Wherefore the division and appropriation of things which are based on human law, do not preclude the fact that man's needs have to be remedied by means of these very things. Hence whatever certain people have in superabundance is due, by natural law, to the purpose of succoring the poor. For this reason Ambrose [Loc. cit., 2, Objection 3] says, and his words are embodied in the Decretals (Dist. xlvii, can. Sicut ii): "It is the hungry man's bread that you withhold, the naked man's cloak that you store away, the money that you bury in the earth is the price of the poor man's ransom and freedom."
Since, however, there are many who are in need, while it is impossible for all to be succored by means of the same thing, each one is entrusted with the stewardship of his own things, so that out of them he may come to the aid of those who are in need. Nevertheless, if the need be so manifest and urgent, that it is evident that the present need must be remedied by whatever means be at hand (for instance when a person is in some imminent danger, and there is no other possible remedy), then it is lawful for a man to succor his own need by means of another's property, by taking it either openly or secretly: nor is this properly speaking theft or robbery.