Aquinas on When You Can Steal

Summa Theologiae
Second Part of the Second Part
Question 66

Article 7. Whether it is lawful to steal through stress of need?

I answer that, Things which are of human right cannot derogate from natural right or Divine right. Now according to the natural order established by Divine Providence, inferior things are ordained for the purpose of succoring man's needs by their means. 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., Article 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.

Reply to Objection 1. This decretal considers cases where there is no urgent need.

Reply to Objection 2. It is not theft, properly speaking, to take secretly and use another's property in a case of extreme need: because that which he takes for the support of his life becomes his own property by reason of that need.

Reply to Objection 3. In a case of a like need a man may also take secretly another's property in order to succor his neighbor in need.