Philosophical Perspectives on the Insanity Defense

1 The insanity defense and philosophy More has been written on the insanity defense than on any other single topic in criminal law,1 and yet statistically the plea of insanity is fairly rare, being considerably less common as a courtroom phenomenon than most laymen might expect.2 A reason for this apparent antinomy is that the insanity defense raises assumptions and issues that are at the very heart, the central philosophical core of the criminal law3 and, in the view of some, challenges the conceptual basis on which the criminal law rests. At the present time the criminal law is coming under increasing fire from theorists in the social sciences and social technology, who argue that it is based on an outmoded, unscientific and irreparable conceptual scheme, that of 'autonomous man', man as a free agent. These theorists would have us get on with the business of scientifically shaping behavior rather than bothering to pursue unfathomable inquiries into 'the guilty mind'. 4 Recent changes in legislation and precedents in the courts reflect a growing awareness and concern about the underlying philosophical conceptions that pose such a stumbling-block to clear and productive thinking on pressing issues related to the insanity defense, such as involuntary commitment, criminal responsibility, mental illness, psychiatric testimony and the role of experts in the law, the concept of the dangerous offender, and the McNaghten and Durham Rules in the courts. The kind of philosophical work so badly needed in these areas is clear-headed enucleation and extraction of the essential philosophical principles, and their statement in terms understandable to those who are concerned with criminal responsibility in the social sciences and psychiatry, and with law and legislation. This is a difficult but sorely needed undertaking, and I believe that philosophers should expend greater efforts on it. I hope that this paper will be the right sort of stimulus in encouraging a greater degree of productive rapport between philosophers and others who share a concern with the problems raised by the insanity defense.