1. 1
INSANITY AS A DEFENCE
Ankit Kejriwal♠
INTRODUCTION
A crime is a voluntarily act which is an outcome of an intent to cause an evil consequence1
. There
are certain essentials of crime. The actor must possess the following conditions2
:
(1) free will;
(2) intelligence to distinguish between good and evil;
(3) knowledge of facts upon which the good and evil of an act may depend; and
(4) knowledge that the act is prohibited by law.
Mens Rea is an essential element in every crime. There may be no crime of any nature
without an evil mind. There must be a mind at fault to constitute a criminal act. The concurrence of
act and guilty mild constitutes a crime3
. This theory has its basis in the latin maxim ‘actus non facit reum
nisi mens sit rea’ which means that the act does not makes one guilty unless he has a guilty intention.
Lord Diplock in the case of Swet vs. Parsley4
said, ‘An act does not make a person guilty of a crime unless his
mind be so guilty’.
But in the case of insane person, he may not understand the nature of the act. He does not
have the sufficient mens rea to commit a crime. Since a criminal intent is an indispensible element in
every crime, a person incapable of entertaining such intent may not incur guilt5
. An insane person is
not punished because he does not have any guilty mind to commit the crime. 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 (IPC), s. 84, based on the Mc’Naghten rules.
♠
Student, NALSAR University of Law, Hyderabad, Andhra Pradesh.
1 B.M. Gandhi, ‘Indian Penal Code’, 2nd ed., 2006, at pp. 125.
2 Huda: The Principles of the Law of Crimes in British India, (1982) pp. 217.
3 Srivastava, O.P., Principles of Criminal Law, 4th ed., 2005 at pp 228.
4 1970 AC 132.
5 Bishop Criminal law as quoted in Basu’s Indian Penal Code, 9th ed. 2006, Vol. 1, pp. 314.

2. 2
In the research paper, the researcher tries to differentiate between legal insanity and medical
insanity. The researcher covers both English law and Indian law on insanity. The researcher will also
compare the Indian law with law of other countries and will try to figure out if there is any scope for
improvement in the law or not.
INSANITY: MEANING
The meaning of insanity in civil law, medicine and neuroscience is different from its meaning in
criminal law.
Insanity in Law
Insanity or unsoundness of mind is not defined in the act. It means a disorder of the mind, which
impairs the cognitive faculty; that is, the reasoning capacity of man to such an extent as to render
him incapable of understanding consequences of his actions. It means that the person is incapable of
knowing the nature of the act or of realising that the act is wrong or contrary to law6
. A person,
although of unsound mind, who knows that he is committing an unlawful act, may not get the
benefit of IPC, s. 84. The nature and extent of the unsoundness must be so high so as to impair his
reasoning capacity and that he may not understand the nature of the act or that it is contrary to law.
It excludes from its preview insanity, which might be caused by engendered by emotional or
volitional factors.
There are four kinds of person who may be said to be non compos mentis (not of sound mind)
(1) an idiot – an idiot is one who from birth had defective mental capacity. This
infirmity in him is perpetual without lucid intervals;
(2) one made so by illness – by illness, a person is made non compos mentis. He is
therefore excused in case of criminal liability, which he acts under the influence of
this disorder;
6 Basu’s Indian Penal Code, 9th ed, 2006.

3. 3
(3) a lunatic or a madman – lunatics are those who become insane and whose incapacity
might be or was temporary or intermittent. A lunatic is afflicted by mental disorder
only at certain period and vicissitudes, having intervals of reason7
; and
(4) one who is drunk – this is covered under IPC, s. 85.
Insanity in Medical Terms
There is a difference between the medical definitions of insanity. According to medical science,
insanity is a disorder of the mind that impairs the mental facilities of a man8
. Insanity is another
name for mental abnormalities due to various factors and exists in various degrees9
. Insanity is
popularly denoted by idiocy, madness, lunacy, to describe mental derangement, mental disorder and
all other forms of mental abnormalities known to medical science. Insanity in medical terms
encompasses much broader concept than insanity in medical terms.
Therefore, the scope of the meaning of insanity in medical terms is much wider when
compared to its legal meaning.
ENGLISH LAW ON INSANITY
The English law on insanity is based on the Mc’Naghten rules.
Development of the Law
The insanity defence has a long history, and is evolved after many tests that have been tried and
tested.
7 Russell, Vol. 1, (12th ed.), pp. 105.
8 KD Gaur.
9 Srivastava, R.C., Law Relating to Crime and Punishment, 2006, Manav Law House, Allahabad.

