90 If the members of the body social are, as was said, reconstituted, and if the directing principle of economic-social life is restored, it will be possible to say in a certain sense even of this body what the Apostle says of the mystical body of Christ: "The whole body (being closely joined and knit together through every joint of the system according to the functioning in due measure of each single part) derives its increase to the building up of itself in love."
Source: Quadragesimo Anno (Vatican.va)