If the question be asked: How ought man to use his possessions? the Church replies without hesitation: “As to this point, man ought not regard external goods as his own, but as common so that, in fact, a person should readily share them when he sees others in need. No one, certainly, is obliged to assist others out of what is required for his own necessary use or for that of his family, . . . But when the demands of necessity and propriety have been met, it is a duty to give to the poor out of that which remains. (#35-36)

~  Pope Leo XIII in Rerum Novarum (On the Condition of Workers)