Who should define Mental Illness?

Mental Illness is a term that is widely used to classify people who stray from what is normal. In the article, "Inside The battle to Define Mental Illness," Al Frances says that mental illness is, "virtually impossible to define precisely with bright lines at the boundaries." So we ask ourselves, Who should be the ones to define this interesting term? Frances argues in the article that the APA, or American Psychological Association, has the right to define this term but if there work proves to be "disastrous," he feels that it will lead to a change in who can define mental illness. It makes sense for the APA to define this term because it seems that this organization will have the most knowledge on the subject, but maybe others feel they have more of right to define this controversial term.