resting each on its own independent ground, as is prescribed by the constitution, and as can be more fully ascertained by perusing the same. 4 Moreover, those obligations which are contracted by consent alone are dissolved by a contrary agreement. For instance, if Titius and Seius agree that the latter shall buy an estate at Tusculum for a hundred aurei, and then before execution on either side by payment of the price or delivery of the estate they arrange to abandon the sale, they are both released. The case is the same with hire and the other contracts which are formed by consent alone. BOOK IV. TITLE I. OF OBLIGATIONS ARISING FROM DELICT Having treated in the preceding Book of contractual and quasicontractual obligations, it remains to inquire into obligations arising from delict. The former, as we remarked in the proper place, are divided into four kinds; but of these latter there is but one kind, for, like obligations arising from real contracts, they all originate in some act, that is to say, in the delict itself, such as a theft, a robbery, wrongful damage, or an injury. 1 Theft is a fraudulent dealing with property, either in itself, or in its use, or in its possession: an offence which is prohibited by natural law. 2 The term furtum, or theft, is derived either from furvum, meaning 'black,' because it is effected secretly and under cover, and usually by night: or from fraus, or from ferre, meaning 'carrying off'; or from the Greek word phor, thief, which indeed is itself derived from pherein, to carry off. 3 There are two kinds of theft, theft detected in the commission, and simple theft: the possession of stolen goods discovered upon search, and the introduction of stolen goods, are not (as will appear below) so much specific kinds of theft as actionable circumstances connected with theft. A thief detected in the commission is termed by the Greeks ep'autophoro; in this kind is included not only he who is actually caught in the act of theft, but also he who is detected in the place where the theft is committed; for instance, one who steals from a house, and is caught before he has got outside the door; or who steals olives from an olive garden, or grapes from a vineyard, and is caught while still in the olive garden or vineyard. And the definition of theft detected in the commission must be even further extended, so as to include the thief who is caught or even seen with the stolen goods still in his hands, whether the place be public or private, and whether the person who sees or catches him be the owner of the property, or some third person, provided he has not yet escaped to the place where he intended to take and deposit his booty: for if he once escapes there, it is not theft detected in the commission, even if he be found with the stolen goods upon him. What is simple theft is clear from what has been said: that is to say, it is all theft which is not detected in the commission.