Liability under criminal statutes prefers a culpable mental
state. The Latin phrase actus non facit reum nisi mens sit rea,
translated as “[t]he act does not make the person guilty unless
that person’s mind is guilty,” illustrates the classic principle that
some degree of guilty knowledge—or mens rea—is required to
impose criminal penalties. Willful, one such mens rea, is
perhaps the most conflated, confusing, and confounding of all
criminal mental states. Willful is also often spelled as wilful,
willfull or even willfull in various statutory texts. As Justice
Jackson wrote in Spies v. United States, willful “is a word of
many meanings, its construction often being influenced by its
context.” In American criminal law generally, willful is the legal
lizard of mens rea, a chameleon-like term that defies a single,
constant definition in New York or any other jurisdiction, and is
thus a “wild” term.
When a statutory term has two different meanings, judicial interpretation turns on the intention of lawmakers, which is paramount. Absent legislative guidance, courts consider context, purpose, and spirit of the enactment and even dictionary definitions, giving force to particular words of a statute. In criminal statutes, willful is a moving target that defies a basic, long-established constitutional principle of explicitness.