SALE AND PURCHASE. - Sale, or *compravendita*, is the contract by which one person (the seller) transfers ownership of a thing or another right to another person (the buyer) in exchange for a price (art. 1470 of the Civil Code). This contract, which is among the most important, is "onerous" and, by its nature, "non-aleatory" (see CONTRATTO).
In Italian civil law, *compravendita* generally effects the transfer of ownership as soon as the consent of the parties has been given, unless the thing sold is a *genus*, i.e., a quantity of fungible goods (see COSA); in which case it is also necessary that the goods be identified (arts. 1376-78). However, it is never necessary that the thing be actually delivered or that the price be paid. The same principles are followed by foreign legislations: only in the case of the sale of immovable property do some of them subordinate the transfer of ownership to the registration of the contract in public registers.
The seller is obliged: 1) to deliver the thing to the buyer; 2) to ensure that the buyer acquires ownership of the thing, if this is not an immediate effect of the contract; 3) to guarantee the buyer against eviction (i.e., in the case where a third party claims rights over the thing), or in the case where the thing is affected by defects that render it unfit for use or substantially diminish its value (arts. 1476). The buyer, for his part, must pay the agreed price.
The many problems that this most common contract presents to moral theology concern the just price, competition, hoarding, profit, auction (see LICITAZIONE), monopoly, mandate, representation, etc. (see the individual entries).
For the sale of ecclesiastical goods see BENI ECCLESIASTICI; see also SIMONIA.