October 4, 2022
unsoundness of mind

Origin of Law: Why does law Exempt lunatic person from Punishment?

The test of legal insanity under Section 84 IPC is whether the accused, at the time of the commission of the criminal act, was so afflicted by unsoundness of mind as to render him incapable of understanding the nature of his acts or that he is doing what is either wrong or contrary to law.

mental Illness as an exemption from punishment

The origins of the legal test to except unsoundness of mind from the rigours of the criminal law, had come up for discussion in the early case of R v. Edward Arnold [1724, 16 How St. Trials 765], where Justice Robert Tracy, in his summing up to the jury, is reported to have stated as under:

 “If a man be deprived of his reason, and consequently of his intention, he cannot be guilty; and if that be the case, though he had actually killed my lord Onslow, he is exempted from punishment: punishment is intended for example, and to deter other persons from wicked designs; but the punishment of a mad man, a person that hath no design, can have no example. This is on one side. On the other side, we must be very cautious; it is not every frantic and idle humour of a man, that will exempt him from justice, and the punishment of the law.

When a man is guilty of a great offence, it must be very plain and clear, before a man is allowed such an exemption; it must be a man that is totally deprived of his understanding and memory, and doth not know what he is doing, no more than an infant, than a brute, or a wild beast, such a one is never the object of punishment;

if you believe he was sensible, and had the use of his reason, and understood what he did, then he is not within the exemptions of the law, but is as subject to punishment as any other person. Gentlemen, I must leave it to you.

In the aforesaid passage, Justice Robert Tracy drew a clear distinction between “idiocy” and “lunacy”, which, translated in today’s terms, would mean “mental retardation” and “mental illness”, respectively.

Wild beast Test

The threshold alluded to by Robert Tracy, J. contemplated a person “totally deprived” of his senses at the time of commission of the criminal act so as to be akin to no more than a wild beast. The expression captured the imagination of lawyers and academics at that time and was popularly alluded to as the “Wild Beast Test”.

R v. Lord Ferrers[1] – Defence of Partial Insanity

In this case, a defence of “partial insanity” was set up by the accused. The prosecution argued that criminal liability cannot be avoided if the accused possessed so much reason so as to enable him to comprehend the nature of his action, and “discern the difference between good and evil” at the time of commission of the criminal act. The fact that Lord Ferrers committed the murder with coolness and deliberation weighed against him. He was found guilty and executed.

R v. Hadfield[2]

Hadfield had attempted the regicide of George III in a theatre in Drury Lane. Though he did not suffer from “total insanity”, in the sense explained by Tracy, J. in R v. Arnold (supra), yet, the importance of this case lies in the fact that the jury were successfully persuaded by Erskine (later, the Lord Chancellor Sir Thomas Erskine) to accept that delusions in cases of partial insanity can also form a basis for acquittal. Erskine is reported to have stated:

“Delusion, therefore, where there is no frenzy or raving madness, is the true character of insanity.”

The immediate outcome of this case was the enactment of the Criminal Lunatics Act, 1800, which prohibited an accused acquitted on the ground of insanity to go scot-free. The Act required the accused to be institutionalised and kept away from any further danger to society.

This Act is an early ancestor of the present day Section 335(1) Cr.P.C. (Person acquitted on the ground of unsoundness of mind to be detained in safe custody)

M’Naghten Case

In 1843, the infamous M’Naghten’s case (R. vs. M’Naghten, 1843 8 E.R.718) was decided on 20.01.1843. In this case, One Daniel M’Naghten opened fire with a 20 shilling pistol at Edward Drummond, the Secretary of the then U.K Prime Minister Sir Robert Peel, on a delusive belief that Drummond was the Prime Minister. Poor Drummond lost his life and M’Naghten faced trial for murder in which the Lord Chief Justice Tindal, in his charge to the jury, is reported to have addressed as under:

The question to be determined is, whether at the time the act in question was committed, the prisoner had or had not the use of his understanding, so as to know that he was doing a wrong or wicked act. If the jurors should be of opinion that the prisoner was not sensible, at the time he committed it, that he was violating the laws both of God and man, then he would be entitled to a verdict in his favour: but if, on the contrary, they were of opinion that when he committed the act he was in a sound state of mind, then their verdict must be against him.”

Read also-How a series “Victoria” depicts the background of “M’Naghten Rules”?

The jury found that M’Naghten suffered from morbid delusions which firmly pointed towards legal insanity. The jury eventually returned a verdict of “not guilty”, which was the subject matter of great debate in the House of Lords.

The House of Lords took the unprecedented step of summoning the learned judges of the Central Criminal Court to put to them five abstract questions of law.