4. 4
Wild Beast test: It was the first test to check insanity that was laid down in the case of
Arnold Case in 1724. Justice Tracy, a 13th
century judge in King Edward’s court, first formulated the
foundation of an insanity defense when he instructed the jury that it must acquit by reason of
insanity if it found the defendant to be a madman which he described as ‘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’10
.
Good and Evil test: This test was laid down in the case of R vs. Madfield. The test laid down
in this case is ‘the ability to distinguish between good and evil’. In this case, the accused was charged
for treason for 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 test: The law relating to the defence of insanity is to be found in the rules set
out in Mc’Naghten11
that delineate the circumstances in which an accused will be held not to have
been legally responsible for his conduct.
The Origin of the Rules on the Insanity Plea
Daniel Mc’Naghten was found to be insane and acquitted on a charge of murdering Sir Robert
Peel’s private secretary, it being his intention to kill Peel. He was committed to the hospital but there
was public outcry about the leniency of the verdict. The matter was debated in the House of Lords
where it was decided to seek the opinion of the judges on legal principles relating to insanity. The
rules laid down were:
(1) everyone is to be presumed sane and to possess a sufficient degree of reason to be
responsible for their crimes until contrary is proved to the satisfaction of the jury;
(2) to establish a defence of insanity, it must be clearly proved that at the time of
committing the act, the accused was laboring under such a defect of reason, from the
disease of the mind, as not to know he was doing what was wrong12
;
10 Christopher Slobogin, An End to Insanity: Recasting the Role of Mental Disability in Criminal Cases,
86 Va. L. Rev. 1199, 1208 (2000).
11 (1843) 10 Cl & F 200.
12 Michael Allen, ‘Textbook on Criminal law’, 7th ed. 2003, at pp. 123.

5. 5
(3) as to his knowledge of the wrongfulness of the act, the judges said: ‘if the accused
was conscious that the act was one which he ought not to do and the same time the
act was contrary to the law of the land, he is punishable; and
(4) Where a person under insane delusion as to existing facts commits an offence in
consequence thereof, criminality must depend on the nature of the delusion. If he
labours under partial delusion only, and is not in other respects insane, he must be
considered in the same situation as to responsibility as if the facts with respect to
which the delusion exists were real.
The Halsbury’s Laws of England explain that where on a criminal charge, it appears that, at
the time of the act or omission giving rise to the offence alleged, the defendant was laboring under a
defect of reason owing to a disease of mind so as not to know the nature and quality of his act, or, if
he knew this, so as not to know that what he was doing was wrong, he is not regarded in law as
responsible for the act. The question whether, owing to a defect of reason due to the disease of the
mind, the defendant was not responsible for his act is a question of fact to be determined by the
jury. Where the jury finds insanity is made out the verdict takes place in the form of not guilty due to
insanity13
.
The Constituent elements of the Defence
There are three conditions to be satisfied in any case where a defence of insanity is raised:
(1) the accused was suffering from the disease of the mind – disease of the mind is a
legal term and not a medical term. The law is concerned with the question whether
the accused is to held legally responsible for his acts. This depends on his mental
state and its cause complying with legally defined criteria. Lord Denning defined it as
‘any mental disorder which has manifested itself in violence and is prone to recur is a
disease of the mind. At any rate it is the sort of disease for which a person should be
detained in hospital rather than be given an unqualified acquittal’. The leading
decision on what constitutes a disease of the mind was given in the case of Sullivan14
13 Halsbury’s Laws of England, 4th ed., Vol. 11, para 30, pp. 27-28, as quoted in Justice Y.V.
Chandrachud (ed.), Ratanlal and Dhirajlal, ‘Indian Penal Code’, 29th ed. Rep. 2004, at pp. 320.
14 (1984) A.C. 156 at 172 as quoted in Alan Reed and Peter Seago, ‘Criminal law’, 1999.

