"One can be acting under profound mental illness and yet be sane, and one can also be ruled insane without an underlying mental illness."

"In his classic book, The Sane Society, published in 1955, psychologist Erich Fromm proposed that, not just individuals, but entire societies "may be lacking in sanity". Fromm argued that one of the most deceptive features of social life involves "consensual validation":

"It is naively assumed that the fact that the majority of people share certain ideas or feelings proves the validity of these ideas and feelings. Nothing is further from the truth... Just as there is a 'folie a deux' there is a 'folie a millions.' The fact that millions of people share the same vices does not make these vices virtues, the fact that they share so many errors does not make the errors to be truths, and the fact that millions of people share the same form of mental pathology does not make these people sane." (Fromm, The Sane Society, Routledge, 1955, pp.14-15) (wikipedia)

Clarification/Follow-up by jackreade on 11/17/06 8:05 pm:
You are wrong.

What was acceptable in 1955 is not acceptable today.