138 5 Court and the Legal System—Adult ForensicsThe Historical Basis of the Insanity Defense
The case of Daniel M'Naughten is generally regarded as the historical origin of the
insanity defense. M'Naughten shot and killed the British Prime Minister's secretary
in 1843. The jury found M'Naughten to be insane at the time he committed the
offense and acquitted him of the charges. The verdict in the M'Naughten case
was somewhat controversial at the time and consequently resulted in an official
process of inquiry wherein English common law judges were given the task to
determine the precise standards for competency. The first official test to determine
a defendants sanity developed out of these proceedings (Moran, 1981).
The test that came to be known as the M'Naughten Test required clear proof
that the individual was, at the time he or she committed the offense, under defect
of reason resulting from a disease of the mind and that such defect resulted in the
individual not being able to recognize the nature and quality of his or her actions (or
not knowing that such actions were wrong). The idea behind such a rule concerns
the presence of mens rea. It is often thought that insane persons do not possess
sufficient metis rea (criminal intent) to be found guilty for the crimes they commit.
As mens rea along with actus reus (wrongful act) are the necessary components for
criminal liability, the absence of necessary intention on the part of the actor justifies
not punishing the individual. The M'Naughten Test for insanity became the official
determinant of sanity in Great Britain and its standard was adopted by the United
States.
The M'Naughten Test eventually expanded to include an "irresistible impulse"
component. In such cases, an insanity defense was raised on the grounds that the
person knew the nature and quality of their actions, knew that it was wrong, but
whose mental disability resulted in an "overpowering compulsion" which did not
enable the individual to resist the actions he or she undertook. The rationale for the
"irresistible impulse" provision was that such a powerful compulsion was sufficiently
strong that the prospect of criminal punishment would not act as a deterrent and,
thus, persons should not be held accountable for their actions.
In 1954, Judge David Bazelon proposed an even broader test for insanity (Durham
v. United States, 1954). Judge Bazelon opined that "an accused is not criminally re-
sponsible if his unlawful act was the product of mental disease or mental defect''
(pp. 874—875). In reacting against the cognitive test of M'Naughten and in consid-
eration of the available psychological literature at the time, the Durham Test held
that ""fojur collective conscience does not allow punishment where it cannot im-
pose blame" (pp. 666—667). In other words, we punish those committing criminal
acts of their own free will and criminal intent (i.e., mens rea). Those persons whose
actions are the result of a mental disease are not held to be morally responsible for
their actions and, consequently, should not be punished as others.
Like the M'Naughten Test, the Durham Test also sustained its share of criticism.
As a result, the American Law Institute (ALI) proposed its own test for insanity.
This test would be known as the ALI Test. The ALf Test holds that "a person is not