49 But charity will never be true charity unless it takes justice into constant account. The Apostle teaches that "he that loveth his neighbor hath fulfilled the law" and he gives the reason: "For, Thou shalt not commit adultery, Thou shalt not kill, Thou shalt not steal . . . and if there be any other commandment, it is comprised in this word: Thou shalt love thy neighbor as thyself. " According to the Apostle, then, all the commandments, including those which are of strict justice, as those which forbid us to kill or to steal, may be reduced to the single precept of true charity. From this it follows that a "charity" which deprives the workingman of the salary to which he has a strict title in justice, is not charity at all, but only its empty name and hollow semblance. The wage-earner is not to receive as alms what is his due in justice. And let no one attempt with trifling charitable donations to exempt himself from the great duties imposed by justice. Both justice and charity often dictate obligations touching on the same subject-matter, but under different aspects; and the very dignity of the workingman makes him justly and acutely sensitive to the duties of others in his regard.
Source: Divini Redemptoris (Vatican.va)