McNaughten Case: Genesis of Law of Insanity

 McNaughten Case: Genesis of Law of Insanity

By: Robin Pandey                                                                                             Date: 08/03/2022

Entire law as to criminal liability of a person of unsound mind owes its genesis to the answers given in McNaughten Case (1843). In this case, the accused McNaughten murdered private secretary to the then prime minister. He was under an insane delusion that the Prime Minister had injured him and mistaking Private Secretary for the Prime Minister he shot and killed him. The accused pleaded insanity in his defence and the medical evidence produced showed that the prisoner was labouring under a morbid delusion which carried him away beyond the power of his own control. The Chief Justice was in the charge of the jury. The jury acquitted the prisoner on the ground of insanity.

The trial of McNaughten and his acquittal caused considerable sensation and was made the subject of debate in the House of Lords and as a result the House of Lords called on the 15 Judges to lay down the law on the subject of criminal responsibility in cases of alleged lunacy. Fourteen of the judges united in their responses. These responses are known as McNaughten Rules which form the basis of the modern law on insanity. The responses given by the judges in MCNaughten Case may be summed up in the following four propositions:

(1) Every man is presumed to be sane, and to possess a sufficient degree of reason to be responsible for his crimes, until the contrary be proved to the satisfaction of the Court. 

(2) To establish a defence on the ground of insanity, it must be clearly shown that, at the time of committing the act, the party accused was 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 this, that he did not know that what he was doing was wrong.

 (3) If the accused was conscious that the act was one which he ought not to do and if that act was at the same time contrary to the law of the land, he is punishable. Thus the test is the power of distinguishing between right and wrong, not, as was once supposed, in the abstract, but in regard to the particular act committed.

(4) Where a person under an insane delusion as to existing facts commits an offence in consequence thereof, the answer must depend on the nature of delusion; but making the assumption that 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. For example, if, under the influence of his delusions, he supposes another man to be in the act of attempting to take away his life, and he kills that man, as he supposes, in self-defence, he would be exempt from punishment. If his delusion was that the deceased had inflicted a serious injury to his character and fortune, and killed him in revenge for such supposed injury, he would be liable to punishment

Criticism of McNaughten Rules: In over a hundred years which have passed since the McNaughten rules were formulated they have been subjected to criticism from both medical and legal quarters. Some of these criticisms are as follows:

 (1) The rule concerning the burden of proof enunciated in the rules is anomalous. These rules were enunciated in a period when the common belief was that the presumption that every one intends the natural consequences of his act was a presumption of law. According to this view once the actus reus is proved, the burden of proving the absence of mens rea is laid upon the accused in all cases. In modern times, however, the old belief has yielded place to the new doctrine that the above presumption is not one of law but of fact. The consequence is that a man who contends that he did not intend the natural consequences of his act because of unsoundness of mind, he should not be placed in a worse position so far as the onus of proof is concerned that the other person who makes a defence on any other ground. In India, the Supreme Court approved the new doctrine.

(2) For a very long time an important word "wrong" occurs in McNaughten Rules had been interpreted to mean "morally wrong”, which was very debatable. In modern times, it has been laid down clearly that this term "wrong" means "legally wrong" and not "morally wrong" 

(3) McNaughten Rules are based on the outmoded theory that partial insanity is possible. It astounds many critics how an insane person can be sane at the same time, which seems contradiction in terms. Only medical science can answer this criticism. 

(4) McNaughten Rules do not provide for the derangement of the mind or insanity which affects emotions or wills. They laid down the law only on one aspect of insanity and may make no allowance for irresistible impulse and mental deficiency. Under Indian law, as also under English law, although irresistible impulse is not accepted as an excuse in a criminal prosecution, yet if it is proved before a Court of law, it does go to mitigate the punishment.