44 Today, on the contrary the conviction is widespread that all men are equal in natural dignity; and so, on the doctrinal and theoretical level, at least, no form of approval is being given to racial discrimination. All this is of supreme significance for the formation of a human society animated by the principles We have mentioned above, for man's awareness of his rights must inevitably lead him to the recognition of his duties. The possession of rights involves the duty of implementing those rights, for they are the expression of a man's personal dignity. And the possession of rights also involves their recognition and respect by other people.
Source: Pacem in Terris (Vatican.va)