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Unsoundness of Mind (IPC)

Updated: May 12

Unsoundness of Mind (IPC)
Unsoundness of Mind (IPC)


Sec. 84: Act of Lunatic [Defence of Insanity] [Unsoundness of Mind]

Sec. 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 insanity defence is primarily utilised in criminal trials, predicated on the premise that, at the time of the offence, the defendant was grappling with severe mental illness, rendering them incapable of comprehending the nature of their actions and discerning between right and wrong behaviour.

Consequently, they are deemed legally non-accountable for the crime. Insanity serves as a fundamental defence, as individuals afflicted with mental illness lack the capacity for culpable intent; they are unaware of their actions.

The following legal maxims/principles are relevant in the context of the defence of insanity:

  • No culpability can be fastened upon insane persons as they have no free will {Furiosi nulla voluntas est).

  • A madman is punished by his madness alone {Furiosus furor sui punier).

  • A mad man is like a person who is absent {Furiosus absentis loco est).

The term "unsoundness of mind" remains undefined within the Code. Courts have typically equated this term with insanity, although "insanity" itself lacks a precise definition and encompasses various meanings across different contexts, delineating varying degrees of mental disorders.

This section stipulates that an individual, due to unsoundness of mind, is incapable of controlling their conduct or exercising rational judgement regarding the nature of their actions, thus absolving them of legal responsibility for those actions.

The provision operates on the principle that an action does not constitute an offence unless accompanied by a guilty intention ("actus non facit reum, nisi mens sit rea").

An "idiot" is someone whose mental faculties have been impaired since birth due to a perpetual infirmity, lacking lucid intervals.

A "lunatic" experiences periodic episodes of mental disorder, alternating with periods of lucidity, as described by older English writers.

During episodes of mental disorder, lunatics are as legally irresponsible as individuals with permanent mental disorders, referred to as "madness."

Madness is characterised by its permanence. Lunacy and madness are termed "acquired insanity," while idiocy is termed "natural insanity."

An individual rendered non compos mentis by illness is unable to comprehend their actions or their consequences, particularly during fits of delirium induced by prolonged illness or heavy drinking.


Tests/Principles to determine Insanity of a Person

  1. English Law

In the renowned English case known as McNaughten's case (1843) 10 Cl & F 200, Mr. McNaughten suffered from a longstanding "persecution mania." He believed that a group of individuals was stalking him, slandering him, and obstructing his employment opportunities.

One day, at a railway station, he shot a man named Mr. D, mistaking him for Sir Robert Peel, the Prime Minister of England, whom he held responsible for his misfortunes. Some witnesses testified that he acted under an uncontrollable impulse, while others claimed he was insane.

The jury acquitted him based on insanity, causing a stir in England. The opinions rendered in this case laid the groundwork for modern insanity laws. The House of Lords established four key propositions:

  • Every individual is presumed to be sane and possessed of sufficient reason to be accountable for their crimes until proven otherwise to the court's satisfaction.

  • To establish a defence based on insanity, it must be convincingly demonstrated that at the time of the act, the accused was suffering from a lack of reason or a mental illness, rendering them unaware of the nature and quality of their actions, or, if aware, unaware that their actions were wrong.

  • If the accused knew their actions were wrong and violated the law, they are punishable. The test is their ability to distinguish right from wrong, not in the abstract, but regarding the specific act committed.

  • When a criminal act is committed under an insane delusion that conceals the true nature of the act, the accused is held accountable to the same extent as if the circumstances were as they imagined. For instance, if under delusion, they believe another person is attempting to take their life and they kill that person in supposed self-defence, or if they believe they are lawfully executing a judicial sentence by killing another person.

Additionally, if the accused suffers from a partial delusion, they are held responsible for the crime as if the delusion were based on reality. In other words, they are accountable for the actions committed.

  1. Indian Law

Section 84 of the Indian Penal Code is rooted in the principles laid down in the M'Naghten rules, albeit using the broader term 'unsoundness of mind' instead of 'insanity'.

While the irresistible impulse is not a recognized defence in criminal prosecutions under Indian and English law, it may be considered to mitigate punishment if proven before a court.

According to Section 84, the accused must have been suffering from a mental illness during the commission of the act.

Moreover, there should be a loss of reasoning ability, implying that the person was incapable of understanding the nature of the act or recognizing its wrongfulness or contrariness to the law.

The phrase 'Incapable of knowing the nature of the act' implies that the individual should not merely understand whether an act is right or wrong, but should be inherently unable to discern its nature.

