From Pope Benedict XVI’s encyclical Caritas in Veritate (2009):
“Caritas in veritate” is the principle around which the Church’s social doctrine turns, a principle that takes on practical form in the criteria that govern moral action. I would like to consider two of these in particular, of special relevance to the commitment to development in an increasingly globalized society: justice and the common good.
First of all, justice. Ubi societas, ibi ius: every society draws up its own system of justice. Charity goes beyond justice, because to love is to give, to offer what is “mine” to the other; but it never lacks justice, which prompts us to give the other what is “his”, what is due to him by reason of his being or his acting. I cannot “give” what is mine to the other, without first giving him what pertains to him in justice. If we love others with charity, then first of all we are just towards them. Not only is justice not extraneous to charity, not only is it not an alternative or parallel path to charity: justice is inseparable from charity1, and intrinsic to it. Justice is the primary way of charity or, in Paul VI’s words, “the minimum measure” of it2, an integral part of the love “in deed and in truth” (1 Jn 3:18), to which Saint John exhorts us. On the one hand, charity demands justice: recognition and respect for the legitimate rights of individuals and peoples. It strives to build the earthly city according to law and justice. On the other hand, charity transcends justice and completes it in the logic of giving and forgiving3. The earthly city is promoted not merely by relationships of rights and duties, but to an even greater and more fundamental extent by relationships of gratuitousness, mercy and communion. Charity always manifests God’s love in human relationships as well, it gives theological and salvific value to all commitment for justice in the world.
1 Cf. Paul VI, Encyclical Letter Populorum Progressio (26 March 1967), 22: Acta Apostolicæ Sedis [AAS] 59 (1967), 268; Second Vatican Ecumenical Council, Pastoral Constitution on the Church in the Modern World Gaudium et Spes, 69.
2 Address for the Day of Development (23 August 1968): AAS 60 (1968), 626-627.
3 Cf. John Paul II, Message for the 2002 World Day of Peace: AAS 94 (2002), 132-140.
— Caritas in Veritate 6