An infamous clause found occasionally in software licenses is:

The Software shall be used for Good, not Evil.

This clause has been discussed in many places, including Software Engineering Stack Exchange and Open Source Stack Exchange.

While a lot of people don't seem to like this clause, I wanted to step back and analyze the idea of "evil" from a purely legal perspective rather than the social milieu of the open source community.

To that end, is the term "evil" a proper term in law with a distinct meaning? One idea I had was to interpret it as a synonym of "unlawful" or maybe "criminal". The other idea is to understand it more in the sense of legal positivism, where socially-defined "good" and "evil" are distinguished from legally-defined "lawful" and "unlawful", and so a particular act might be "good" but "unlawful" or "evil" but "lawful".

Neither of these definitions seems satisfactory.

The problem I have with the first definition is that it adds unnecessary complexity to what should be more simply expressed as "This software is not to be used for any unlawful purpose." or "Committing any felony or gross misdemeanor with the software shall constitute a breach of the license agreement.". It also likely places someone who commits an unlawful act as minor as forgetting to add coins to a parking meter on the same level as a cackling comic book supervillain who gets off on bombing orphanages, which seems disingenuous.

The problem I have with the legal positivism definition is that it empowers a court to define social rules, which it is not designed to do. For example, some people (based on their beliefs) might characterize using scheduling software to manage abortion clinic appointments to be an "evil" use (and thus a breach of the license), while others might take the opposite perspective and claim that using the same scheduling software to plan anti-abortion protests or manage the shifts of law enforcement officers investigating suspected clandestine abortion clinics are "evil" usages forbidden by the license.

I'm interested in either an analysis of the meaning of "evil" in a general legal sense (in any jurisdiction in which the term might have been given a specific meaning or been interpreted by a court) or a sense restricted to software licenses, if such has ever been done.


As hinted at by respondents and commentators, I do see a distinction between acts that the vast majority of reasonable people would see as "clearly" evil such as ethnic cleansing, slavery, or rape and acts where the evil-ness or lack thereof is a valid point of debate, such as abortion, marketing habit-forming drugs, or not eating vegan. An answer might cover this. For example, is determination of whether a questionable act qualifies as evil a question of law for the judge or a question of fact for the trier of fact (e.g. jury)? Are the personal moral beliefs of the software licensor and/or licensee relevant? For example, if I have a personal moral belief (not shared by most of the members of my community) that eating at Burger King is evil because they buy from factory farms but I nonetheless use scheduling software with a "no evil" clause to schedule a lunch date at Burger King, am I in breach of the license? If the software's owner/licensor is a highly devout Catholic who considers any form of birth control to be pure evil but I (the licensee) disagree, is my act of using the software to facilitate an otherwise lawful condom purchase a breach?

I do recognize that none of the situations I described above are likely to land me inside a courtroom due to practical matters. That is why my question is about the nature and definition of "evil" for legal purposes rather than advice for any specific situation, license, or use. I know what "love" means, but what does "evil" mean?

  • 8
    Have you ever played Dungeons & Dragons, by any chance? You've touched on the fact that game, good/evil is a separate dichotomy from law/chaos (where "chaos" doesn't mean "unlawful" but more about unrestricted, individualistic, or "law-free"). A character can be Lawful Evil, Chaotic Good, etc. In fantasy literature, the dichotomy is usually called "order/chaos", and it tends to either equate chaos with evil, or to consider order and chaos as extremist, with "neutrality" as the good one. Commented Nov 30, 2022 at 17:50
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    @ShawnV.Wilson yes, in fact, I have, though mostly AD&D 2 rather than the newer stuff like 5e. I wasn't particularly referencing this though I can see how it might have influenced my thought processes. Commented Nov 30, 2022 at 19:22
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    I would argue that "evil" has the same precision of meaning as the word "bad". Whether the clause is sufficiently clear to be enforceable in circumstances where the author would want it enforced, is another question.
    – Steve
    Commented Dec 1, 2022 at 13:33
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    Since we're talking about D&D and alignment, we banned alignment questions at RPG because they ended up being too opinion based for Stack Exchange. Commented Dec 1, 2022 at 18:43
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    The "not for evil" clause is taken seriously enough that IBM obtained a waiver from the author of a software that was released with this license to be able to use it for evil. Presumably because IBM is often involved in developing military projects. Google also took it seriously enough that they developed compatible replacement libraries so that their projects can avoid using software with this license - not because Google wants to do evil (ha!) but because having restrictions on usage is incompatible with most open-source licenses.
    – slebetman
    Commented Dec 2, 2022 at 2:12

5 Answers 5


While not defined, in common law systems, there is a concept of Malum in se which can be translated to "Wrong or Evil in itself" and is used to describe criminal actions that are wrong because they are immoral as opposed to criminal actions that are wrong because they are prohibited (Malum Prohibitum).

