This book rewrites the history of Christian peace ethics. Christian reflection on reducing
violence or overcoming war has roots in ancient Roman philosophy and eventually grew to
influence modern international law. This historical overview begins with Cicero the source of
Christian authors like Augustine and Thomas Aquinas. It is highly debatable whether Augustine
had a systematic interest in just war or whether his writings were used to develop a systematic
just war teaching only by the later tradition. May Christians justifiably use force to overcome
disorder and achieve peace? The book traces the classical debate from Thomas Aquinas to early
modern-age thinkers like Vitoria Suarez Martin Luther Hugo Grotius and Immanuel Kant. It
highlights the diversity of the approaches of theologians philosophers and lawyers. Modern
cosmopolitianism and international law-thinking it shows are rooted in the Spanish
Scholastics where Grotius and Kant each found the inspiration to inaugurate a modern peace
ethic. In the 20th century the tradition has taken aim not only at reducing violence and
overcoming war but at developing a constructive ethic of peace building as is reflected in
Pope John Paul II's teaching.
