Another well-put concept, written by David Markham himself.

As therapists know, psychiatry is not an exact science. In fact, it is mostly descriptive. The DSM IV, (Diagnostic and Statistical Manual, 4th edition) published by the American Psychiatric Association, describes various “mental illnesses” which are defined as a certain set of symptoms. Making a psychiatric diagnosis is kind of like astronomy, one gazes at the various symptoms as if at stars, and as various constellations emerge in some pattern, we give it a name.

He continues by describing the trend of state legislatures attempting to define mental illness, and links to an article in the Psychiatric Services Journal that provides in-depth consideration.