lunacy or unsound mind, mental abnormality



It is referred to as lunacy or unsound mind, mental abnormality, disease of mind etc. an insane person cannot think and act as a normal human being. His capacity to know things is perverted. It is called ‘non compose mentis.' (possessed of a sound mind.)

If insanity is to be regarded as immunity first of all it must be clearly explained as to what it is. There being no standard of insanity, it becomes difficult to define insanity leading to the absence of mens rea.

Research methodology:

The researcher has adopted the doctrinal form of research in completing this project. As the project is primarily a case study on insanity, the doctrinal form of research was most appropriate. Primary as well as secondary sources of information have been used from the NALSAR Law Library. The above category of material consists of law reporters such as A.I.R., S.C.C., Cr. I.L. and commentaries on the Indian penal code written by eminent authors. Also, secondary soft copy sources of information have been perused from online databases such as Manupatra, J-Stor, lexis-nexis, hein, India Code and Judis. No part of this project is plagiarized and it is the original work of the researcher.

Developments Of Law

Wild Beast Test:

The first test for insanity evolved in 1724, called the test of wild beast in the Arnold case.The judge declared that no mentally affected mn prisoner should escape unless it should appear that he is totally deprived of his understanding and memory and shows not know what he is doing, no more than an infant, a brute or a wild beast.

Good And Evil Test:

This test evolved in 1800 and was applied to the case of R v. Madfield. The test laid down the “ability to distinguish between good and evil”. In the following case the accused was charged for high treason in attempting to kill the king. The defence pleaded that he was not able to distinguish between good and evil and ‘wild beast test' was unreasonable. He was acquitted.

Mc'Naghten Rule:

In 1843 the law of insanity was more properly formulated by the house of lords in the historic case of R v. Mc'Naghten.

Principles Laid Down In Mc'naghten Case:

  1. Every person is presumed to be sane, until the contrary is established.

  2. To establish the defence of insanity, it must be clearly proved that at the time of committing the crime, the person was so insane as not to know the nature and quality of the act he was doing or if he did know it, he did not know that what he was doing was wrong.

  3. The test of wrongfulness f the act is in the power to distinguish between right and wrong, not in the abstract or in general, but in regard to the particular act committed.

The English law on insanity is based on the Mc'Naghten rules and the Indian Law that is codified in the Indian Penal Code, 1860 s. 84, is also based on the Mc'Naghten rules. These principles have been incorporated in the penal codes of almost all the countries in the world.

Insanity Under Ipc And Cr Pc.

Insanity Under Indian Penal Code:

The defence of insanity is discussed in sec 84 of the Indian penal code which reads:

“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 doing the act, or that he is doing what is either wrong or contrary in law.”

Principles For The Application Of This Section:

The following principles are to be kept in mind in applying this section:

  1. every type of insanity is not legal insanity; the cognitive faculty must be destroyed as to render one incapable of knowing the nature of his act or that what he is doing is wrong or contrary to law;

  2. the court shall presume the absence of such insanity;

  3. the burden of proof of legal insanity is on the accused, though it is not as heavy as the prosecution;

  4. the court must consider whether the accused suffered from legal insanity at the time when the offence was committed;

  5. in reaching such a conclusion, the circumstances which preceded, attended or followed the crime are relevant consideration; and

  6. The prosecution in discharging its burden of the plea of legal insanity has merely to prove the basic fact and rely upon the normal presumption of the law that everyone knows the law and the natural consequences of his act.

Essential Ingredients Of The Section

Unsoundness Of Mind:

The term unsoundness of mind has not been defined in the code. But it has been equated by the courts to mean insanity. This section only deals with incapacity of mind which is a result of ‘unsoundness of mind' or ‘insanity'. It is not every type of insanity which is recognized medically that is given the protection of this section. Medical insanity is different from legal insanity. The insanity should be of such a nature that it destroys the cognitive faculty of the mind, to such an extent that he is incapable of knowing the nature of his act or what he is doing is wrong or contrary to law.This section will apply even in cases of fits of insanity and lucid intervals. But it must be proved in such cases that at the time of commission of the offence, the accused was surfing from a fit of insanity which rendered him incapable of knowing the nature of his act.

