Ignorantia Juris Non Excusat


The maxim Ignorantia Juris Non Excusat means ignorance of the law is no excuse. “Ignorance of the law is not an excuse,” says an ancient legal nostrum. This maxim is originated from ancient Roman law. The reason is quite simple, if ignorance can excuse any crime, then ignorance could excuse all crimes. Instead of imposing on the legal system an obligation to prove the defendant’s knowledge of the law, with the defendant’s incentive going in the opposite direction, towards ignorance of the law the legal system assigns no obligation to itself. Whereupon the defendants find that they have a tremendous incentive to know what the law is and to behave accordingly. We can put the meaning of the word “the law” as the regime that orders human activities and relationships through the systematic application of the force of politically organized society or through social pressure in that society. In the legal system, all people are expected to respect and obey the law. With some exceptions, almost all of our conduct is regulated by law. We have various types of law such as civil, criminal, personal, family, fiscal, public and private international law, etc. But it is well known that ignorance of any of these laws cannot constitute an alibi.

Origin of Ignorantia Juris Non Excusat

The earliest use of the maxim in English law can be traced in Blackstone’s Commentaries, where it’s stated that: “often a mistake in point of law which every person of discretion not only may, but is bound and presumed to know, is in criminal cases no sort of defence. Ignorantia juris, quod quisque teneture scire, neminem excusat is as well the maxim of our own law as it was of the Roman”. Thus, it can be seen that the traces the origin of the maxim to Roman law which states that every man is obliged or presupposed to know the law. However, it explains that this is not a defence in criminal cases. From then on, English courts consistently applied this maxim as a rule of law, thus firmly establishing it in English law.

Sine Qua Non

Let us first analyse what is the sine qua non, that should be for this maxim to be valid. The sine qua non would be the same as in a case where one writes a letter to another with the intention that the letter is read and the desired message is understood. Therefore, what is required is that the message is delivered first to the addressee and then that the addressee is able to understand (that is, he must know how to read and understand what is written together with the legislative intent). Therefore, the sine qua non must be “Enactment” and “Knowledge”.

“Knowledge” refers to the ability to know. In a given context, it can only be decided whether a law is knowable or not, if that law:

  1. Ability to read
  2. Understanding the context

This “ability” aspect of the law provides the “Logistics” requirement (from the legislator to the audience in question). This means that each and every one of the laws must be very well publicized or promulgated so that they are available for the intended audience. Now, the question arises of understanding the law. The acts, rules, circulars, notifications, etc. which are approved by state governments are written in regional languages ​​and sometimes in English as well. Whereas, the core laws are written in English and Hindi (being the official language). The possibility that people who don’t even understand Hindi cannot be ruled out. Also, even if one is able to read, about “Vagueness in the law”.

This is another aspect that must be taken into consideration while discussing the ability to understand a law. A person who commits a crime must know the law, for which the law must be clear and not vague. In addition, even a lawyer before arguing or a judge before drafting a ruling refers to the Bare Acts and comments to check them. That means, even capable people must take a second look at the laws to be sure. Therefore, the question is, can one be completely updated from a particular law.

The “knowledge” of the law is necessary to determine if one was negligent in knowing the law or could not have the opportunity to know it at all. This also leads to generating a requirement to differentiate between the “mistake of law”, and “Ignorance of Law” is more or less the same. The mistake of the law implies that the doer has knowledge of the law, but that knowledge leads to erroneous conclusions. Whereas, ignorance of the law implies a total lack of knowledge. However, the conclusion in each case is the same, that is, committing an act that is illegal. Different commentators have different points of view when considering whether ignorance and mistake of law are considered one and the same or not.

Furthermore, will ignorance of the law amount to Mens rea? Mens rea means having a guilty mind or a guilty mental state, in which the perpetrator of the act is aware of the illegality and is prohibited by law. Whereas, in the scenario where the doer ignores the law, he lacks the knowledge of the law, as well as the absence of the mental state. Therefore, ignorance of the law cannot lead to Mens rea.

