Antonio Rosmini-Serbati (1797-1855) was one of the first natural law scholars to bring natural law thinking into a conversation with the market economic order that was beginning to emerge in Europe in the 19th century. His reflections on matters such as the origin, nature, and limits of private property, the role of the state, and the nature of human reason show him to be a unique, innovative thinker who nonetheless was determined to work within the parameters of Catholic doctrine. Many of these ideas are concretized in his seminal work The Constitution Under Social Justice, a text that has profound instights to offer those today seeking to integrate theology, philosophy, and economics into their conceptions of a social order that aspires to be both free and just.