73 Sincere dialogue between cultures, as between individuals, paves the way for ties of brotherhood. Plans proposed for man's betterment will unite all nations in the joint effort to be undertaken, if every citizen—be he a government leader, a public official, or a simple workman—is motivated by brotherly love and is truly anxious to build one universal human civilization that spans the globe. Then we shall see the start of a dialogue on man rather than on the products of the soil or of technology. This dialogue will be fruitful if it shows the participants how to make economic progress and how to achieve spiritual growth as well; if the technicians take the role of teachers and educators; if the training provided is characterized by a concern for spiritual and moral values, so that it ensures human betterment as well as economic growth. Then the bonds of solidarity will endure, even when the aid programs are past and gone. It is not plain to all that closer ties of this sort will contribute immeasurably to the preservation of world peace?
Source: Populorum Progressio (Vatican.va)