6. 6
in which a distinction was drawn between insane and non-insane person automatism.
Lord Diplock defined disease of the mind as ‘mind in the Mc’Naghten rules is used
in the ordinary sense of the medical faculties of reason, memory and understanding.
If the effect of the disease is to impair these faculties so severely as to have either of
the consequences referred to in the latter part of the rules, it matters not whether the
etiology of the impairment is organic, as in epilepsy, or functional, or whether the
impairment is itself permanent or is transient and intermittent, provided that it
subsisted at the time of commission of the act’;
(2) this disease gave rise to a defect of reason: where the defence of insanity is to
succeed, the disease of the mind must give rise to a defect of reason. The reasoning
power of a person must be impaired. The defendant must show that he was suffering
from such defect of reason that he did not know the nature and quality of the act he
had committed, or if he did know, that he did not know that what he was doing was
wrong. If the accused is relying on the second limb, he must show proof that he did
not know that it was legally wrong; and as a result, he either did not know that what
he was doing was wrong: If the accused’s defect of reason is to be effective in
establishing the defence of insanity, the insanity must affect his legal responsibility
for his conduct as such he is not able to realise that what he was doing is wrong.
Wrong here means something that is contrary to law15
.
Where the person knows the nature or quality of the act and knows he was doing wrong, then
the fact that he was acting under a strong impulse will not entitle him to a defence under the rules.
In 1916, in the case of R vs. Codere16
, the court of criminal appeal explained the principles:
(1) an objective moral test must be applied in cases where insanity is pleaded. The test of
insanity is ‘the objective standard adopted by the reasonable men’;
(2) an act is wrong according to that standard if it is punishable by law;
15 R vs. Windle (1952) 2 QB 826 as quoted in Harris, ‘Criminal law’, 22nd ed. 1st Indian Reprint 2000, at
pp. 92.
16 (1916) 12 Cr.App.R. 21.

7. 7
(3) the accused must be deemed ‘to know he was doing what was wrong’ if he was aware
that the act was one which was punishable; and
(4) the words ‘nature and quality’ do not refer to the moral aspects of what the offender
was doing but solely to the physical facts.
Criticism of the Mc’Naghten Rule
The British Royal Commission on capital punishment that made its report in 1953, and criticised the
rule. Experienced lawyers and doctors also criticised the rule. Doctors with experience on mental
disease ‘have contended that the Mc’Naghten test 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. Many scholars
criticised the Mc’Naghten test because it only looked at the cognitive and moral aspects of the
defendant’s actions17
. An insane person may therefore often know the nature and quality of his act
and that law forbids it but yet commit it as a result of the mental disease18
. The Royal Commission
came to the conclusion that the test of insanity laid down in Mc’Naghten rules is defective and the
law must be changed.
Although the Mc’Naghten rules still hold the field in England despite the recommendations
of the law commission, a new defence to murder known as ‘diminished responsibility’ was
introduced by the Homicide Act, 1957. Provisions of the enactment states that:
(1) where a person kills or is in the party of killing another, he will not be convicted of
murder if he was suffering from such abnormality of mind as substantially impaired
his mental responsibility for his acts and omissions in doing or being a party to the
killing;
(2) a person who but for this provision would be liable, whether as principal or as
accessory, to be convicted of murder will be liable instead to be convicted of man
slaughter.
17 Gerald Robin, The Evolution of the Insanity Defense, 13 J. Contemp. Crim. Just. 224, 226 (1997).
18 Law Commission report, pp. 90.

8. 8
INDIAN LAW ON INSANITY
The Indian law relating to insanity has been codified in the IPC, s. 84 contained also
the general exceptions.
Indian Penal Code, s. 84: ‘Acts 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’.
IPC, s. 84 and the Mc’Naghten rule:
IPC, s. 84 deals with the law of insanity on the subject. This provision is made from
the Mc’Naghten rules of England. In the draft penal code, Lord Macaulay suggested
two sections (66 and 67), one stating that ‘nothing is an offence which is done by a
person in a state of idiocy’ and the other stating that ‘nothing is an offence which a
person does in consequence of being mad or delirious at the time of doing it’ to deal
with insanity. The Law Commissioners in replacing these two provisions by IPC, s.
84 have adopted a brief and succinct form of the Mc’Naghten rules. It has been
drafted in the light of the replies to the second and third questions, which is generally
known as Mc’Naghten rules.
But, IPC, s. 84 uses a more comprehensible term ‘unsoundness of mind’
instead of insanity. Huda says the use of the word ‘unsoundness of mind’ instead of
insanity has the advantage of doing away with the necessity of defining insanity and
of artificially bringing within its scope different conditions and affliction of mind

