Morissette v. United States, 342 U.S. 246 (1952), is a U.S. Supreme Court case, relevant to the legal topic of criminal intent.

The second class, public welfare offenses, did not require a criminal mental state such as intent or knowledge.

[1] The court wrote that it is "universal... in mature systems of law", that if there is to be punishment for a harmful act, there must be "some mental element".

[1] Crime is a "compound concept, generally constituted only from the concurrence of an evil-meaning mind with an evil-acting hand... As the states codified the common laws of crimes [wrote specific criminal laws], even if enactments were silent on the subject" of intention, and omitted to include it in the code, the state courts assumed the omission did not mean the legislature meant to exclude the requirement that a jury find criminal intent.

The Court notes that public welfare offenses, unlike common law crimes, do not intrinsically involve harm to the State, persons, property, or public morals, but are typified only by "neglect where the law requires care, or inaction where it imposes a duty.

Justice Robert Jackson, writing for a unanimous Court, emphasized the importance of individual criminal intent (mens rea) in the Anglo-American legal tradition, stating famously that crime was "generally constituted only from concurrence of an evil-meaning mind with an evil-doing hand.

The Court notes that public welfare offenses, unlike common law crimes, do not intrinsically involve harm to the State, persons, property, or public morals, but are typified only by "neglect where the law requires care, or inaction where it imposes a duty.