Legal And Medical Insanity Distinguished:

It is in the case of every person pronounced to be insane according to medical science to be excused? No insanity for the purpose of criminal law differs from that in the medical sense. According to medical experts, every case of mental abnormality is insanity. According to law not all persons who are medically insane are legally insane because amongst those who are medically insane some are able to control some times and behave like normal people. He as a normal man plans the crime; they sometimes can plan better and even execute it even with more care. He knows what he is doing is wrong. We judge a man's responsibility with regards to his mens rea. Only those cases where because of insanity he does not know what he is doing or he does not know what he is doing is a wrong, only they can be excused. So amongst all the medically insane persons, only a few are legally insane. The law propounds a different test from that in the medical field. The test in law is simply, whether because of his insanity he is incapable of possessing mens rea. It is only where the insanity destroys the cognitive faculty of mind, it is considered as insanity in law. The faculty of reasoning and judgement is also considered. An insane person is not punished because he does not have any guilty mind to commit the crime.

Kinds Of Insanity:

There are no hard and fast rules in respect of what are the kinds of insanity which are recognized by courts as ‘legal insanity'. A survey of the case law reveals that the courts are influenced more by the facts of the case and the nature of crime, rather than any formal evidence as to the kind of insanity that the accused is suffering from.

Law group's insanity into two broad heads, namely,

  1. dementia naturalis i.e. individuals that are insane from birth; and

  2. dementia adventitia or accidentialis i.e. an individual who becomes insane after birth.

Hallucination Or Delusion:

Hallucination or delusion is a state of mind where a person may be perfectly sane in respect of everything, but may be under a delusion in respect of one particular idea. The Bombay and the madras high courts have held that for a person who is not insane but is suffering from hallucination, this section cannot be invoked.


Somnambulism is the unconscious state known as sleep walking and if proved, will constitute unsoundness of mind and the accused will get the benefit under this section.

Irresistible Impulse, Mental Agitation, Annoyance And Fury:

Irresistible impulse, mental agitation, annoyance and fury all merely indicate loss of control and not indicative of soundness of mind. Every minor mental aberration is not insanity and the circumstances indicating a mere probability of legal insanity cannot however be sufficient to discharge the onus of the accused to establish the plea of insanity. Here the victim actually becomes a tool in the hands of the disease. This is called cognitive insanity

Insanity As Result Of Smoking Ganja Or Heavy Intoxication:

Where insanity is caused by excessive drinking even involuntary or by smoking ganja or other drugs, such insanity will also amount to unsoundness of mind, if it makes a person incapable of understanding what he is doing or that he is doing is something wrong or illegal. The accused can take shelter under this section, if he can prove that the insanity existed at the time of the commission of the act.

Lack Of Motive Or A Trifle Matter:

The absence of a strong and adequate motive to commit such a serious offence like murder is not by itself a proof of insanity. But the absence of a motive may be taken into consideration along with other circumstances of a case to determine the question of sanity or otherwise of the accused.

The fact that the accused caused the death of a person over a trifling matter will not by itself warrant a conclusion that he was insane, when no plea of insanity was taken before the trial court, nor was nay material produced to establish the ground of insanity.

Excessive Or Unusual Violence:

The brutality or the ferociousness of the act by itself cannot lead to the conclusion of insanity. Crime cannot be excused by its own atrocity. In order to determine whether the conduct of the accused was an insane act, one must look beyond or outside the act or crime itself for evidence as to how much the accused acted with knowledge.

Insanity Under Criminal Procedure Code:

Under the Criminal Procedure Code,1973 unsoundness of mind comes under section 464 and 465, which states that when an issue as to unsoundness of mind of an accused person is raised the court is bound to enquire it begins to record evidence.

It says that when a magistrate while conducting an inquiry feels that the person is of unsound mind and consequently, incapable of making his defence, he may ask a medical officer to examine the person and postpone the trial of the case.

Position In Other Countries:

Insanity Under American Law:

In regards to defence of insanity in the United States of America, Underhill's Criminal Evidence has the following to say:

Insanity is everywhere a defence to a charge of crime, for without a sound mind there can be no criminal intent. The existence, character and extent of insanity are ordinarily questions of the fact for the jury, and a defendant who has offered proof of his insanity is entitled to an instruction that he may be found not guilty by reason of insanity.

