Does “Ignorance of the Law Excuses No One” Make Sense When No One Knows How Many Laws Exist?

The WSJ has a lengthy piece about the proliferation of federal criminal laws,  and tells the story of a number of people who unknowingly violated obscure federal criminal statutes–many of which lack a mens rea requirement–including history buff Eddie Leroy Anderson, who violated the 1979 Archaeological Resources Protection Act by removing arrowheads from federal land without a permit.

Should society hold people accountable for violating laws–without any mens rea–that few if any experts know exist? Judge Posner addressed just this point in his dissent in United States v. Wilson:

We want people to familiarize themselves with the laws bearing on their activities. But a reasonable opportunity doesn’t mean being able to go to the local law library and read Title 18. It would be preposterous to suppose that someone from Wilson’s milieu is able to take advantage of such an opportunity. If none of the conditions that make it reasonable to dispense with proof of knowledge of the law is present, then to intone “ignorance of the law is no defense” is to condone a violation of fundamental principles for the sake of a modest economy in the administration of criminal justice.

Even if Anderson were to go to the local law library, and read through the entirety of Title 18, it’s unlikely he would be able to learn all of the federal laws. As the WSJ piece points out, several attempts at cataloguing all federal crimes, including violations of regulations that carry criminal penalties, by the Department of Justice, the American Bar Association, and others have failed.

Counting them is impossible. The Justice Department spent two years trying in the 1980s, but produced only an estimate: 3,000 federal criminal offenses.

The American Bar Association tried in the late 1990s, but concluded only that the number was likely much higher than 3,000. The ABA’s report said “the amount of individual citizen behavior now potentially subject to federal criminal control has increased in astonishing proportions in the last few decades.”  . . .  Today, there are an estimated 4,500 crimes in federal statutes, according to a 2008 study by retired Louisiana State University law professor John Baker.

So if the smartest legal minds are unable to list all of the federal crimes, how can we hold people like Anderson culpable for violation of essentially unknown federal laws that lack any intent requirement? Is Posner right to say we are condoning a violation of a fundamental principle of justice for the sake of a “modest economy in the administration of criminal justice”? Is ignorance of the law no longer a valid excuse? If so, what would the remedy be?

Cross-Posted at

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22 Responses

  1. Patrick says:

    I’m sympathetic to this argument, but “modest economy” seems like an understatement. How would you go about proving the “knowledge of the law” element if you had to do so?

  2. Josh Blackman says:

    From the article:

    A study last year by the Heritage Foundation and the National Association of Criminal Defense Lawyers analyzed scores of proposed and enacted new laws for nonviolent crimes in the 109th Congress of 2005 and 2006. It found of the 36 new crimes created, a quarter had no mens rea requirement and nearly 40% more had only a “weak” one.

    I think these laws have to be passed without a mens rea requirement; otherwise, they would be totally ineffectual, because odds are no one would ever have any intent to violate them (no one would even know the law exists!).

  3. Patrick says:

    I mean, just because there’s no mens rea requirement written into the law doesn’t meant there’s no mens rea requirement for a violation. I’m not a criminal lawyer, but if IIRC it defaults to recklessness. Even criminal statutes that have a “strong” mens rea requirement (i.e. purpose/intent) are criminal without regard to your knowledge of the law. Just like with every law, it’s your intent/recklessness/knowledge with respect to the thing you’re doing, not its illegality.

  4. Josh Blackman says:

    There is also the issue of prosecutorial discretion. Even if these laws exist, a US Attorney still must seek the indictment.

  5. Brett Bellmore says:

    “Ignorance of the law is no excuse.” was not based on the notion that people could read the entire legal code, and thus could be held responsible for not having done so. It was based on the assumption that most laws were malum in se, that a person of normal moral sense wouldn’t need to read the law to know a particular violation was something they shouldn’t be doing, because the law prohibited moral wrongs.

    It’s not so much the proliferation of laws that makes the concept nonsensical, as the proliferation of malum prohibitum laws, of laws outlawing conduct a person of normal moral sense wouldn’t realize were wrong to commit, because the only thing wrong with doing them was that somebody had passed a law.

