CCC 1905

In keeping with the social nature of man, the good of each individual is necessarily related to the common good, which in turn can be defined only in reference to the human person:

Do not live entirely isolated, having retreated into yourselves, as if you were already justified, but gather instead to seek the common good together.²⁵ Ep. Barnabae, 4,10: PG 2, 734PG — Patrologia Graeca (Migne).