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Actus non facit reum nisi mens sit rea


This latin maxim means that, an act itself does not constitute guilt unless done with a guilty intent.

The act does not make a man guilty unless his mind was so. It emphasis on INTENT + ACT = CRIME. For an act to be criminal, it must be committed with a guilty mind.

The maxim is an important concept of the Indian penal code with respect to elements of the crime.


The two basic components of criminal law is Actus Reus and Mens Rea. Actus Reus is the wrongful act committed and Mens Rea is the state of mind behind such acts.

The Latin maxim Actus Non Facit Reum Nisi Mens Sit Rea is derived from Mens Rea. Actus Non Facit Reum Nisi Mens Sit Rea further explains as to how Mens Rea is applicable in criminal law. It states that a person is guilty of a criminal act only if such acts are accompanied by a criminal intention. This maxim is used to determine whether an act committed is criminal in nature or not. Several penal actions are required for crimes committed with specific intend and not for unanticipated or unintentional acts. However no breach of law can be left unpunished.

Thus this maxim is established to differentiate between intentional and unintentional criminal act so that the quantum of punishment can be decided accordingly.


When a person is attacked by another person with an intention to cause grievous hurt or injury then it is a crime. But when the person who was attacked causes injury to the other person in private defence then it is an unintentional act.

In the first scenario guilty mind was present but in the second case no intention of causing harm was there. The second act is categorised as self defence and is dealt under section 96 to 106 of the Indian Penal Code. In the first act the person is guilty of criminal act.

English Law

This maxim, has reference chiefly to criminal proceedings, and in such cases it is the rule that the act and intent must both concur to constitute a crime ; yet, the law will sometimes imply the intent from the act, under the maxim, Acta exteriora indicant interiora secreta.“ Those cases in which the law will imply the, intent from the act are where an act is done in abuse of lawful authority ; as where a man having by law authority, in the exercise of some public duty, to enter a railway station or other public building, and, being therein, commits, a felony, it will be presumed that he entered the premises with a felonious intent. So, of a sheriff or other public officer acting in excess of his authority, he will, in respect of such excess, and upon the same principle, be deemed a trespasser ab initio. So, in cases where the act done is positively forbidden by express enactment to be done, the intention to do it will be implied.

The crime of murder furnishes at once an instance in illustration of both the maxims under consideration ; for though, on the one hand, the act of killing does not of itself constitute the guilt, unless done with a guilty intent, yet a guilty intent will in such a case be presumed.

The question of malicious intent forms, also, an important feature in the actions of libel and slander. It is said, “the greater the truth the greater the libel;” meaning that the more true the matter published is, the more readily it will be believed, and in consequence, the more defamatory it will be; and that, therefore, the mere unauthorized publication of a truth reflecting upon a man's character is a libel yet, the written or printed publication of the libelous matter is always attributed to a malicious intent on the part of some parson or other. There is a difference between libel and slander in this respect. Generally speaking, libel is a written or printed publication of defamatory matter; and the fact of writing or printing defamatory matter is of itself a sufficient indication of intention on the part of the writer or printer that it shall go to the world for as much as it is worth; and in that case the malicious intention in publishing must be taken to be equal in substance to the libel; and malicious intention in such case is not an essential ingredient to the support of the action. In slander, however, the words used are frequently the mere outbursts of a hasty temper, and though slanderous and actionable if spoken with a malicious intent, yet, without the malicious intent, in the absence of special damage, they are not actionable, unless indeed the words used would lead the bystanders to infer that the party slandered had been guilty of some criminal offence, sed quare, without special damage; in which case, as in that of libel, the intention must be implied.

In an action for libel against a railway company, it was held that the action would lie if malice in law might be inferred from the publication of the libelous matter. It has been also held that to convict of larceny there must be not only an intention to commit the offence, but a means also of carrying it into effect. Therefore, where a man put his hand into the pocket of another with intent to steal, it was held that he could not be convicted of an attempt to steal unless there appeared to have been some- thing in the pocket which he might have stolen.

Insanity and Mens rea

Legal insanity is different from Medical insanity. Section 84 of Indian Penal Code provides,

“Nothing is an offence which is done by one, who at the time of doing it, by reason of unsoundness of mind is incapable of understanding the nature of the act or that it was either wrong of contrary to law.”

So provision of Section 84 embodies the fundamental maxim of criminal law “actus non facit reum nisi mens sit rea” (an act does not constitute guilt unless done with guilty intention). To attract the provision of Section 84, it must be established that, when the act was committed, the accused was labouring under such a defect of reason as not to know the nature and quality of the act he was doing. It must be born in mind that there is a clear distinction between legal insanity and medical insanity. Courts are concerned with the legal insanity and not with the medical view of the question. A man may be suffering some form of insanity in the sense in which the term is used by medical men but may not be suffering from unsoundness of mind as described in Section 84. If the facts of a case showed that the accused knew that he had done something wrong, though he might be insane from the medical point of view, he could not be exonerated under section 84 IPC.

Supporting Decisions

In Gour Chandra v. State of Orissa1) it was observed that ”it is only legal insanity that furnishes ground for exemption from criminal liability. There can be no legal insanity unless the cognitive faculty of the accused is, as a result of unsoundness of mind, completely impaired. In order to constitute legal insanity the unsoundness of mind must be such as to make offender incapable of knowing the nature of the act or that he is doing an act contrary to law.“

Similarly in Sankaran v. The State2) the Kerala High Court observed that Insanity as contemplated by Section 84 IPC is disorder of conduct i.e. the process of adjusting the self to circumstances is deranged, Insanity is an incapacity to know the nature of act or to know that the act is wrong or contrary to law. Section 84 contemplates legal insanity and not medical insanity

Important Points

  • Actus Non Facit Reum Nisi Mens Sit Rea explains that for any act to be illegal in nature it must be done with a guilty mind.
  • Thus to convict the accused, it must be proved that the criminal act was carried out with a criminal intend. Not only is the act of the accused important but the intention of the accused to do the specific act is equally important to prove the guilt of the accused.
  • Thus it can be concluded that mere commission of a criminal act or breach of law is not sufficient to constitute a crime. It should be combined with the presence of wrongful intent.
  • Further the mens rea is important to understand the severity of the crime committed. The essential ingredient is the blameworthy condition of the mind. Its absence can negate the liability.
  • However the statement without a guilty mind there is no crime is subjected to certain exceptions such as strict liability. Under strict liability, it is not necessary to show that a defendant possessed the relevant mens rea for the act committed.
  • This maxim can find its importance under section 14 of the Indian Evidence Act, 1872. It states that facts which indicate state of mind or intention are relevant facts in issue.

Case Law

In R. Balakrishna Pillai v/s State Of Kerala it was observed that “Criminal guilt would attach to a man for violations of criminal law. However, the rule is not absolute and is subject to limitations indicated in the Latin maxim, actus non facit reum, nisi mens sit rea. It signifies that there can be no crime without a guilty mind. To make a person criminally accountable, it must be proved that an act, which is forbidden by law, has been caused by his conduct, and that the conduct was accompanied by a legally blameworthy attitude of mind. Thus, there are two components of every crime, a physical element and a mental element, usually called actus reus and mens rea respectively.”

1990 (1) Crimes 168
1994(2) Recent Criminal Reports 446

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