What (If Anything) Can Justify Criminalization?

This paper asks whether criminalization—the act of making certain action-types crimes—is justified. In answer, the paper presents an argument—the argument from human interaction—to show that criminalization is unjustified. The paper begins by considering the five arguments usually brought to justify criminalization: the arguments from protecting persons and property, from preventing undesirable conduct, from maintaining public order, from a chaos of vengeance, and from democratic expression of disgust. The paper shows that all of these arguments have serious weaknesses. The paper then presents the argument from human interaction, and tries to show that it is a plausible argument. From this result and the failure of the five main justifications, the paper concludes that it is unclear that criminalization is justified.