Abstract: This encyclopedia entry contrasts opposing approaches to the legal aspects of money creation. The divide is stark, pitting those who understand law as instrumental, regulatory, or managerial against those who identify it as essential, enabling, or literally constitutive of money and exchange. Those positions are rooted in fundamentally different assumptions about the nature of value, the functions of money, the interests and capacities of sovereign authorities, and the nature of historical change. The contrast exposes the stakes of the divergence for matters ranging from public policy to our understanding of the market. The essay concludes with a case study that approaches the National Banking Acts as an episode of monetary engineering.