As an example, Murder is considered Malum in se while driving on the wrong side of the road is Malum Prohibitum. Malum in se thus is a crime because the action is immoral.

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    "malus,-a,-um" isn't really evil as we use it now but the whole concept of... negativity: 1 bad, poor or bad quality 2 ugly 3 bad, evil, wicked, dishonest 4 malicious, harmful, dangerous 5 bad, hostile, negative, gloomy, ominous 6 incompetent, inept 7 sick 8 inappropriate 9 of humble social condition 10 unjustified
    – Trish
    Commented Dec 1, 2022 at 12:30
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    "malus,-i" on the other hand is just a wicked person. Mali in se could be "by itself a wicked person's [act]" while mallum in se could be "by itself dishonest/harmful/dangerous/hostile...", "by itself by wicked persons"or "(to the) wicked person in itself" - Accusative Singular doesn't make much sense there, but Genitive Plural does, as does the adjective variant.
    – Trish
    Commented Dec 1, 2022 at 12:36
  • "malum,-i" is bad, apple, suffering, mischief, harm, hurt and then it is best translated as "suffering in itself" or "bad in itself" - a lesser quality translation would use evil
    – Trish
    Commented Dec 1, 2022 at 12:40
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    @Trish The phrase in law has a specific meaning as described, in this case "Malum in se" is specifically a crime that is a crime because it is immorally wrong, which is one of the many definitions of Evil in the vernacular languages of Common Law. Whether or not it would mean the same to a native Latin speaker is a bit of a moot point.
    – hszmv
    Commented Dec 1, 2022 at 13:46
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    @ikegami The question has been modified since this answer was written. Legally speaking, "good" would be defined as "that which is not prohibited by law." For example, according to the answer, the law does not prohibit me from eating at Burger King, thus using software to achieve that goal will be legally good for the purposes of the contract. Additionally, in Contract law, when ambiguity exists, the interpretation most favorable to the party that did not draft the contract is used.
    – hszmv
    Commented Dec 5, 2022 at 18:37

Evil exists in the legal system

Evil is a perfectly cromulent word and, if this clause was ever litigated, the court would need it to determine its meaning and determine if the acts or omissions alleged met that definition or not.

The word itself has been used in numerous judgements.

For example, in Monis v The Queen [2013] HCA 4; 249 CLR 92; 87 ALJR 340; 295 ALR 259; 227 A Crim R 451 it was used in the following context:

  1. In other words and contrary to the appellants' submissions, it must be taken to mean more than insulting or annoying. Criminal sanctions are imposed. In context it must mean seriously offensive or grossly offensive, or repugnant in a moral sense. In this way its meaning would be in keeping with menacing: which means threatening to cause evil, harm or injury; and harassing -tormenting by repeated attacks. In context offensive means conduct which is more deserving of opprobrium than mere annoyance. It derives from the Latin and encompasses the notion of an attack and in this context a serious attack, one which is in keeping with its placement alongside the word menacing. In construing "offensive" in s.471.12, the CCA properly considered a range of matters including the context and subject matter.

More recently, in Alexander v Minister for Home Affairs & Anor [2022] HCA 19:

314 Whilst it must be accepted that it may be possible to enter innocently into a "declared" area, it is also possible to do so with evil intention. In 2014, Islamic State's reputation for extreme violence was notorious and it had become one of the world's deadliest and most active terrorist organisations.

In Australian jurisprudence the word appears to mean malicious acts intended to harm others.

