“Integrating the different peoples of the earth”. According to Pope Francis, this is the first challenge to be met, 50 years after the Encyclical “Populorum Progressio”. Upon receiving in audience the participants in the Convention organized by the Dicastery for Promoting Integral Human Development on the 50th anniversary of Paul VI’s encyclical today, Pope Francis recalled that “the duty of solidarity requires us to seek fair ways of sharing, so that there is no longer that dramatic inequality between those who have too much and those who have nothing, between those who discard and those who are discarded”. “Only the path of integration between peoples can permit to humanity a future of peace and hope”, Pope Francis admonished. Hence the need to offer “viable models of social integration” in the awareness that “everyone has a contribution to make to the whole of society, everyone has a special feature that can be useful to enable us to live together, and no-one is excluded from contributing something for the good of all”. “This is both a right and a duty”, the Pope said. “And the principle of subsidiarity guarantees the need for the contribution of everyone, both as individuals and as groups, if we want to create a human society open to all”.