Thomas Aquinas, Summa Theologiae

Objection 1: It would seem that the seller is not bound to state the defects of the thing sold. Since the seller does not bind the buyer to buy, he would seem to leave it to him to judge of the goods offered for sale. Now judgment about a thing and knowledge of that thing belong to the same person. Therefore it does not seem imputable to the seller if the buyer be deceived in his judgment, and be hurried into buying a thing without carefully inquiring into its condition.

Objection 2: Further, it seems foolish for anyone to do what prevents him carrying out his work. But if a man states the defects of the goods he has for sale, he prevents their sale: wherefore Tully (De Offic. iii, 13) pictures a man as saying: "Could anything be more absurd than for a public crier, instructed by the owner, to cry: 'I offer this unhealthy horse for sale?'" Therefore the seller is not bound to state the defects of the thing sold.

Objection 3: Further, man needs more to know the road of virtue than to know the faults of things offered for sale. Now one is not bound to offer advice to all or to tell them the truth about matters pertaining to virtue, though one should not tell anyone what is false. Much less therefore is a seller bound to tell the faults of what he offers for sale, as though he were counseling the buyer.

Objection 4: Further, if one were bound to tell the faults of what one offers for sale, this would only be in order to lower the price. Now sometimes the price would be lowered for some other reason, without any defect in the thing sold: for instance, if the seller carry wheat to a place where wheat fetches a high price, knowing that many will come after him carrying wheat; because if the buyers knew this they would give a lower price. But apparently the seller need not give the buyer this information. Therefore, in like manner, neither need he tell him the faults of the goods he is selling.

On the contrary, Ambrose says (De Offic. iii, 10): "In all contracts the defects of the salable commodity must be stated; and unless the seller make them known, although the buyer has already acquired a right to them, the contract is voided on account of the fraudulent action."

I answer that, It is always unlawful to give anyone an occasion of danger or loss, although a man need not always give another the help or counsel which would be for his advantage in any way; but only in certain fixed cases, for instance when someone is subject to him, or when he is the only one who can assist him. Now the seller who offers goods for sale, gives the buyer an occasion of loss or danger, by the very fact that he offers him defective goods, if such defect may occasion loss or danger to the buyer---loss, if, by reason of this defect, the goods are of less value, and he takes nothing off the price on that account---danger, if this defect either hinder the use of the goods or render it hurtful, for instance, if a man sells a lame for a fleet horse, a tottering house for a safe one, rotten or poisonous food for wholesome. Wherefore if such like defects be hidden, and the seller does not make them known, the sale will be illicit and fraudulent, and the seller will be bound to compensation for the loss incurred.

On the other hand, if the defect be manifest, for instance if a horse have but one eye, or if the goods though useless to the buyer, be useful to someone else, provided the seller take as much as he ought from the price, he is not bound to state the defect of the goods, since perhaps on account of that defect the buyer might want him to allow a greater rebate than he need. Wherefore the seller may look to his own indemnity, by withholding the defect of the goods.

Reply to Objection 1: Judgment cannot be pronounced save on what is manifest: for "a man judges of what he knows" (Ethic. i, 3). Hence if the defects of the goods offered for sale be hidden, judgment of them is not sufficiently left with the buyer unless such defects be made known to him. The case would be different if the defects were manifest.

Reply to Objection 2: There is no need to publish beforehand by the public crier the defects of the goods one is offering for sale, because if he were to begin by announcing its defects, the bidders would be frightened to buy, through ignorance of other qualities that might render the thing good and serviceable. Such defect ought to be stated to each individual that offers to buy: and then he will be able to compare the various points one with the other, the good with the bad: for nothing prevents that which is defective in one respect being useful in many others.

Reply to Objection 3: Although a man is not bound strictly speaking to tell everyone the truth about matters pertaining to virtue, yet he is so bound in a case when, unless he tells the truth, his conduct would endanger another man in detriment to virtue: and so it is in this case.

Reply to Objection 4: The defect in a thing makes it of less value now than it seems to be: but in the case cited, the goods are expected to be of less value at a future time, on account of the arrival of other merchants, which was not foreseen by the buyers. Wherefore the seller, since he sells his goods at the price actually offered him, does not seem to act contrary to justice through not stating what is going to happen. If however he were to do so, or if he lowered his price, it would be exceedingly virtuous on his part: although he does not seem to be bound to do this as a debt of justice.

Articulus 3

Argumentum 1

Ad tertium sic proceditur. Videtur quod venditor non teneatur dicere vitium rei venditae. Cum enim venditor emptorem ad emendum non cogat, videtur eius iudicio rem quam vendit supponere. Sed ad eundem pertinet iudicium et cognitio rei.

Non ergo videtur imputandum venditori si emptor in suo iudicio decipitur, praecipitanter emendo, absque diligenti inquisitione de conditionibus rei.