9. 9
which ordinarily do not come within its meaning, but which nonetheless stand on
the same footing in regard to the exemptions from criminal liability19
.
Ingredients
This provision states that an unsoundness of mind is a defence to criminal charges. It
is accepted as a defence to a criminal charge on the theory that ‘one who is insane
has no mind and may not have the necessary mens rea to commit a crime’20
. The act
of a mad person is unintentional and involuntary, no court may correct him by way
of punishment21
. To invoke the benefit of IPC, s. 84, it must be proved that at the
time of commission of the offence, the accused was insane and the unsoundness of
mind was of such a degree and nature as to fulfill any one of the test laid down in the
provision. These are:
(1) firstly, the accused was incapable of knowing the nature of the act. It
covers two situations, namely, automatism and mistake of fact due to
unsoundness of mind as a defence22
; and
(2) secondly, that the accused was precluded by reason of unsoundness
of mind from understanding that what he was doing was either
wrong or contrary to law. It covers those cases wherein a man by
reason of delusion is unable to appreciate the distinction between
right and wrong23
.
19 Huda, S.S. Principles of Law of Crimes in British India, as quoted in K.D. Gaur,
‘Commentary on Indian Penal Code’, 1st ed. 2006, Universal, pp. 271.
20 Gour, Penal Law of India, 11th ed. Vol. 1, 2000, pp. 602: ‘A mad man has no will’;
Furoisis nulla voluntas east; as quoted in KD Gaur.
21 Ibid.
22 Pillai, K.N. Chandrasekharan, General Principles of Criminal Law, 1st Ed., reprint,
2005, Eastern Book Company, Lucknow.
23 Ibid.

10. 10
The accused is protected not only when, on the account of insanity, he was
incapable of knowing the nature of the act, but also when he did not know either the
act was wrong or it was contrary to the law. He is however, not protected if he knew
that what he was doing was wrong, even if he did not know that it was contrary to
the nature of the law or vice versa24
.
The defence of insanity may be established if it is proved that at the time of
committing the act, the party accused was laboring under such a defect of reason,
from disease of the mind, as not to know the nature or quality of the act he was
doing, or if he did know it, that he did not know that he was doing what was
wrong25
. The benefit of this provision may be taken only if at the time of committing
the crime, the offender by reason of unsoundness of mind was incapable of knowing
the real nature of his act or that the act was morally wrong or contrary to law26
.
The Cuttuck High Court has laid down certain principles in the case of
Sundra Majhi27
:
(1) every type of insanity is not legal insanity; the cognitive faculty must
be so 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 will 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 on the prosecution;
(4) the court must consider whether the accused suffered from legal
insanity at the time when the offence was committed;
24 Geron Ali, (1940) 2 Cal 329 as quoted in Ratanlal And Dhirajlal.
25 Mc’Naughten case.
26 State of Madhya Pradesh vs. Ahmedullah 1961 INDLAW SC 97, AIR 1961 SC 998,
Dahyabhai C. Thakur vs. State of Gujarat 1964 INDLAW SC 409, AIR 1964 SC 1563.
27 1971 Cut LT 565.

11. 11
(5) in reaching such a conclusion the circumstances which preceded,
attended or followed the crime are relevant considerations; and
(6) the prosecution in discharging its burden in the face of the plea of
legal insanity has merely to prove the basic fact and rely upon the
normal presumption of that everyone knows the law and the natural
consequences of his act.
The law on the point has been well summarised by their Lordships of the
Calcutta High Court in Kader Nasayer Shah in the following words: ‘it is only
unsoundness of mind which materially impairs the cognitive faculties of the mind
that may form a ground of exemption from certain responsibility, the nature and
extent of unsoundness of mind required being such a nature would make the
offender incapable of knowing the nature of the act, or that he is doing what is (1)
wrong or (2) contrary to law’28
.
Burden of proof
The principle that the court follows is that ‘every person is sane unless contrary is
proved’29
. The onus of proving insanity is one the person who is pleading it as a
defence. In the case of State of Madhya Pradesh vs. Ahamadullah30
, it was observed that
burden of proof is on the accused. The Supreme Court also upheld the principle in
the case of S.W. Mohammed vs. State of Maharastra31
and said that the accused have to
28 1896 ILR 23 Cal 604 (608) as quoted in Gour, Hari Singh, The Penal Law of India,
Vol. 1, 11th ed., 2002, Law Publishers (India) Pvt. Ltd., Allahabad.
29 Allen, Michael, Textbook on Criminal Law, 7th ed., 2003, Oxford University Press,
London.
30 1961 INDLAW SC, AIR 1961 SC 998
31 AIR 1972 SC 216

