It’s a venerable maxim of criminal jurisprudence that the state must never punish people for their mere thoughts—for their beliefs, desires, fantasies, and unexecuted intentions. This maxim is all but unquestioned, yet its true justification is something of a mystery. In this Essay, I argue that each of the prevailing justifications is deficient, and I conclude by proposing a novel one. The proposed justification captures the widely shared intuition that punishing a person for her mere thoughts isn’t simply disfavored by the balance of reasons but is morally wrongful in itself, an intrinsic (i.e., consequence-independent) injustice to the person punished. The proposed justification also shows how thought’s immunity from punishment relates to a principle of freedom of mind, a linkage often assumed but never explained. In explaining it here, I argue that thought’s penal immunity springs from the interaction of two principles of broad significance: one familiar but poorly understood, the other seemingly unnoticed. The familiar principle is that persons possess a right of mental integrity, a right to be free from the direct and forcible manipulation of their minds. The unnoticed principle, which I label the Enforceability Constraint, is that the state’s authority to punish transgressions of a given type extends no further than its authority to thwart or disrupt such transgressions using direct compulsive force. Heretofore unexamined, the Enforceability Constraint is in fact a signal feature of our system of criminal administration, governing the scope and limits of the criminal law.
"Why is it Wrong to Punish Thought?" Yale L.J. 127, no. 8 (2018): 2342-86.