Mater et Magistra §155

¹⁵⁵ It is therefore obvious that the solidarity of the human race and Christian brotherhood demand the elimination as far as possible of these discrepancies. With this object in view, people all over the world must co-operate actively with one another in all sorts of ways, so as to facilitate the movement of goods, capital and men from one country to another. We shall have more to say on this point later on.