The real purpose of such an exercise was to fully acquaint themselves of the legal position so as to consider whether any change by way of legislation was necessary.

The judges were then summoned, and the replies given by Tindal C.J to the five questions posed to them by the House of Lords have now assumed the acronym “the M’Naghten rules”.

First Act on lunatics in India

These events in England had their ripples in India by way of the enactment of Act IV of 1849 titled “The Act for the safe custody of criminal lunatics”.

This is the first piece of legislation which carved out unsoundness of mind as a statutory exception to a criminal offence. Act IV of 1849 was eventually repealed after the IPC had come into force (vide Act XVII of 1862) as the exception in the 1849 Act had been subsumed into the present Section 84 IPC.

Section 84 IPC substantially incorporates the M’Naghten’s rule and reads as under:

84. Act of a person of unsound mind. —Nothing is an offence which is done by a person who, at the time of doing it, by reason of unsoundness of mind, is incapable of knowing the nature of the act, or that he is doing what is either wrong or contrary to law.”

The test of legal insanity under Section 84 IPC is whether the accused, at the time of the commission of the criminal act, was so afflicted by unsoundness of mind as to render him incapable of understanding the nature of his acts or that he is doing what is either wrong or contrary to law.

Difference between “Mental retardation” and “Mental illness”

The expression “unsoundness of mind” occurring in Section 84 IPC is a compendious term, which includes both “mental retardation” and “mental illness” or in colloquial terms “idiocy” and “lunacy”.

Though a person may suffer from mental retardation, it is possible that he may still be able to lead a normal quality of life. The Supreme Court explains this in the following passage from   Eera vs. State (NCT of Delhi) and another [(2017) 15 SCC 133]:

“I have copiously referred to the said authority as it has analysed the distinction between “mental illness” and “mental retardation”. It has also noted that a condition of mental retardation or developmental delay is gauged on the basis of parameters such as intelligence quotient (IQ) and mental age (MA) which mostly relate to academic abilities. The Court has narrated about the possibility of late IQ or MA may possess the social and emotional capacities that will enable him or her to be a good parent. Persons with borderline, mild or moderate mental retardation are capable of living in normal social conditions even though they may need some supervision and assistance from time to time.”

Mental Healthcare act, 2017, which defines “Mental Illness” also distinguishes Mental illness and mental retardation. It reads as follows-

 “(s) “mental illness” means a substantial disorder of thinking, mood, perception, orientation or memory that grossly impairs judgment, behaviour, capacity to recognise reality or ability to meet the ordinary demands of life, mental conditions associated with the abuse of alcohol and drugs, but does not include mental retardation which is a condition of arrested or incomplete development of mind of a person, specially characterised by subnormality of intelligence

Mental Healthcare Act, 2017

The Indian Lunacy Act, 1912, was repealed by the Mental Health Act, 1987 which was also repealed and replaced by the Mental Healthcare Act, 2017. Chapter XIII of this Act sets out the responsibilities of other agencies like Courts and the police in dealing with mentally ill persons in general and mentally ill prisoners in particular.

Section 103 of the Mental Healthcare Act, 2017 empowers the Court, acting in exercise of powers under Section 335 Cr.P.C[3], to pass a reception order directing the admission of a prisoner with mental illness into any suitable mental health establishment.


Mental illness is a taboo in India. People can admit any disease to their family member but cannot accept that s/he is suffering from any mental illness. It is true that none would easily accept that s/he has some mental illness and requires treatment. People will normally go on a denial mode. In fact, in our country, there does exist, even now, a belief that marriage will cure mental illness, as if it is the panacea therefor, little realising that, post marriage, the life of the other spouse is going to be in jeopardy.

Due to this mentality towards mental illness, this disease become gross and patients suffers and even allowed to roam in public which result in crime by lunatic and idiot.

To curb these crimes, it is necessary to pay the attention on the treatment and care of lunatic people, which can turn them into a civilized people.


  1. Vijay Pratap Singh v. state (2021)

[1] (1760, 19 How St Tr, 885)

[2] [1800 27 How St Trials 1281]

[3]Section 335 – Person acquitted on such ground to be detained in safe custody: (1)Whenever the finding states that the accused person committed the act alleged, the Magistrate or Court before whom or which the trial has been held, shall, if such act would, but for the incapacity found, have constituted an offence,-

(a)order such person to be detained in safe custody in such place and manner as the Magistrate or Court thinks fit; or (b)order such person to be delivered to any relative or friend of such person.

(2)No order for the detention of the accused in a lunatic asylum shall be made under clause (a) of sub- section (1) otherwise than in accordance with such rules as the State Government may have made under the Indian Lunacy Act, 1912 (4 of 1912 ).