The authorities are not agreed on the legal test for determining insanity. Most of the states have adopted the right and wrong test, as set forth by the House of Lords in the leading case of McNaughten in 1843.

Insanity Under The English Law:

The English law is also based on the Mc'Nachten rule. The English law on insanity is thus:

“where it can be shown that a person at the time of his committing or omitting an act, the commission or omission of which would otherwise be criminal, was labouring under such a defect of reason, from the disease of the mind, as not to know the nature and quality of the act or omission, or as not to know that what he was doing was wrong, then such a person is not in law responsible for his act.

Insanity Under Swiss Law

Section. 10 of the Swiss Penal Code states that ‘any person suffering from a mental disease, idiocy or serious impairment of his mental faculties, who at the time of committing the act is incapable of appreciating the unlawful nature of his act or acting in accordance with the appreciation may not be punished'.

Insanity Under The Law Of France:

Penal Code of France, art. 64 provides that ‘there is no crime or offence when the accused was in state of madness at the time of the act or in the event of his having been compelled by a force which he was not able to resist'.

Case Laws

State Of MP V. Ahamdullah

Subject: The burden of proof that the mental condition of the accused was, at the crucial point of time, such as is described by sec 84, IP code lies on the accused who claims the benefit of this exemption.

Facts: In this case the accused had murdered his mother in law to whom he bore ill-will in connection with his divorce.It was proved that he did the act at night having got into the house by scaling over a wall with the aid of a torch light and entered the room where the deceased was sleeping. All this showed that the crime was committed not in a sudden mood of insanity, but one that was preceded by careful planning and exhibiting cool calculation in execution and directed against a person who was considered to be his enemy. Then again, there was a mood of exultation which the accused exhibited after he had put out her life.

Judgement: In these circumstances the Supreme Court rejecting his plea of insanity, convicted the accused of the offence of murder (setting aside the acquittals of both the session court and the high court), and sentenced him to rigorous imprisonment for life.

Ayyangar J said thus:

In the normal case, the proper punishment for the heinous and premeditated crime committed with human brutality would have been a sentence of death. But taking into the account the fact that the accused has been acquitted by the session's judge, an order which has been affirmed by the high court – we consider that the ends of justice would be met if we sentence the accused to rigorous imprisonment for life.

Dayabhai Chhaganbhai Thakkar V. State Of Gujarat

In this case, the accused was charged and convicted under the IPC, s. 302 for the murder of his wife. The accused killed his wife with wife by inflicting her with 44 knife injuries on her body. The accused raised the plea of insanity at the trial court.

Trial court however rejected the contention on the ground that the statements made to the police immediately after the incident did not showed any sign of insanity. This conviction was confirmed by the high court. The accused made an appeal to the Supreme Court. The Supreme Court also upheld the conviction of the accused and laid down certain criteria according to which an accused in entitled to the defence under the provision. It said that in determining whether the accused has established his case under the purview of Indian Penal Code, 1860, s. 84, ‘the court has to consider the circumstances which preceded, attended and followed the crime. The crucial point of time for determining the state of mind of the accused is the time when the offence was committed. The relevant facts are motive for the crime, the previous history as to mental condition of the accused, the state of his mind at the time of the offence, and the events immediately after the incident that throw a light on the state of his mind'.

Ratanlal V. State Of MP

The appellant on 22 January 1965, set fire to the grass lying in the khalyan of Nemichand. On being asked why he did it, the accused said; ‘I burnt it; do whatever you want'. The accused was arrested on 23 January 1965. He was referred to a mental hospital. The psychiatrist of the hospital reported that the accused remained silent, was a case of maniac depressive psychosis, and needs treatment. The report declared the accused to be a lunatic in terms of the Indian Lunatic Act, 1912The issue before the courts was whether insanity might be used as defence against a charge of mischief by fire with intent to cause damage under the IPC, s. 435. The crucial point in this case was whether unsound mind may be established at the time of commission of the act. The Supreme Court held that the person was insane and acquitted him.

