Objection 1: It would seem that theft is not always a sin. For no sin is commanded by God, since it is written (Ecclus.15:21): |He hath commanded no man to do wickedly.| Yet we find that God commanded theft, for it is written (Ex.12:35,36): |And the children of Israel did as the Lord had commanded Moses [Vulg.: 'as Moses had commanded']. . . and they stripped the Egyptians.| Therefore theft is not always a sin.
Objection 2: Further, if a man finds a thing that is not his and takes it, he seems to commit a theft, for he takes another's property. Yet this seems lawful according to natural equity, as the jurists hold. [*See loc. cit. in Reply.] Therefore it seems that theft is not always a sin.
Objection 3: Further, he that takes what is his own does not seem to sin, because he does not act against justice, since he does not destroy its equality. Yet a man commits a theft even if he secretly take his own property that is detained by or in the safe-keeping of another. Therefore it seems that theft is not always a sin.
On the contrary, It is written (Ex.20:15): |Thou shalt not steal.|
I answer that, If anyone consider what is meant by theft, he will find that it is sinful on two counts. First, because of its opposition to justice, which gives to each one what is his, so that for this reason theft is contrary to justice, through being a taking of what belongs to another. Secondly, because of the guile or fraud committed by the thief, by laying hands on another's property secretly and cunningly. Wherefore it is evident that every theft is a sin.
Reply to Objection 1: It is no theft for a man to take another's property either secretly or openly by order of a judge who has commanded him to do so, because it becomes his due by the very fact that it is adjudicated to him by the sentence of the court. Hence still less was it a theft for the Israelites to take away the spoils of the Egyptians at the command of the Lord, Who ordered this to be done on account of the ill-treatment accorded to them by the Egyptians without any cause: wherefore it is written significantly (Wis.10:19): |The just took the spoils of the wicked.|
Reply to Objection 2: With regard to treasure-trove a distinction must be made. For some there are that were never in anyone's possession, for instance precious stones and jewels, found on the seashore, and such the finder is allowed to keep [*Dig. I, viii, De divis. rerum: Inst. II, i, De rerum divis.]. The same applies to treasure hidden underground long since and belonging to no man, except that according to civil law the finder is bound to give half to the owner of the land, if the treasure trove be in the land of another person [*Inst. II, i, 39: Cod. X, xv, De Thesauris]. Hence in the parable of the Gospel (Mat.13:44) it is said of the finder of the treasure hidden in a field that he bought the field, as though he purposed thus to acquire the right of possessing the whole treasure. On the other Land the treasure-trove may be nearly in someone's possession: and then if anyone take it with the intention, not of keeping it but of returning it to the owner who does not look upon such things as unappropriated, he is not guilty of theft. In like manner if the thing found appears to be unappropriated, and if the finder believes it to be so, although he keep it, he does not commit a theft [*Inst. II, i, 47]. In any other case the sin of theft is committed [*Dig. XLI, i, De acquirend, rerum dominio, 9: Inst. II, i, 48]: wherefore Augustine says in a homily (Serm. clxxviii; De Verb. Apost.): |If thou hast found a thing and not returned it, thou hast stolen it| (Dig. xiv, 5, can. Si quid invenisti).
Reply to Objection 3: He who by stealth takes his own property which is deposited with another man burdens the depositary, who is bound either to restitution, or to prove himself innocent. Hence he is clearly guilty of sin, and is bound to ease the depositary of his burden. On the other hand he who, by stealth, takes his own property, if this be unjustly detained by another, he sins indeed; yet not because he burdens the retainer, and so he is not bound to restitution or compensation: but he sins against general justice by disregarding the order of justice and usurping judgment concerning his own property. Hence he must make satisfaction to God and endeavor to allay whatever scandal he may have given his neighbor by acting this way.
Whether theft is a mortal sin?
Objection 1: It would seem that theft is not a mortal sin. For it is written (Prov.6:30): |The fault is not so great when a man hath stolen.| But every mortal sin is a great fault. Therefore theft is not a mortal sin.
Objection 2: Further, mortal sin deserves to be punished with death. But in the Law theft is punished not by death but by indemnity, according to Ex.22:1, |If any man steal an ox or a sheep . . . he shall restore have oxen for one ox, and four sheep for one sheep.| Therefore theft is not a mortal sin.
Objection 3: Further, theft can be committed in small even as in great things. But it seems unreasonable for a man to be punished with eternal death for the theft of a small thing such as a needle or a quill. Therefore theft is not a mortal sin.
On the contrary, No man is condemned by the Divine judgment save for a mortal sin. Yet a man is condemned for theft, according to Zech.5:3, |This is the curse that goeth forth over the face of the earth; for every thief shall be judged as is there written.| Therefore theft is a mortal sin.
I answer that, As stated above (Q, A; FS, Q, A), a mortal sin is one that is contrary to charity as the spiritual life of the soul. Now charity consists principally in the love of God, and secondarily in the love of our neighbor, which is shown in our wishing and doing him well. But theft is a means of doing harm to our neighbor in his belongings; and if men were to rob one another habitually, human society would be undone. Therefore theft, as being opposed to charity, is a mortal sin.
Reply to Objection 1: The statement that theft is not a great fault is in view of two cases. First, when a person is led to thieve through necessity. This necessity diminishes or entirely removes sin, as we shall show further on (A). Hence the text continues: |For he stealeth to fill his hungry soul.| Secondly, theft is stated not to be a great fault in comparison with the guilt of adultery, which is punished with death. Hence the text goes on to say of the thief that |if he be taken, he shall restore sevenfold . . . but he that is an adulterer . . . shall destroy his own soul.|
Reply to Objection 2: The punishments of this life are medicinal rather than retributive. For retribution is reserved to the Divine judgment which is pronounced against sinners |according to truth| (Rom.2:2). Wherefore, according to the judgment of the present life the death punishment is inflicted, not for every mortal sin, but only for such as inflict an irreparable harm, or again for such as contain some horrible deformity. Hence according to the present judgment the pain of death is not inflicted for theft which does not inflict an irreparable harm, except when it is aggravated by some grave circumstance, as in the case of sacrilege which is the theft of a sacred thing, of peculation, which is theft of common property, as Augustine states (Tract.1, Super Joan.), and of kidnaping which is stealing a man, for which the pain of death is inflicted (Ex.21:16).
Reply to Objection 3: Reason accounts as nothing that which is little: so that a man does not consider himself injured in very little matters: and the person who takes such things can presume that this is not against the will of the owner. And if a person take such like very little things, he may be proportionately excused from mortal sin. Yet if his intention is to rob and injure his neighbor, there may be a mortal sin even in these very little things, even as there may be through consent in a mere thought.