During his life and ministry, St. Ambrose composed several works. Perhaps most notable among these is his catechetical work on the sacraments, De mysteriis ("On the Mysteries").
Given all of the heated commentary generated by the so-called economic paragraphs of Evangelii gaudium, it bears noting that in Pope Paul VI's penultimate encyclical (Humanae Vitae was his ultimate), Populorum progresso, the Pontiff turned to one of Ambrose's letters to make a particularly provocative point: that the right to private property is not absolute.
Everyone knows that the Fathers of the Church laid down the duty of the rich toward the poor in no uncertain terms. As St. Ambrose put it: "You are not making a gift of what is yours to the poor man, but you are giving him back what is his. You have been appropriating things that are meant to be for the common use of everyone. The earth belongs to everyone, not to the rich." These words indicate that the right to private property is not absolute and unconditional (par. 23)I am not shy about once again noting that together Populorum progresso and Humanae vitae, Evangelii Nuntiandi forms a triptych of Pope Paul's papal magisterium.
If you're interested in reading more on this, I direct you to a paper of fairly recent vintage, one I recently read, by Siegfried Van Duffel and Dennis Yap, entitled "Distributive Justice before the Eighteenth Century: The Right of Necessity."
Apparently anticipating Pope Francis by more than 1,600 years, it was St. Ambrose who wrote: "It is a better thing to save souls for the Lord than to save treasures. He who sent forth his apostles without gold had not need of gold to form his Church. The Church possesses gold, not to hoard, but to scatter abroad and come to the aid of the unfortunate."
St. Ambrose, blessed doctor, pray for us.