12. 12
prove that he is insane. However, this requirement of proof is not heavy as on the
prosecution to prove the offence and is based on balance of probabilities.
It has been criticised that the McNaughton rules of the 19th
century England,
on which IPC, s. 84 is based are outdated since they do not provide protection under
IPC, s. 84 to behaviour out of abnormality of mind, or partial delusion, irresistible
impulse or compulsive behaviour of a psychopath. Court in India also stressed the
need for adopting a more progressive attitude in the application of law related to
insanity. The Indian Law of insanity must be amended and the concept of
diminished responsibility must be inserted.
PROVISIONS OF THE CODE OF CRIMINAL PROCEDURE, 197332
The procedure for the trial of insane person is laid down in the Code of Criminal
Procedure, 1973, Chapter XXV.
Code of Criminal Procedure, 1972, ss. 328 and 329 deals with the procedure
to be followed in case the accused is a lunatic. 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. Code of Criminal Procedure. 1973, s. 330 provides
that when an accused is found to be a lunatic, he will be released on bail provided
that sufficient security is given that he will not harm himself or any other person. If
sufficient security is not given or the court thinks that bail may not be granted, the
accused will be detained in safe custody. Code of Criminal Procedure, 1973, s. 331
provides that when an inquiry is postponed under Code of Criminal Procedure,
32 Code of Criminal Procedure, 1973, ss. 328 to 339.

13. 13
1973, ss. 328 and 329, the magistrate will resume the inquiry at any time after the
person concerned ceases to be of unsound mind. The inquiry will proceed against
the accused when the magistrate thinks that he is capable of making the defence as
per Code of Criminal Procedure, 1973, s. 332. Code of Criminal Procedure, 1973, s.
333 says that when the accused is at the time of the inquiry is of sound mind, but he
was of unsound mind at the time of committing the offence, the Magistrate will
proceed with the case. Code of Criminal Procedure, 1973, s. 334 states that when any
person is acquitted on the ground that at the time of committing the offence, he was
by reason of unsoundness of mind incapable of knowing the nature of the act or that
it is contrary to law, the state will specify whether he committed the act or not. Code
of Criminal Procedure, 1973, s. 338 says that when the person detained under Code
of Criminal Procedure, 1973, ss. 330(2) or 335 and the inspector general certify that
in his judgment, he may be released without danger to himself or any other person,
the state government may order him to be released or to be detained in custody or to
be sent to a public lunatic asylum.
The Code of Criminal Procedure, 1973 also makes favourable provisions for
the infants.
JUDICIAL INTERPRETATION
Ratanlal vs. State of MP33
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,
33 1970 INDLAW SC 2, AIR 1971 SC 778.

14. 14
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, 1912. The 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.
Dayabhai Chhaganbhai Thakkar vs. State of Gujarat34
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 a accused in entitled to the defence
under the provision. It said that in determining whether the accused has established
his case under the perview of Indian Pena lcode, 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’.
34 1964 INDLAW SC 409, AIR 1964 SC 1563.

15. 15
Ashiruddin vs. King35
In this case, Ashruddin had killed his son while acting under the delusion of a dream
believing it to be right. The accused had dreamt that he was commanded by
someone to sacrifice his son of five years. The next morning the accused took his
son to mosque and killed him by thrusting a knife in his throat. The Calcutta High
Court observed that it was a case of insanity under IPC, s. 84 and discharged the
accused from criminal liability. The court said that in order to enable an accused to
obtain the benefit of the aforesaid provision, he must establish any one of the
following three elements
(1) the nature of the act was not known to the accused;
(2) the act was not known by him to be contrary of law; or
(3) the accused did not knew that the act was wrong.
The Bench held that the third element was established by the accused,
namely, that the accused did not knew that the act was wrong. This was obvious on
the ground that the accused was laboring under the belief that the dream was a
reality.
However, this view of the Calcutta High Court was criticised by Allahabad
High Court in the case of Laxmi vs. State36
as ‘it will be open to an accused in every
case to plead that he had dreamt a dream enjoining him to do a criminal act, and
believing that his dream was a command by a higher authority, he was impelled to do
a criminal act, and therefore, he would be protected by IPC, s. 84. It also said that it
was a case of medical insanity and not legal insanity.
35 AIR 1949 Cal 182.
36 AIR 1953 All 534.

16. 16
Hazara Singh vs. State37
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.
POSITION IN OTHER COUNTRIES38
The Criminal Codes of many countries provide for a broader scope for the defence
of insanity. Tasmanian Criminal Code, s. 16 says that an accused may not be
punished if he may not understand the nature of the act or that it was against law.
They may also not be punished if they committed the act under an ‘irresistible
impulse’. 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’. 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’. The American Law Institute suggested that ‘a
person is not responsible for criminal conduct if at the time of such conduct as a
result of mental disease or defect he lacks the substantial capacity either to appreciate
the criminality of his conduct or to confirm his conduct to the requirements of law’.
37 AIR 1958 Punj 194.
38 Available at 42nd Law Commission Report
Cavadino, Michael and Dignan, James, The Penal System: An Introduction, 2nd
ed., 1997, Sage Publications, London.

17. 17
CONCLUSION
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 desirablilty 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

18. 18
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.