The Rationale Behind the Maxim “Ignorantia Juris Non Excusat”

The principle behind the meaning of “Ignorantia Juris Non Excusat” is based on the presumption that everyone, rather subject to obligations, knows the law. The ignorance of these, forced to know, things, therefore, does not excuse anyone. Scholars express it as a mere legal fiction, which has been created out of necessity for convenience. Therefore, a mistake of law, without taking into account the logic that supports it, even in good faith, does not operate as a factor of acquittal.

If the maxim is relaxed, then any defendant can claim that he had no knowledge of the law on his part. Therefore, it will be almost impossible for the prosecution to prove the same. Hence, out of necessity, it is not advisable to dismantle the tool, which is necessary for the effective administration of justice. Criminal law is based on certain moral principles and, therefore, when someone breaks the law, he or she knows very well that he or she is breaking the rule of law, although he or she is ignorant of some of the provisions of the law. Obviously, this presumption is not based on fundamental realities. In fact, the sheer volume of statutory laws makes it impossible for even skilled attorneys to be so familiar with all the provisions. However, the “legal fiction” is justified, Ignorantia Juris non Excusat, by the public interest. Allowing for error of the law can also lead to fostering ignorance of the law.

Statutory Provisions on Ignorantia Juris Non Excusat

The Indian Penal Code, 1860

A plain reading of Section 76 and Section 79 of the Indian Penal Code of 1860, with special attention to the words “who by an error of fact and not by an mistake of law believes in good faith” that appears in the same, shows us that the protection of the sections applies only to the error of fact and not to the mistake of law. This is based on the common law maxim: Ignorantia Facti doth Excusat, Ignorantia Juris non Excusat, ignorance of the facts is an excuse, but ignorance of the law is not.


A, a foreigner, kills B in a duel in India. He believes that bereavement is legal in India. “A” is guilty of murder. The act committed by “A” was a specific act that for the first time was classified as a crime by law. “A” proves that at the time the statute was passed, he was at sea and could not have known. This defence is not allowed, as ignorance of the law is no excuse.

In Emperor v. Nanak Chand it was held that “where a statute provides that certain knowledge of the law by the accused is an essential element of the offence, a good faith mistake of law may be a good defence to a charge of an offence”.

Criticism of the Maxim “Ignorantia Juris Non Excusat”

In India, the majority of the population is illiterate and therefore this presumption of knowledge of the law seems not only illogical but also ridiculous and unfair. Legal knowledge is very poor even among educated and literate people. Even professionals, lawyers, judges, and law professors, do not claim or know all the laws.

Noting the implications of the strict application of the principle that “mistake of law is no excuse” and the relaxations made in other jurisdictions, Justice RL Narasimham suggested that mistake should be a defence where the mistake of law relates to a provision of a rule, statute, regulation or notice issued under an Act of the Legislature. The defendant’s mistake is such that it could not have been avoided with due diligence at the time.

Is the Rule Rigid And Without Exceptions?

We have already established that the maxim has its origins in ancient Roman law. At that time, the number of laws was very small and therefore easy to remember and understand. The number of laws or rules was very small and could even be counted. Therefore, the rule may be justified in such a situation. But look at the current situation. There are thousands of laws enacted by the Parliament and various states.

There are thousands of rules issued by the executive, i.e. the government. Even the Supreme Court and various higher courts have developed rules of procedure and practice, etc. There is customary law and personal law like Muslim law etc. There are hundreds and thousands of binding notices and circulars for various parties. Most importantly, we have a number of laws dictated by judges and derived from various court decisions which, as we know, are constantly changing. Even the government is not aware of the number of laws that are in force and in effect in this country.

Some of the laws, such as the Companies Act 1956, comprise 658 sections, and in addition to this vast army of sections, there are a number of rules, regulations, notices, circulars etc. It is humanly impossible to memorise, let alone understand, this army of laws piled up before the eyes of the citizens. It is better not to say anything about the illiterate or those who understand neither English nor Hindi (laws in India are written in English and Hindi with translations into vernacular languages).