Hazara Singh V. State

In this case, Hazara Singh was under a delusion that his wife was unfaithful to him. One day, being disturbed by those thoughts, he caused her death by pouring nitric acid over her. Medical evidence showed that he knew what he was doing and had the ordinary knowledge of right and wrong. He was convicted for murder.

Bhikari V. State Of Uttar Pradesh

It is not for the prosecution to establish that a person who strikes another with a deadly weapon was incapable of knowing the nature of the act or of knowing that what he was doing was either wrong or contrary to law. Every one is presumed to know the consequences of his act. Similarly everyone is also presumed to know the law. These are not facts that the prosecution has to establish. It is for this reason that sec 105 of The Evidence Act places upon the accused person the burden of proving the exception upon which he relies.

Undoubtedly, it is for the prosecution to prove beyond the reasonable doubt that the accused had committed the offence with the requisite mens rea. Once that is done a presumption that the accused was sane when he committed the offence would arise. This presumption is rebuttable and he can rebut it either by leading evidence adduced in the case whether by prosecution or by the accused and when the reasonable doubt is created in the mind of the court as regards one or more of the ingredients of the offence including mens rea of the accused, he would be entitled to be acquitted.

In the present case, there is evidence that up to the time of occurrence he (accused) has been doing with his cultivation. There is no evidence on record to prove the characteristic of his habit from which it could be concluded that he was acting like an insane man. Before the commission of the crime he did not beat any person. On the other hand, few months before occurrence the accused admittedly picked up quarrel with mangali and Bhaiya Lal and had given threats to make their family extinct. An insane person could not have done so like a sane person. Further on the date of the occurrence many children were playing including his own cousin sister. But first of all he gave a sickle blow only to Babu ram and other children of the family of mangali and babul al and not to any other child. This shows that he did not act under the influence of insanity but only with some previous deliberation and preparation. It is further in evidence that he had given threats to the witnesses. He beat Hiralal only when he tried to stop the act of beating of children of mangali and Bhaiya Lal's family with whom he had picked up quarrel previously. Lastly, a sense of fear prevailed in hi and that is why he acted as a sane man by running and then escaping by jumping into ganges river. So all these circumstances lead to one conclusion that he was not insane and he had acted like a sane man and with some motive.

Held: death sentence was upheld.

Sant Bir V. State Of Bihar

it is not possible as to why the state government should have insisted before releasing the petitioner from the jail when the petitioner was found to be completely recovered and completely fit for discharge and there was absolutely no warrant or justification in law to detain him.

The result was that the petitioner continued to rot in jail for a further period of ten years, though he was fully recovered and there was no reason or justification to continue his detention in the jail. It is shocking that a perfectly sane person should have been incarcerated within the walls of the prison for almost 16 years without any justification in law whatsoever.

Held: The Supreme Court further observed that it should be a matter of shame for the society as well as the administration to detain a person in jail for over 16 years without authority of law.

Tukappa Tamanna Lingardi V. State Of Maharashtra

In a Bombay case a woman, the sister of the accused reported at the police station that he had come to banda weekly bazaar on that day, which was Monday, for selling potatoes and onions and further, that one person by the name ajjappa (victim) had quarrelled with her over the purchase of goods. The ASI of police who was on duty could not follow the language of the woman who was accompanied by the accused, the ASI sent a constable to bring the PS., the person complained against by the woman. But in the presence of the said constable suddenly the accused attacked the deceased and beheaded him. If transpired in the evidence that he accused had the fits of lunacy and, while in such fits, he used to say that a tiger was coming to eat him or to kill him. He used to hear the voice of the tiger and used to refuse to take his food. The accused used to have sleepless nights and if at all he was asleep, he used to get up and run away under the stress of fear from the tiger. On the date of the offence, the appellant was wandering in the forest of a heavy sickle (pal koyta) expecting a tiger to come. After a thorough analysis of the evidence and circumstances, the high court held that the accused was entitled to the protection of section 84, IPC.

