In the Literal or Written Contract, the formal act, by which an Obligation was superinduced on the Convention, was an entry of the sum due, where it could be specifically ascertained, on the debit side of a ledger. The explanation of this Contract turns on a point or Roman domestic manners, the systematic character and exceeding regularity of bookkeeping in ancient times. There are several minor difficulties of old Roman law, as, for example, the nature of the Slave's Peculium, which are only cleared up when we recollect that a Roman household consisted or a number of persons strictly accountable to its head, and that every single item of domestic receipt and expenditure, after being entered in waste books, was transferred at stated periods to a general household ledger. There are some obscurities, however, in the descriptions we have received of the Literal Contract, the fact being that the habit of keeping books ceased to be universal in later times, and the expression "Literal Contract" came to signify a form of engagement entirely different from that originally understood. We are not, therefore, in a position to say, with respect to the primitive Literal Contract, whether the obligation was created by a simple entry on the part of the creditor, or whether the consent of the debtor or a corresponding entry in his own books was necessary to give it legal effect. The essential point is however established that, in the case of this Contract, all formalities were dispensed with on a condition being complied with. This is another step downwards in the history of contract-law.
The Contract which stands next in historical succession, the Real Contract, shows a great advance in ethical conceptions.
Whenever any agreement had for its object the deliver of a specific thing -- and this is the case with the large majority of simple engagements -- the Obligation was drawn down as soon as the delivery had actually taken place. Such a result must have involved a serious innovation on the oldest ideas of Contract;for doubtless, in the primitive times, when a Contracting party had neglected to clothe his agreement in a stipulation, nothing done in pursuance of the agreement would be recognised by the law A person who had paid over money on loan would be unable to sue for its repayment unless he had formally stipulated for it. But, in the Real Contract, performance on one side is allowed to impose a legal duty on the other -- evidently on ethical grounds.
For the first time then moral considerations appear as an ingredient in Contract-law, and the Real Contract differs from its two predecessors in being rounded on these, rather than on respect for technical forms or on deference to Roman domestic habits.
We now reach the fourth class, or Consensual Contracts, the most interesting and important of all. Four specified Contracts were distinguished by this name: Mandatum, i.e. Commission or Agency; Societas or Partnership; Emtio Venditio or Sale; and Locatio Conductio or Letting and Hiring. A few pages ago, after stating that a Contract consisted of a Pact or Convention to which an Obligation had been superadded, I spoke of certain acts or formalities by which the law permitted the Obligation to be attracted to the Pact. I used this language on account of the advantage of a general expression, but it is not strictly correct unless it be understood to include the negative as well as the positive. For, in truth, the peculiarity of these Consensual Contracts is that no formalities are required to create them out of the Pact. Much that is indefensible, and much more that is obscure, has been written about the Consensual Contracts, and it has even been asserted that in them the consent of the Parties is more emphatically given than in any other species of agreement.
But the term Consensual merely indicates that the Obligation is here annexed at once to the Consensus. The Consensus, or mutual assent of the parties, is the final and crowning ingredient in the Convention, and it is the special characteristic of agreements falling under one of the four heads of Sale, Partnership, Agency, and Hiring, that, as soon as the assent of the parties has supplied this ingredient, there is at once a Contract. The Consensus draws with it the Obligation, performing, in transactions of the sort specified, the exact functions which are discharged, in the other contracts, by the Res or Thing, by the Verba stipulationis, and by the Literae or written entry in a ledger. Consensual is therefore a term which does not involve the slightest anomaly, but is exactly analogous to Real, Verbal, and Literal.
