This chapter explains the principle of the universal destination of earthly goods as it has been affirmed by the magisterium of the Catholic Church, based upon scriptural and patristic sources and on the thought of Saint Thomas Aquinas, and developed especially since Rerum novarum. The principle is one of the most consistent doctrines of that evolving magisterium, with only minor adjustments of expression, extension to new matters, and differing emphases according to contingent circumstances and the relative force of opposing errors at different times. After a brief introduction (sec. I), the chapter presents in chronological order the evolution of the formulations of the principle before the Second Vatican Council (sec. II) and from there to Pope Francis (sec. III). The purpose of this sort of exposition – chronological and textual – is to furnish the reader with the main texts of the social doctrine of the Church about the principle, so that the stability of the teaching may appear as self-evident. For the main thesis is always the same: the priority of the universal destination of earthly goods as an end, and its compatibility with a strong right to private property as a means.