The Popes' New Order, edited by Philip Hughes, systematically summarizes Catholic social teaching from Leo XIII to Pius XII, outlining principles on labor, property, family, state, and the common good, building from Rerum Novarum's focus on workers to later popes addressing global crises like depression and war, advocating for Christian solutions to societal ills through spiritual principles, natural law, and the dignity of the human person against ideologies like liberalism and socialism, aiming for social justice and a renewed Christian social order.