    Perhaps the remedy is a government that is more modest about what it’s entitled to enact laws about?

  6. Shag from Brookline says:

    Brett’s questionl:

    “Perhaps the remedy is a government that is more modest about what it’s entitled to enact laws about?”

    sounds like a libertarian heaven, e.g., the Roaring Twenties. Query: what might be malum in se to libertarians?

  7. A.J. Sutter says:

    1. Some ignorant questions, apropos of the Posner quote that’s bolded in the main post:
    (i) “If none of the conditions that make it reasonable to dispense with proof of knowledge of the law is present”: what are those conditions (other than where someone lacks capacity to distinguish between right and wrong, generally)?
    (ii) “…is to condone a violation of fundamental principles”: to which fundamental principles does he refer?

    2. As for over-zealous criminalization of some actions, isn’t the Constitution (which I recall as setting forth some “fundamental principles”) supposed to be our safeguard against that?

    3. (i) Given the detailed nature of most criminal statutes, it would be all too easy to create reasonable doubt that someone “knew” the law, wouldn’t it?
    (ii) So any accommodation to the knowledge issue should include an adjustment of the burden of proof. Do people really want to mess with that?
    (iii) If people do mess with the knowledge quantum and/or the b/p, is there a Constitutionally-based argument for why such adjustments should be prospective only? Wouldn’t it be a nightmare far beyond a “small economy” to make this retroactive?

    4. BTW there’s an analogous problem brewing in public international law, with regard to treaties. Currently there are tens of thousands of treaties — no one knows to what extent they conflict with each other.

  8. TJ says:

    I agree that there is a serious problem of having so many criminal laws that nobody knows what they are. But having a “mens rea” requirement is not the answer, at least if you mean by “mens rea” what it is normally understood to mean. Murder has a mens rea requirement, but there was and is no requirement that a person had to have read the statute to have mens rea. All you need to do is intend the act and the factual result (i.e. the person dies); it is elementary criminal law that mens rea does not encompass a requirement to be aware that the act is illegal.

  9. Josh Blackman says:


    To your second question, I agree the Constitution provides certain safeguards, though I am not just talking about due process or various criminal procedure elements. The Constitution only mentions 3 crimes by name (treason, piracy and counterfeiting). Perhaps, as we saw in Bond, doctrines of federalism, and enumerated powers can be used to protect individual liberty from federal prosecution by limiting the extent of federal crimes.

    This issue is especially important with respect to your 4th question about the countless treaties in existence.

  10. Brett Bellmore says:

    Theft, assault, breach of contract… Essentially, things that harm other people, not one’s self, contrary to their will.

  11. Toothiron says:

    Sounds to me like there should be a jury instruction: “[I]gnorance of the law is not an excuse to violating the law, unless, by a preponderance of the evidence, a reasonable person would not realize his or her conduct violated the law in question.”

  12. Shag from Brookline says:

    In the closing paragraph of his post, Josh asks:

    “Is ignorance of the law no longer a valid excuse?”

    suggesting that ignorance of the law has been a valid excuse. But this does not seem to be the case.

  13. Logan says:

    As an avid backpacker/rock climber/user of federal lands for outdoor activities, I can assure you that the government had many a notice indicating what he was doing was illegal. Any trail map would mention it not to mention the plethora of signs posted in parking lots and bulletin boards.

  14. A.J. Sutter says:

    I should have known better: read the case. The original post blends two issues: ignorance of the law and mens rea. Judge Posner’s dissent actually rests on the former, not the latter. See ¶¶ 32-34 of the majority opinion, where the distinction is drawn between the two issues; the majority cite Bryan v. United States, — U.S. —-, 118 S.Ct. 1939, 1946-47, 141 L.Ed.2d 197 (1998) as an example of an exception to the general rule about ignorance of the law, but hold it doesn’t apply here. The Bryan case doesn’t turn on the mens rea issue at all; it carves out an exception to the ignorance rule in the case of “highly technical statutes that present[ ] the danger of ensnaring individuals engaged in apparently innocent conduct,” slip op. at 10, 118 S.Ct. at 1947 (citing some tax cases and a case under a currency structuring statute; moreover, the reasoning for the exception seems to have been based on questions of Congressional intent, rather than on express Constitutional issues). Then see ¶ 71 of Judge Posner’s opinion which argues that the Wilson case does fall within the Bryan criteria. Posner himself distinguishes the mens rea issue in ¶ 72. BTW, the offense in Wilson’s case had to do with his possession of a firearm in interstate commerce while there was a protective order against him in connection with a domestic dispute.

  15. Shag from Brookline says:

    After reading A.J.’s comment (#!4), perhaps a goal of this post is an attack on positivism (and thus indirectly on Justice Holmes).

  16. Joe says:

    Following up on comment 13, the article notes:

    “Wendy Olson, the U.S. Attorney for Idaho, said the men were on an archeological site that was 13,000 years old. “Folks do need to pay attention to where they are,” she said.”

    They “pleaded guilty to a misdemeanor and got a year’s probation and a $1,500 penalty each.” These stories tend to have nuances like this, including how “a retired logger, a former science teacher” who goes on a “favorite campground” is more appropriately under an obligation to know the rules than some random visitor.

  17. david in louisville says:

    At a more pedestrian level, it might not be a bad idea to start out with the understanding that the rule against using ignorance as a defense is similar in function to the presumption of legitimacy or Justice Scalia’s dictum that courts presume jurors follow instructions because it is necessary to believe it is true. The criminal law is littered with relics like these principles. They persist because they are useful to the prompt dispatch of the main business of the courts, placing the judicial seal of approval on administrative determinations of criminality made by prosecutors and grand juries.

  18. frankcross says:

    If ignorance of the law were to be an excuse, that would give people a pretty strong incentive to be ignorant of the law.

  19. quiel says:

    The extremely unwieldy and almost impossible juridical process of establishing statutory ignorance of any legal personality makes it vital and very necessary for a man made judicial system to use a PRESUMPTION that a legal personality is at least AWARE and has a FAIR UNDERSTANDING of a particular law or statute AFTER due public notice has been made about the statutory provision. It is extremely difficult to prove ignorance under normal circumstances and it would be very easy for anybody to escape from the law simply because he claimed ignorance from it. HOW CAN YOU PROVE IGNORANCE IF YOU KNOW YOU LIVE IN A SOCIETY WHERE A SET OF PUBLIC NORMS AND STANDARDS DO EXIST? EVEN IF YOU DO NOT KNOW A SPECIFIC LAW, YOU DO KNOW THAT THERE ARE LAWS TO BE FOLLOWED AT LEAST. It will be a GRAVE INJUSTICE for all law abiding citizen of ANY civilized state to include ignorance of the law in the jurisprudence of civil and criminal innocence. It therefore makes it VERY NECESSARY for a LEGAL PRESUMPTION to be included in legal jurisprudence to PRESUMPTIBLY ensure equity and justice to any and all citizen of a state. Inherent limitations and weaknesses in any judicial system may exist relative to bureaucracy but it MUST NOT be a reason enough to compromise judicial equity with an extremely difficult to prove and highly prejudicial IGNORANCE OF THE LAW.

    Ignorance of the law is primarily a matter of conscience which is very difficult to establish in court under ordinary circumstances. NOT EVEN THE BEST HARVARD EDUCATED JUDGE CAN ASCERTAIN WITH ABSOLUTE CERTAINTY THE ESSENCE OF A PARTICULAR HUMAN CONSCIENCE WHICH IN THIS PARTICULAR CASE THE IGNORANCE OF LAW. In a capitalist society, which gives democracy its framework, necessitates that power emanates from the people AND PEOPLE ALONE which PRECLUDES a much more POWERFUL and MOST ESSENTIAL type of power which is the DIVINE POWER or power from God. The fact of which is empirically evident on most fundamental laws of almost all democratic state which is the SEPARATION OF THE CHURCH AND THE STATE. The reason for the concept of SEPARATION OF CHURCH AND STATE is the basic human right of FREEDOM OF RELIGION which comes from yet another basic concept which is FREEWILL. It is necessary to separate the power of the church and state because of the INTENT of the law to protect the basic human right of FREEWILL and also to avoid BIASES and DISCRIMINATION within the state. The spirit of the law here has a noble intent which is to promote equity and to protect and secure basic human rights.