This incapacity refers to an organic inability rather than a mistaken belief stemming from a distorted perception.

Furthermore, a person may understand the nature of the act but not its moral wrongness or contrariness to the law. In such cases, the accused may still be protected under Section 84.

Insane delusions, akin to lunacy, are crucial factors in assessing criminal responsibility. If a person under an insane delusion commits an offence, their culpability depends on the nature of the delusion.

Similarly, cases of delirium, whether induced by illness or intoxication, are considered under Section 84, provided the individual was unaware of their actions.

When determining insanity, the accused's mental state before and after the offence, including any history of previous insanity, must be considered.

Medical/Legal insanity 

Mere unsoundness of mind alone does not suffice to invoke the exception provided by Section 84.

Even if a person is deemed medically insane, if they were aware that their actions were wrong, they cannot be exonerated under Section 84.

The legal concept of insanity focuses solely on impairment of cognitive faculties; cases where only emotions or will are affected do not fall under this exception.

Insane impulses are not considered a defence under Section 84 because criminal law aims to compel individuals to control both their rational and irrational impulses.

While impaired cognitive faculties may qualify for the defence of unsoundness of mind, mere agitation of mind or uncontrollable impulses does not necessarily indicate a lack of mental capacity.

Additionally, conditions such as "moral insanity" or weak intellect do not serve as defences. It's important to note that insanity is distinct from eccentricity or unconventional behaviour.

Medical Insanity v Legal Insanity

A clear distinction exists between legal insanity and medical insanity. While medical insanity refers to a person suffering from a mental disorder, legal insanity, which is the focus of the insanity defence, requires not only the presence of a mental illness but also a loss of reasoning power.

Legal insanity pertains solely to the mental state of an individual at the time of committing a crime and is a legal concept, independent of psychiatric diagnoses.

Legal insanity entails a complete loss of cognitive faculties, whereas medical insanity does not necessarily involve a total loss of understanding.

While legal insanity serves as a complete defence under the Indian Penal Code, medical insanity can be utilised as evidence to establish legal insanity but does not provide protection under the IPC.

Mere abnormalities of the mind, partial delusions, or compulsive behaviours of psychopaths or sociopaths do not qualify for protection under Section 84. Simply being conceited, eccentric, or experiencing irregular behaviour due to physical or mental ailments does not suffice to invoke Section 84.


Illustrative Cases

In the case of Emperor v Gedka Gowla (1937) 16 Pat 333, the accused stood trial for the murder of his wife and children. The court emphasised the need to look beyond the mere act itself to determine the extent of the accused's understanding of it. The crucial aspect under examination was whether the accused was aware of the nature of the killing and intended to carry it out. Specifically, the court sought to ascertain whether the accused recognized that he was taking the lives of human beings, or if he was under a disorder that rendered him oblivious to this fact. It was determined that the absence of motive, secrecy, pre-arrangement, and accomplices was insufficient to indicate that the accused suffered from the type of unsoundness of mind described in Section 84.

Several post-incident actions of the accused pointed to his sanity:

  • He demonstrated awareness of his actions by threatening his brother-in-law about the killings and expressing intent to harm him.

  • Seeking poison from a neighbour to end his life, citing his actions of having harmed others.

  • Demonstrating clarity of thought during a confession before the magistrate.

  • Evidence showed that the accused had taken preparatory steps by closing the doors before attacking the victims.

Based on these observations, it was concluded that the accused comprehended the nature of his actions and was fully aware, akin to any sane individual. The court emphasised that exemption from criminal liability is not warranted solely on the basis of being subject to insane impulses, especially when cognitive faculties remain unimpaired.

Only when there is a significant impairment of cognitive faculties can unsoundness of mind serve as a basis for exemption from criminal liability.

In the case of Queen Empress v Kader Nayser Shah (1896) IA 23 Cal 604, the accused had been grappling with mental derangement following the destruction of his home by fire. He frequently complained of headaches. One day, a person entrusted his son to the care of the accused. Upon returning, he discovered the accused hiding in a jungle while his son lay dead. The accused was charged with murder, but the trial was postponed for approximately a year due to his unfit mental state to stand trial.

The court deliberated that while the circumstances surrounding the murder suggested that the accused was not devoid of reasoning power to discern right from wrong (evident by his action of hiding in the jungle), they also indicated that he was likely experiencing some form of mental derangement at the time. Additionally, the absence of any rational motive further complicated the case, rendering it a "borderline" situation.

In the case of Queen v Lakshman Dagdu (1886) 10 Bom 512, A was suffering from fever, which occasionally induced paroxysms that left him bewildered and unconscious. During one such episode, A killed his children because their crying annoyed him. Subsequently, he retired to bed and fell asleep. The accused had exhibited no prior signs of insanity.

The court determined that A was guilty of murder. At the time of the killings, he was not experiencing any paroxysms and was fully aware of his actions. While it was acknowledged that, based on medical assessments alone, the accused might have been acquitted, the pertinent inquiry was whether this standard was legally applicable.

Given the absence of evidence indicating that the act was committed during a state of delirium, the court upheld the conviction.

In the case of Lakshmi v State (AIR 1959 All 534), the accused, who was a drug addict, was convicted for the murder of his step-brother, with whom he had strained relations. The accused had a history of making demands for money from his relatives, including his step-brother. A few days before the incident, there was an altercation between the accused and his step-brother. During the altercation, the accused assaulted his step-brother with a pharsa, prompting the latter to raise an alarm. Upon the arrival of bystanders, the accused fled the scene, taking the pharsa with him. 

The accused claimed that he was prone to recurring fits of insanity at short intervals. However, the High Court determined that there was evidence of motive against the accused.

Additionally, his conduct both before and at the time of the incident, as well as his behavior following the incident, indicated that he was not entitled to the benefit of Sec. 84.

For instance, his attempt to flee after assaulting his step-brother demonstrated an intention to evade arrest. Furthermore, during the trial, the accused exhibited clear-headedness, further undermining his claim of insanity.


Leading Case Laws

T.N. LAKSHMAIAH v STATE OF KARNATAKA [(2002) 1 SCC 219]: In T.N. Lakshmaiah v State of Karnataka, the Supreme Court clarified the burden of proof in cases of insanity. The accused, who murdered his wife and son, claimed insanity as a defence. However, his conduct before and during the incident, as well as afterward, indicated otherwise. He showed signs of full normalcy, such as applying for bail after the incident, leading the court to conclude that he was not entitled to the benefit of Sec. 84.

The court reiterated the burden of proof in insanity cases:

  • The prosecution must prove beyond reasonable doubt that the accused committed the offence with the required intent.

  • There is a rebuttable presumption that the accused was sane when the crime was committed. The accused can rebut this by presenting relevant evidence, but the burden is no higher than that in civil proceedings.

  • Even if the accused cannot conclusively establish insanity, if there is reasonable doubt about one or more elements of the offence, including intent, the court may acquit.

  • The accused must meet a special burden to prove insanity, but this does not shift the general burden of proof from the prosecution.

It was emphasised that every person is presumed sane unless proven otherwise, and mere assertion by the accused is insufficient to claim the benefit of exceptions under Chapter IV of the IPC.

SHRIKANT ANANDRAO BHOSALE v STATE OF MAHARASHTRA [(2002) 7 SCC 748] - In Shrikant Anand Rao Bhosale v State of Maharashtra, the appellant, a police constable, was charged with murdering his wife during a quarrel. He pleaded insanity at the time of the crime. The prosecution argued that the murder resulted from extreme anger, not unsoundness of mind, as the appellant had a history of anger issues.

However, evidence showed that the appellant had a family history of psychiatric illness and was diagnosed with paranoid schizophrenia. He was under regular treatment and had been hospitalized multiple times for his mental ailment.

The motive for the murder was weak, and the appellant made attempts to hide afterward. The court concluded that the appellant was likely under a delusion due to his mental ailment at the time of the crime.

Therefore, he was incapable of knowing the nature of the act, entitling him to the benefit of Sec. 84 of the IPC.


Criticism of Sec. 84, IPC

In law, both children and individuals deemed insane receive special treatment under various provisions. While legislation like the Protection of Children from Sexual Offences Act, 2012 (POCSO) addresses the unique needs of children, there are no similar provisions for the insane.

Despite similarities in requirements, insanity pleas are often handled by judges without adequate understanding of psychological principles. 

There is a significant communication gap between courts and medical evaluators, with expert opinions often constrained to simple 'yes or no' answers that fail to capture the complexities of insanity.

Proceedings focus on whether the accused committed the act rather than exploring the underlying psychological factors.  There is an urgent need for modifications to the insanity defence provision to ensure fairness and justice.

This includes incorporating emotional, medical, and circumstantial aspects into Section 84 to provide a more comprehensive understanding of insanity.


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