As the first systematic theology of its kind, the ecumenical construction synthesizes the strengths of what are typically considered two disparate branches of Christianity, namely, Roman Catholicism and Anabaptism. Focusing on the celebrated Jesuit neo-Scholastic theologian Luis de Molina (1535-1600) and the evangelical peace communities from the early modern period onward, this system integrates the best in Catholic philosophical theology with the best historical implementations of the Free Church ecclesiological tradition.