In an introduction the paper analyzes two currents of tradition which were essential for the Christian faith and its social aspects: pre-Christian Platonic-Stoic philosophy - adopted by the Fathers of the Church - and the Bible. It became evident that in the Christian tradition justice alone was not viewed as a sufficient means to order society. A second, complementary principle is needed. Various terms are used for the second principle: mercy, beneficence, benevolence, generosity, etc. As important as the second principle is, it remains emotional and insubstantial and is an appeal to generosity. Caritas in veritate regards charity as “at the heart of the Church’s social doctrine”. However, charity is not an immediately applicable social principle. The “primary route of charity” flows into the path of the tenets of social principles, as they have been developed by the social doctrine since the 19th century. The principles of human dignity, of the common good, of solidarity and of subsidiarity, in their mutual connectedness, express how “social charity” can concretely and tangibly be institutionally implemented in a community. But without charity, which keeps all structures and social establishments alive, everything else would break down.