Argumentum 2

Praeterea, stultum videtur quod aliquis id faciat unde eius operatio impediatur. Sed si aliquis vitia rei vendendae indicet, impedit suam venditionem, ut enim tullius, in libro de offic., inducit quendam dicentem, quid tam absurdum quam si, domini iussu, ita praeco praediceret, domum pestilentem vendo? ergo venditor non tenetur dicere vitia rei venditae.

Argumentum 3

Praeterea, magis necessarium est homini ut cognoscat viam virtutis quam ut cognoscat vitia rerum quae venduntur. Sed homo non tenetur cuilibet consilium dare et veritatem dicere de his quae pertinent ad virtutem, quamvis nulli debeat dicere falsitatem.

Ergo multo minus tenetur venditor vitia rei venditae dicere, quasi consilium dando emptori.

Argumentum 4

Praeterea, si aliquis teneatur dicere defectum rei venditae, hoc non est nisi ut minuatur de pretio. Sed quandoque diminueretur de pretio etiam sine vitio rei venditae, propter aliquid aliud, puta si venditor deferens triticum ad locum ubi est carestia frumenti, sciat multos posse venire qui deferant; quod si sciretur ab ementibus, minus pretium darent.

Huiusmodi autem non oportet dicere venditorem, ut videtur.

Ergo, pari ratione, nec vitia rei venditae.

Sed Contra

Sed contra est quod Ambrosius dicit, in III de offic., in contractibus vitia eorum quae veneunt prodi iubentur, ac nisi intimaverit venditor, quamvis in ius emptoris transierint, doli actione vacuantur.

Corpus

Respondeo dicendum quod dare alicui occasionem periculi vel damni semper est illicitum, quamvis non sit necessarium quod homo alteri semper det auxilium vel consilium pertinens ad eius qualemcumque promotionem, sed hoc solum est necessarium in aliquo casu determinato, puta cum alius eius curae subdatur, vel cum non potest ei per alium subveniri. Venditor autem, qui rem vendendam proponit, ex hoc ipso dat emptori damni vel periculi occasionem quod rem vitiosam ei offert, si ex eius vitio damnum vel periculum incurrere possit, damnum quidem, si propter huiusmodi vitium res quae vendenda proponitur minoris sit pretii, ipse vero propter huiusmodi vitium nihil de pretio subtrahat; periculum autem, puta si propter huiusmodi vitium usus rei reddatur impeditus vel noxius, puta si aliquis alicui vendat equum claudicantem pro veloci, vel ruinosam domum pro firma, vel cibum corruptum sive venenosum pro bono. Unde si huiusmodi vitia sint occulta et ipse non detegat, erit illicita et dolosa venditio, et tenetur venditor ad damni recompensationem. Si vero vitium sit manifestum, puta cum equus est monoculus; vel cum usus rei, etsi non competat venditori, potest tamen esse conveniens aliis; et si ipse propter huiusmodi vitium subtrahat quantum oportet de pretio, non tenetur ad manifestandum vitium rei.

Quia forte propter huiusmodi vitium emptor vellet plus subtrahi de pretio quam esset subtrahendum. Unde potest licite venditor indemnitati suae consulere, vitium rei reticendo.

Ad 1

Ad primum ergo dicendum quod iudicium non potest fieri nisi de re manifesta, unusquisque enim iudicat quae cognoscit, ut dicitur in I ethic..

Unde si vitia rei quae vendenda proponitur sint occulta, nisi per venditorem manifestentur, non sufficienter committitur emptori iudicium. Secus autem esset si essent vitia manifesta.

Ad 2

Ad secundum dicendum quod non oportet quod aliquis per praeconem vitium rei vendendae praenuntiet, quia si praediceret vitium, exterrerentur emptores ab emendo, dum ignorarent alias conditiones rei, secundum quas est bona et utilis. Sed singulariter est dicendum vitium ei qui ad emendum accedit, qui potest simul omnes conditiones ad invicem comparare, bonas et malas, nihil enim prohibet rem in aliquo vitiosam, in multis aliis utilem esse.

Ad 3

Ad tertium dicendum quod quamvis homo non teneatur simpliciter omni homini dicere veritatem de his quae pertinent ad virtutes, teneretur tamen in casu illo de his dicere veritatem quando ex eius facto alteri periculum immineret in detrimentum virtutis nisi diceret veritatem. Et sic est in proposito.

Ad 4

Ad quartum dicendum quod vitium rei facit rem in praesenti esse minoris valoris quam videatur, sed in casu praemisso, in futurum res expectatur esse minoris valoris per superventum negotiatorum, qui ab ementibus ignoratur. Unde venditor qui vendit rem secundum pretium quod invenit, non videtur contra iustitiam facere si quod futurum est non exponat. Si tamen exponeret, vel de pretio subtraheret, abundantioris esset virtutis, quamvis ad hoc non videatur teneri ex iustitiae debito.