    IN THE FINAL ANALYSIS THEREFORE it is this FREEWILL of every human being that necessitates the legal presumption of IGNORANCE OF THE LAW EXUSES NO ONE. The inevitable problem area with this legal framework however is the DIVERSITY OF INDIVIDUAL INTERESTS and CIRCUMSTANCES THAT DIRECTLY MODIFY A PARTICULAR FREEWILL. It is ONLY the QUALITY OF ACTUAL CONSCIENCE that directly modifies freewill and this EXTREMELY SUBTLE AREA of QUALITY OF ACTUAL CONSCIENCE that is extremely difficult to establish in court which necessitates the legal provision “ignorance the law excuses no one from compliance therewith”.

    Democracy uses legal standards set by its sovereign people ALONE which precludes DIVINE POWER due to the intent of the human law NOT TO VIOLATE FREEDOM OF RELIGION. This stems from the fact that there exists an almost infinite number of distinct religious views and standards which DIRECTLY MODIFIES the quality of individual human conscience. WHICH DIVINE POWER WILL THEY USE IF EVER? THE POWER OF THE GOD OF CATHOLICS? THE GOD OF THE IGLESIA NI MANALOS? ETC.

    But for me personally, there is only one source of divine power which is THE GOD OF THE BIBLE ALONE. That God unfortunately does not belong to catholics nor to the iglesia ni cristo of manalo nor with any other religious groups claiming direct divine intervention. It is my belief that this God of the Bible is not known by almost all religion dominating my country and all country if I may. HAD ONLY THE DIVINE POWER OF THIS GOD OF THE BIBLE INCLUDED IN ANY LEGAL FRAMEWORK, SUCH LEGAL PRESUMPTION “IGNORANCE OF THE LAW EXCUSES NO ONE FROM COMPLIANCE HEREWITH” WOULD BECOME ILLOGICAL FOR IT IS DECLARED BY THIS GOD HIMSELF IN THE BIBLE THAT;

    “The heart is deceitful above all things, and desperately wicked: who can know it?

    I the LORD search the heart, I try the reins, even to give every man according to his ways, and according to the fruit of his doings.”

    – Jeremiah 17:9-10


  20. Shag from Brookline says:

    Perhaps we need a wall to separate ignorance of the law and ignorance of religion and separately weigh excuse defenses.

  21. quiel says:

    @shag Why do we need a separate wall for that? What’s the logic? Perhaps you can expound more about separating ignorance of the law from ignorance of religion.

  22. Shag from Brookline says:

    My comment was a bit of tongue in cheek regarding comment 19. The Constitution does not provide a specific provision structuring a wall of separation between church and state although the wall has served well over the years. Comment 19 challenges, in effect, positivism. The law, civil and criminal, under the Constitution has not been based upon natural law, moral law or religious law, although some elements of such may be reflected with enactment of positive law. The concept of ignorance of the law generally not being an excuse developed because without it positive law could become a negative. (I am aware there are constitutional limitations even on positive law.)

    To me, ignorance of religion comes into play in at least two ways. First, many are not that knowledgable of various religions. Religions differ significantly. But under our Constitution, the Constitution, laws enacted pursuant thereto, etc, are the supreme law of the land, not any of the numerous religions. Second, some religions themselves may be ignorant, especially a religion of the “other.” The Bible in its various versions, including the old and new Testaments, cannot be taken as truly descriptive of events that are claimed to have occurred. (Read Mark Twain.) And interpretation of the Bible as well as holy books of other religions is in the eye of the faithful beholder. While our Constitution may not be clear on certain issues (e.g., Section 4 of the 14th Amendment), it has governed fairly well.

    Comment 19 seems to take the position that God trumps the Constitution’s supremacy clause. Two walls may provide more protection than Jefferson’s wall.