Question I: What buying and selling are

VERY MANY definitions of these are handed down, from which is drawn the very brief definition which the S. Doctor indicates in the Speculum animae, cap. 2. Venditio est passio mercedis pro pretio, Emptio vero Passio pretii pro mercede, Caspensis uses it Tract. 19. disp. 4. and others apud Fagundez lib. 5. de contract. cap. 1. Bassaeum, verb. Emptio.

NOTE here that the name merx properly signifies only movable things that are sellable lib. 66. ff. de verb. signific. But here merces is taken for merces in the sense of price, insofar as it has the rational character of the object to be priced. It is so taken by Lessius Tom. 1. lib. 2. cap. 11. dub. 1. with the Jurists on leg. 1. ff. de contract. emptionis, et venditionis, and Molina Tom. 2. de iust. tra. 2. disp. 336. who so define it. Therefore it is taken here as signifying the payment, not the merchandise. In this Fagundez is deceived, along with Bassaeus.

It is called Passio, because it is a mutual contract, and this stands in the place of the genitive. It is called mercedis pro pretio, et pretii pro mercede, because of old, before money was invented, there were only exchanges of a horse for an ox; of wine for oil; and of wheat for cloth; but afterwards money was invented on account of the inequality of things, which at the beginning was stamped with the foot of cattle; whence also it was called pecunia, as Pliny testifies lib. 33. cap. 3. and among the Romans it was impressed with the foot of an ox. Hence that proverb of Martius: Bovem habet in lingua, that is, he has been corrupted by money. Hence also Depeculatores were called those who take away moneys by violence, theft, etc. Soon, however, on account of inequality, money was stamped with various metals, at whose price Purchases and Sales began to be made by the law of nations, although as regards the equality of price they are made by the law of nature. On these see Fabianum de monte de empt. et vendit. quaest. 1. Molinam Tom. 2. tract. 2. disp. 336. Fagundez in Prooemio ad lib. 5. de Emptione, etc.

On this (as the S. Doctor says above) perilous matter I shall treat of some things, as being necessary, although very few are found in the Seraphic Doctor.

THREE things, however, are gathered as necessary to Emptionem, et Venditionem, namely Consent, the Thing, and the Price. Concerning Consent it is clear ex Leg. omnibus, ff. de verb. oblig. Concerning the thing it is established ex lege, Nec emptio, ff. de contrahend. empt. Concerning the price it is established ex dicta lege, and the Doctors commonly teach it.

It is PROVED, because this contract is obligatory in both directions; but there is no obligation without consent.

NOTE, however, that the simple contract of Emptionis, et Venditionis entered into with the agreement of forming a written instrument is not perfect unless the writing is made; and any of the contracting parties can withdraw, because under that agreement and condition the contract was entered into, and therefore it is not held to be perfect unless purified, with the condition fulfilled. So the Doctors note on leg. 2. ff. de contract. empt. et leg. contractus, Cod. de fide instrument. et Instit. de empt. et vendit. §. 1. See Molinam tom. 2. de Iustitia, tract. 2. disp. 337. Fagundez lib. 5. cap. 2.

But if mention of the writing has been made, the contract being already perfect, the writing is not necessary. Yet one of the contracting parties can compel the other that the writing be made for the easier proof of the contract, because what does not harm himself and benefits the other, each of the contracting parties is bound to effect. Now the instrument must be paid for by the one who compels the other in this case. See Molinam above with Fagundez.

IF, however, at the beginning of the contract there was agreement about making a writing, it is doubted whether they agreed to this for the greater firmness of the writing and its easier proof; or for the validity of the contract.

COMMONLY they respond that it must be held sufficient for the validity of the contract; others, however, say the opposite.