Position in England

English judges long ago set aside the maxim when the situation demanded it. Scrutton L.J. once said, “It is impossible to know all the statutory law, and scarcely possible to know all the common law”. It was also the accepted position that the rule “ignorance of the law does not excuse” cannot be invoked to escape the consequences of criminal law, but the law can take cognisance of the existence of doubtful questions of law about which a person may be ignorant. According to Lord Westbury in Cooper v. Phibbs, the word “jus” in the maxim ignorantia juris baud excusat is used in the sense of “general law, the law of the land”, not in the sense of “a private right”. The true meaning of this maxim is that parties cannot absolve themselves from liability for all the civil or criminal consequences of their actions by pleading ignorance of the law; however, it is not presumed that the parties know all the legal consequences of their actions, especially when difficult questions of law or the practice of the court are involved.

Position in United States of America

The status of the maxim in the USA is no different from that in England or India. Reference should be made to the famous Lambert v. California, a case decided by the Supreme Court of America, which held: “If this ordinance is applied to a person who has no actual knowledge of his duty to register, and unless it is shown that such knowledge is probable, it violates the Due Process Clause of the Fourteenth Amendment.” Because of the multiplicity of statutes and regulations, it is sometimes difficult for the average citizen to know and understand the extent of the duties and obligations imposed by the tax laws. Accordingly, Congress has weakened the impact of the common law presumption by making specific intent to violate the law an element of the offence for certain federal tax offences. Thus, nearly 60 years ago, the Court interpreted the term “intentional” as used in federal criminal tax statutes to be an exception to the traditional rule. This special treatment of tax crimes is largely due to the complexity of the tax laws.  In United States v. Murdock, 290 U.S. 389 (1933), the Court recognised that: “Congress did not intend that a person should become a criminal by reason of a bona fide misunderstanding as to his tax liability, his duty to file a return, or the sufficiency of the records he kept, by his mere failure to meet the required standard of conduct.”

Position in India

Let us now look at the situation in India. India, which has been under British rule for over 200 years, has adopted British laws, albeit in a slightly modified form to suit Indian conditions and culture. Before the British takeover, Indian courts applied the personal laws of Hindus and Mohammedans in deciding legal disputes. If the litigants are Hindus, Hindu law applies, and if the litigants are Muslims, Islamic law applies. If one party is a Hindu and the other a Muslim, the law of the defendant applies. However, during British rule, Indian courts began to use English common law to resolve disputes, along with Hindu law and other purely Indian laws. By and large, however, English laws predominate. As far as the maxim is concerned, India too applied it, with exceptions. The maxim “Ignorantia Juris Non Excusat” was considered by the Supreme Court in Motilal Padampat Mills Ltd v. State of Uttar Pradesh (1979) 118 ITR 326(SC). The Supreme Court observed as follows:

“It must be remembered that there is no presumption that every person knows the law. It is often said that everyone is presumed to know the law, but that is not a correct statement: there is no such maxim known to the law.”

So, the Hon’ble Court has stated the law in very clear terms. There is no room for doubt. In a case decided by the Supreme Court, the judges openly admitted that they had never heard of the law allegedly violated by an illiterate man in a remote village. Therefore, the court acquitted the person charged with violating this law.  India has not applied the maxim bluntly.


The maxim Ignorantia Juris Non Excusat warns that people who violate the law will be punished regardless of whether they are aware of the law that prohibits or permits their activity, which may be considered a criminal offence. However, the principle behind this maxim is not that everyone should be aware of every legal provision. Rather, it is about the common good that enables the effective administration of justice.

In view of the above discussion, the author is of the view that the maxim must be applied only in appropriate cases and that the facts and circumstances of the case also justify its application. The above study on the status of the maxim in England, USA and India clearly shows that the courts are reluctant to accept the maxim bluntly. However, it cannot be completely abolished. I hold that in an appropriate case, if the circumstances clearly warrant it, the maxim Ignorantia Juris Non Excusat need not be applied and a person may be excused for his ignorance. It may not be permissible in criminal cases, but in other areas of law, it can only be applied if it is justified.

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Udita Prakash

I am Udita Prakash, pursuing a BBA LLB course from UPES, Dehradun.

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