De Iustitia et Iure (On Justice and Law)
1553
Summary
Domingo de Soto's systematic treatment of justice and law, published in 1553. Soto develops a rigorous natural law analysis of property rights, the just price, usury, and commercial ethics. His treatment of the just price — as determined by common market estimation rather than by moral decree — contributed to the emerging understanding that voluntary exchange and market prices have an inherent legitimacy grounded in natural law.