This article presents first the reflections of Popes John Paul II and Francis and the proposals of the Roman Congregations on the welcoming of refugees and immigrants, with special attention to John Paul II’s statement that every society must establish its “cultural equilibrium,” that is to say a compromise between the flourishing of the inherited culture and the cultures brought by the new citizens. The article presents secondly the proposals of the Jesuit Julien Harvey, the founder of le Centre justice et foi, who made a great effort to define the cultural equilibrium for Quebec and suggest practical measures in order to achieve it.