Baijanti V. State

The accused was suffering from TB and stomach pain for the last sometimes and one day along with her infant jumped into the well in which incident the child lost her life but the lady accused was taken out alive. On being prosecuted u/s 302 she pleaded insanity but the court refused as she had no kind of mental ailment at the time of committing the crime. However she was said to have committed the act with the knowledge that the death was likely to be caused thereby. Hence her conviction was altered from u/s. 302 to one u/s 304 for committing the offence of culpable homicide not amounting to murder.

Srikant Anandrao Bhosale V. State Of Maharashtra

The circumstances that stand proved in the case are:

The appellant had a family history – his after her was suffering from psychiatric illness. The cause of ailment was not known – but heredity plays a part. The appellant was also being treated for unsoundness of mind since 1992 and was diagnosed as suffering from paranoid schizophrenia. Within a short span, soon after the incident from 27th June to 5th December, 1994, he had to be taken for treatment of ailment 25 times to the hospital. The appellant was also under regular treatment for the mental ailment. The And the fact of the killing in day light shows that no attempt to hide or run away was made.

The plea of insanity was thus proved. Hence the conviction and sentence of the appellant cannot be sustained.

Babasaheb Thombre V. State Of Maharashtra

In the present case the accused was found guilty of committing murder of his wife. He was convicted for committing offence punishable under section 302 of the Indian penal code and is sentenced to suffer imprisonment for life by the Additional Session's Judge. The post mortem report was prepared by an autopsy surgeon who stated that the cause of the death of the wife of the accused was a shock due to the head injury with laceration of the brain.

The accused pleaded insanity as a defence and stated that he was suffering from schizophrenia. But the evidence proved that he was not suffering from any kind of mental illness and was in full control of all his cognitive faculties prior to, at the time and after the commission of the offence.

The appeal was thus dismissed in the higher court and the accused was convicted for murder.

Conclusion And Suggestions

The Indian Law on insanity is based on the rules laid down in the Mc'Naghten case.

However, the Mc'Naghten rules have become obsolete and are not proper and suitable in the modern era.

The Mc'Naghten rules is based on the entirely obsolete and misleading conception of nature of insanity, since insanity does not only affect the cognitive faculties but affects the whole personality of the person including both the will and the emotions. The present definition only looks at the cognitive and moral aspects of the defendant's actions but ignores the irresistible impulse that may be forcing him to commit that act. An insane person may often know the nature and quality of his act and that law forbids it but yet commit it as a result of the mental disease. The Law Commission of India in its 42nd report after considering the desirability of introducing the test of diminished responsibility under IPC, s. 84 gave its opinion in the negative due to the complicated medico-legal issue it would introduce in trial. It is submitted that the Law Commission's view needs modification since it is not in conformity with the latest scientific and technological advances made in this direction. There are three compartments of the mind - controlling cognition, emotion and will. IPC, s. 84 only exempts one whose cognitive faculties are affected. The provision is regarded as too narrow, and makes no provision for a case where one's emotion and the will are so affected as to render the control of the cognitive faculties ineffectual. The Courts must also adopt a broader view of the Insanity and introduce the concept of diminished responsibility.

The Indian Government may also look at the provisions of the other countries relating to insanity. Swiss Penal Code, s. 10 states that ‘any person suffering from a mental disease, idiocy or serious impairment of his mental faculties, who at the time of committing the act is incapable of appreciating the unlawful nature of his act or acting in accordance with the appreciation may not be punished'. This provision is much broader and is better suited for the defence of insanity. The researcher submits that the defence of insanity is too narrow and must be amended to suit the present demands.


Books Referred:

  • P Srivastava, “Principles of Criminal Law”, 4th ed., 2005.

  • PSA Pillai, “Criminal Law”, 9th ed., 2007.

  • K S N Murthy and K V S Sarma, “Criminal Law”, 1st ed., 2001.

  • ND Basu, “Indian penal code”, 9th ed., vol 1, (2nd Ind. Rep.), 2006.

  • R P Kathuria. “Supreme court on criminal law”, vol.3, 5th ed., 1996.

  • Ratanlal and Dhirajlal, “ Indian penal code”, 29th ed., (2nd Ind. Rep.), 2004.

  • J W Cecil Turner, “outlines of criminal law”, 19th ed., 2002.

  • John Kaplan and Robert Weisberg, “criminal law”, 2nd ed., 1991.

Websites Referred: