Insanity
-
What does 'insanity' mean in a legal context?
In criminal law, "insanity" refers to a mental disorder or defect that can relieve a person of criminal responsibility. Legal tests for insanity are not scientific definitions but serve to identify individuals whose incapacity warrants exemption from criminal responsibility based on social expediency and justice.
The M'Naghten rule, a key principle in Anglo-American systems, dictates that to establish an insanity defense, it must be proven that the accused had a "defect of reason, from disease of the mind" at the time of the act, such that they did not understand the nature and quality of their actions or that they were wrong.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
Why is the insanity defense used in court?
The insanity defense in court is used to relieve individuals of criminal responsibility due to a mental disorder or defect. It is rooted in the idea that to be held responsible, a person must have the capacity to understand moral distinctions and adjust their behavior to the law. The M'Naghten rule, a key principle in Anglo-American systems, states that a person is not responsible if they didn't know the nature of their actions or that they were wrong.
However, the insanity defense has faced criticism and varying legal tests. Some U.S. states allow juries to find defendants "guilty but mentally ill," where they may receive treatment while still serving their sentence. The core idea is that those with insanity should not be condemned if they lack moral culpability and cannot be deterred by punishment.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How do courts decide if someone is legally insane?
Courts determine legal insanity based on varying tests, not scientific definitions, to identify those whose incapacity warrants exemption from criminal responsibility.
The M’Naghten rule, used in Anglo-American systems, deems a defendant insane if, due to a mental defect, they didn't know the nature/quality of their act or that it was wrong. Some U.S. courts also consider "irresistible impulse." Critics argue these rules oversimplify mental disorders and don't align with modern science, complicating psychiatric testimony.
The American Law Institute's Model Penal Code test, once widely adopted, offers a defense if the accused lacked substantial capacity to appreciate their conduct's criminality or conform to the law. After the Hinckley case, Congress shifted back to a M’Naghten-like rule, with some states introducing "guilty but mentally ill" verdicts.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What happens to a person found not guilty by reason of insanity?
When a person is found not guilty by reason of insanity, it means that due to a mental disorder or defect, they are relieved of criminal responsibility. This is based on the idea that they lacked the capacity to understand the criminality of their actions or conform their behavior to the law.
Following a public outcry after the 1981 Hinkley verdict, which found John Hinkley, Jr. not guilty by reason of insanity in the attempted assassination of President Ronald Reagan, there was a significant change in American law. Congress and many states reacted by abolishing or greatly restricting the insanity defense, with some states passing laws allowing juries to find defendants "guilty but mentally ill." In these cases, the defendant may undergo treatment, but the sentence is still carried out.
1 Britannica SourceCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
How does the insanity defense differ from other legal defenses?
The insanity defense, unlike self-defense or necessity, hinges on the defendant's mental state at the time of the offense. It argues that the defendant lacked the capacity to understand the nature of their actions or that they were wrong due to a mental disorder or defect.
Different legal tests exist for insanity, such as the M’Naghten rule, which focuses on whether the accused knew the nature and quality of the act or that it was wrong. The American Law Institute’s Model Penal Code considers whether the accused lacked substantial capacity to appreciate the criminality of their conduct or conform to the law. Some jurisdictions also allow for a verdict of "guilty but mentally ill," where the defendant receives treatment while serving their sentence.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles. -
What are some criticisms or controversies about the insanity defense in law?
The insanity defense, excusing individuals from criminal responsibility due to mental disorder or defect, faces several criticisms. Legal tests for insanity, like the M’Naghten rule, are considered by some to be overly intellectualized and based on outdated concepts, complicating psychiatric expert testimony.
Following the Hinckley verdict in 1981, which applied the American Law Institute’s Model Penal Code, there was public outcry, and Congress moved to reinstate a test closer to the M’Naghten rule. Some states now allow juries to find defendants "guilty but mentally ill," where treatment is given, but the sentence is still carried out. There is also controversy around legal definitions of mental disorder not aligning with modern medical science.
2 Britannica SourcesCreated from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.
Insanity, in criminal law, condition of mental disorder or mental defect that relieves persons of criminal responsibility for their conduct. Tests of insanity used in law are not intended to be scientific definitions of mental disorder; rather, they are expected to identify persons whose incapacity is of such character and extent that criminal responsibility should be denied on grounds of social expediency and justice.
Various legal tests of insanity have been put forward, none of which has escaped criticism. Anglo-American systems, including that of India, base the law of criminal responsibility primarily on the famous case of Daniel M’Naghten. In M’Naghten’s Case (1843) the English judges held that “to establish a defence on the ground of insanity, it must be clearly proved that, at the time of the committing of the act, the party accused as labouring under such a defect of reason, from disease of the mind, as not to know the nature and quality of the act he was doing; or, if he did know it, that he did not know he was doing what was wrong.” Some U.S. courts went further and also relieved from responsibility one moved by an “irresistible impulse.”
These rules have been the object of sharp controversy. Critics charge that they express an overintellectualized concept of mental disorder, reflecting outmoded notions of human behaviour. The rules have been criticized as not being based on modern concepts of medical science, thus complicating the work of the psychiatrist in giving expert testimony.
" height="20" alt="HEW Logo">
Several U.S. states, and at one time most of the federal courts, adopted a test proposed by the American Law Institute’s Model Penal Code. This test provides a defense to a criminal charge if, at the time of the act, the accused, by reason of mental disorder or defect, lacked “substantial capacity either to appreciate the criminality of his conduct or to conform his conduct to the requirements of law.” In focusing on the volitional as well as the cognitive aspects of incapacity, this test has much in common with the European codes. The Italian penal code, for example, relieves a person of responsibility when that person “is deprived of the capacity of understanding or volition.”
The direction of American law of insanity changed significantly in 1981, following an attempt by John W. Hinkley, Jr., to assassinate U.S. Pres. Ronald Reagan. A federal jury found Hinkley not guilty by reason of insanity, applying the Model Penal Code formulation. In 1984, reacting to the public outcry following the Hinkley verdict, Congress repudiated this approach and by statute restored a test for insanity closer to the M’Naghten rule. Similar reactions occurred in many states, leading to abolition or greater restrictions on the insanity defense. Some states passed laws that allowed juries to find defendants “guilty but mentally ill.” In such cases, the defendant may undergo treatment, but the sentence is still carried out.
The major differences between the civil law of insanity and the common-law variant are procedural. The Continental codes ordinarily do not make use of lay juries in establishing responsibility, whereas the English-speaking jurisdictions do. Some countries, including Japan and England, identify a form of mental disorder short of insanity that may be taken into account in mitigating punishment.
Insanity is justified as an exemption from responsibility on the grounds that responsibility assumes capacity to make elementary moral distinctions and power to adjust behaviour to the commands of the law. The insane should not be condemned, since they are not morally culpable and cannot be deterred by the threat of penal sanctions. Critics say that the issue of responsibility is less important than the problem of how to identify and treat the disturbed individual. See also diminished responsibility.
The trusted destination for professionals, college students, and lifelong learners.
SUBSCRIBE
