The word phrase "mentally ill" is legally invalid. First, the word phrase "mentally ill" is not found in Webster's Dictionary and is not found in the Oxford Dictionary, and thus, is really not a traditionally recognized word. Blacks Law Dictionary defines "mental illness" as a psychological condition involving mood or cognitive thought which substantially impairs a person's judgment regarding reality. One problem with this definition is that the Diagnostic Statistical Manual used by psychiatrists and health insurance companies uses mental health diagnostic categories which deal primarily with beliefs, not with mood or cognition. Additionally, there is the problem that "impairment of judgment" in relation to "reality" requires some agreed upon or objective definition of reality. In point of fact there is no such agreement on the nature of reality. Some persons are idealists, some are naive realists, some are empiricists, some are critical thomists, some are critical realists, some are nominalists, and some are logical positivists. It appears that most psychiatrists are logical positivists of some sort. However, there are two problems with this. First, there are a number of different types of logical positivism, for example: experience logical positivists, sense experience logical positivsts, dictionary logical positivists, and authority logical positivists. The only valid position is to be an experience/sense experience logical positivist, but most psychiatrists, wrongly, do something else. Morever, the Existence of God can be proved with logic and or logical positivism, and so the naive=corrupt logical positivism used by many psychiatrists is really voodoo psychiatry. Finally, it should be noted that the word phrase "mentally ill" is invald because "mentall ill" has no concrete referent and is a reified concept.