In “Morality Influences How People Apply the Ignorance of the Law Defense,” Alter, Kernochan, Darley, et al. (2007) present the findings of four empirical studies showing how the perceived morality of the defendant influences decisions regarding determinations of guilt. In all four of the studies, the researchers found that laypeople will judge a defendant more harshly when the defendant is perceived of as an immoral person—regardless of whether the defendant claims ignorance of the law. The authors contend that the law should reflect the “moral intuitions” of the people, allowing for a differentiation between the actus reus (the criminal act) and the mens rea (criminal intent). Complicating matters is the fact that American legal precedent does not allow for an ignorance of the law defense; a person cannot hide behind claims to not know the law. A person who genuinely does not know that an act is criminal cannot have criminal intent: something that presents a moral conundrum for legal analysts. If intent is equated with moral culpability and thus, legal definitions of guilt, then the law must also be able to distinguish between genuine criminal intent and genuine ignorance. As Rosenweig (2013) puts it, the no-ignorance standard applies to crimes that are “self-evident wrongs,” and there are a slew of acts deemed criminal that are not necessarily self-evidently so (p. 1). A prime example would be not knowing that a certain...

Many laws are either obscure or too complex to understand, or breaking those laws might not actually cause harm.
The reasoning behind the denial of ignorance principle is utilitarian in nature, according to Alter, Kernochan, Darley, et al. (2007). One reason is that it is categorically impossible to determine definitively whether a person was ignorant of the law. It is simpler to determine knowledge of the law, such as when a person has professional authority to know about the issues pertinent to the case. Yet proving ignorance is not possible. Another utilitarian function of the denial of ignorance as a valid excuse is that it does encourage citizens to take a more active part in learning about the law. Participating in a democracy does demand a great degree of personal responsibility. Finally, the slippery slope argument applies: if ignorance were permitted as a valid excuse, it could lead to individuals claiming all sorts of unique personal interpretations of the law. To maintain the integrity of the law and prevent too much ambiguity, the courts have consistently held that ignorance is not a legitimate defense.

Firmly denying claims of ignorance does lead to problems, though. For one,…