Deconstructing the Criminal Defence of Insanity

The significance of this article is in its deconstruction of the criminal insanity defence in a meta-legal critical context. The article’s objective is to critically review beliefs that the insanity defence was designed solely for public protection from insane violent people, or, for criminal deterrence. Arising from the long and continued use of the Roman Law concept of non compos mentis, the question arises as to what has become of the practical meaning of the term “insanity”, when used as a defence. The article tries to show that the defence of insanity is a public act of judicial denunciation against the accused, while the accused may have no effective responsibility for the crime. Argument begins with a critical discussion on the character of common-place denunciation as an appeal to public agreement. Then, it follows how the idea of “manifest criminality”, of the 1800s, might be cognate to modern ideas of “manifest madness”, linking into the origins of the English special verdict of insanity. This will allow a short critical analysis of the M’Naghten Case. Argument is completed with analysis of a psychologists’ expert construct of insanity and its relationship to jury perception. The article will suggest strongly that arguments based on the common law rules of insanity tend to expose juries more to denunciation of the accused, than to a reasoned account of the nature of his insanity and to the defects in his responsibility. Duly persuaded jurors would tend to acquiesce and participate in the denunciation of an accused person, whose unusual and unhealthy behaviours emanated from his sufferings by dint of his unbearable circumstances.