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    It embiggens my spirit to see people using "Cromulent" in their answer.
    – hszmv
    Commented Dec 1, 2022 at 13:42
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    @hszmv - it even made it into the Oxford English Dictionary [which is paywalled, but you can see it linked from the OED's Twitter account - twitter.com/oed/status/1458328605591699460 ] Its acceptance has now achieved cromulency. (I'm going to claim that one if no-one else has;)
    – Tetsujin
    Commented Dec 1, 2022 at 15:57
  • You covered "evil", but what about "good"? And what if one uses the software for purposes that are morally neutral?
    – ikegami
    Commented Dec 2, 2022 at 14:25


There is no legal definition for "evil". Nor is there any generally agreed sense of what constitutes "evil" in the language as a whole. Different people have different ideas of what is and what is not "evil".

Therefore, it is hard to see how such a license provision could be enforced. What actions using the software could a copyright owner reasonably expect a court to prevent or to award damages for? As far as I know, the clause in question has never been enforced in a court action. It seems to be at best an aspiration or a wish. I would not include such a clause in any license I applied to software that I had written.

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    While for many acts it is debatable and subjective whether they are or are not evil, I can certainly imagine many acts where it actually would be possible to convince any judge or jury that THIS definitely qualifies as "evil" - in which case the license might be enforced.
    – Peteris
    Commented Dec 1, 2022 at 7:31

For the specific purpose of copyright licensing, there is no objective legal definition of "evil" that would tell you whether "selling for a profit" is good or evil. If some software so licensed were used to effectuate genocide, the courts could deem that on a balance of probabilities, a reasonable person would understand that genocide is "evil", just as they would find that "selling something for a profit" is "commercial", and also that using said material for educational purposes is not, even if the instructor is paid to teach. Copyright licenses are fundamentally agreements, where the courts primarily inquire into that the parties understood by the wording of the agreement.

Apart from the specific (in)advisability of a vague reference to "evil" in a copyright license, the concept of "evil" does indeed exist in law, and is rather foundational in all legal systems. However, it is so foundational that a law that "penalizes an evil act" would probably be overturned as unconstitutionally vague. Insofar as Shari`a law depends on Arabic terms, not English terms, I exclude discussion of Shari`a prohibitions (hudud).

Common law incorporates many concepts derived from church law. This article focuses on the notion of "evil law", which in the course of the discussion naturally discusses the concept of "evil" in law, indeed in the abstract (indirectly) gives us a succinct definition of evil as "intolerable harm".

The case of US v. Gray is a criminal case touching on "evil", involving violation of 49 USC 46507 penalizing certain statements given "maliciously or with reckless disregard for the safety of human life". The law doesn't define what "maliciously" means, so the judge must instruct jurors. Based on Sand's Modern Federal Jury Instructions, defense proposes that "[t]o act maliciously means to do something with an evil purpose or motive". The judge then instructs the jury as follows:

And then we turn to the question of what we call "malice," "willful or malicious conduct." To act maliciously in this context means to do something with an evil purpose or motive. It means to do something that is knowingly wrong, and here suggestions have been made that Ms. Gray had some malice toward American Airlines. But the [g]overnment has to prove that and you have to evaluate it

but the government chipped away at the instruction, and eventually the jury got an instruction that "what 'malice' means is to act with an evil purpose or an improper motive". Gray was convicted, and appealed – the definition of "maliciously" is the central issue (is it specifically based on "evil"?). The court found in favor of the defendant's more-restrictive definition of malice, one based strictly on evil and not extending to "improper motive". The court's understanding of the difference is summarized in the statement that

The universe of things that are considered improper would encompass anything from wearing a hat indoors to filing a frivolous lawsuit. Evil, on the other hand, is more commonly used to describe something that is morally reprehensible.

So, "evil" can be a thing in law, but it is highly disparaged exactly because there isn't a clear legal definition of "evil".

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    isn't the court using malice as the term defined, not evil, and there is a huge jurisprudence what malice is?
    – Trish
    Commented Nov 30, 2022 at 18:14

it would need to be defined in the license!

If a clause is ambiguous, a court must decide what it means. If a word isn't in the law, it means what the court decides it means. In this case, evil is not defined and lacks a standard definition that all people can agree to. As a result... the clause is ill-defined to non-defined and thus... means nothing.

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    This answer ignores the fundamental concept of Common Law that allows for case law determined by the court to provide a uniform definition of meaning when none has been written in. Lots of laws in Common Law systems have very simple statutory definitions could have massive amounts of case law
    – hszmv
    Commented Dec 1, 2022 at 13:54
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    It is not true that ambiguous clauses are automatically meaningless. Commented Dec 1, 2022 at 14:58

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