Imagine I buy and sell coffee products, and have done so legally for many years. However, the FDA decides that coffee is a carcinogen, an addictive drug, and extremely dangerous, and consequently places it on Schedule I drug, along with Heroin.

I continue to buy and sell coffee entirely unaware of the change in law. Then the feds come over, bust down my door and I am facing a charge of dealing schedule 1 drugs, and life imprisonment.

What is the legal situation here? Plainly I had no mens rea, I was entirely unaware of the change in the law, and reasonably would have expected my previously legal activity to continue to be legal.

However, I also know the epithet that ignorance of the law is no defense. So what would my legal situation be here?

  • ‘Dealing schedule 1 drugs’ is not a specific crime - whether or not you had mens rea will depend on the explicit crime charged with. There are sometimes very similar charges that dramatically change the ability to use a mistake of fact or mens rea argument (think murder vs. involuntary manslaughter)
    – Prince M
    Jun 27, 2018 at 16:43

3 Answers 3


In law, there is a distinction between mistake of fact and mistake of law. If the law prohibits X, and you think you're doing Y, that's a mistake of fact. If the law prohibits X, and you know you're doing X, but you think the law prohibits Y, that's a mistake of law. Mistake of fact is generally a defense (although that principle is being eroded), but mistake of law is not. In your hypothetical, you clearly had the intent to sell coffee, so you had mens rea. Mens rea refers to the intent to perform the act that is illegal, not the intent to break the law. If you intend to follow the law, but intentionally perform an act that is against the law, it is the latter that forms mens rea; mens rea refers to your intent regarding the act you are performing, not your intent regarding the law.


You're going to jail

21 U.S. Code § 841:

(a) Unlawful acts Except as authorized by this subchapter, it shall be unlawful for any person knowingly or intentionally—

(1) to manufacture, distribute, or dispense, or possess with intent to manufacture, distribute, or dispense, a controlled substance; or

Do you see where they talk about mens rea in there? Its in the word "knowingly".

Since the adoption of the model penal code in the 1950s the common law concept of mens rea has been codified. Specifically, knowingly is:

A person acts knowingly with respect to a material element of an offense when:

(i) if the element involves the nature of his conduct or the attendant circumstances, he is aware that his conduct is of that nature or that such circumstances exist; and

(ii) if the element involves a result of his conduct, he is aware that it is practically certain that his conduct will cause such a result.

Assuming the law making coffee a prohibited substance has been properly promulgated then your ignorance of it is voluntary ignorance - you could have learned of it and should have learned of it and therefore you "knowingly" chose to distribute coffee in violation of the law.

There is an exception in federal tax law - where the law uses the term "willfully", SCOTUS has held that this carves out an exception to the traditional rule that ignorance of law cannot be excused.

  • 1
    Ignorance of the law is definitely not a defence - but it may be a plea in mitigation. If the OP genuinely the had not heard about the change in the law, they might avoid jail. Apr 5, 2018 at 16:15
  • 1
    @MartinBonner except ... banning coffee would be so newsworthy that no one would believe you hadn’t heard of it.
    – Dale M
    Apr 5, 2018 at 19:17
  • I was going with the (implausible) supposition in the question that the vendor hadn't heard of it. Apr 6, 2018 at 6:47
  • @MartinBonnersupportsMonica agree, it may change the charges from intentional or willfully to negligence, which will impact sentencing.
    – Tom
    Dec 4, 2023 at 14:57

Legal principle:

Ignorantia juris non excusat

(ignorance of the law is not an excuse - more details here)

Your ignorance of this change in law would not protect you from being charged and convicted. Assuming that the law was passed and published properly, after which the legal assumption is that everyone knows what the law is, because you could've read it.

In practical terms, this is one of the functions of business organisations like your local coffee trade chamber or local business owner group. They will monitor the legislative for such changes and inform their members.

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