Substance. Even a cursory review of all of Roman private law would be too long to provide. Instead, it may be more useful to consider selected aspects of Roman law in a few important areas. This selection may give some idea of the strengths and limitations of the Roman legal system concerning contracts, property damage, ownership, and “crimes” within the private law.
Contracts. Roman law recognized a variety of different kinds of contract, some defined by their forms (e.g., an oral question and answer using certain key words) and others by substance of the underlying transaction (e.g., sale or rental, but not barter or lending at interest). Among the latter group were the “consensual” contracts; these did not require any written or oral expression at all, merely the consent or agreement of both parties. These formless contracts were convenient ways of conducting the transactions they covered, such as sale, rental, hiring, and formation of partnerships. Thus, they seem to have been created in the interest of more efficient commerce. A later development, perhaps of the first century b.c.e., was the inclusion of certain implied warranties. So, for instance, it became part of the definition of a sale that the seller guaranteed to the buyer that no third party had a legal claim to the item being sold. If a dispute over one of these contracts came to court, the judge decided what each party should pay “in accord with good faith.” Many other legal systems (and, indeed, early Roman law) preferred an all-or-nothing system in which, for instance, a buyer could be liable only for the full purchase price or nothing at all. The “good faith” standard is clearly better, among other things, in accounting for partial performance, as when the seller delivers some but not all of the other promised goods.
Transactional Limitations. This system was not without its problems. Not all transactions were covered by consensual contract. There was no sale of generic items or sale without a fixed price. Generic items could be, say, any ten bushels of wheat instead of a particular ten bushels. Note that this means there could be no sale of items not yet manufactured or (except in certain circumstances) crops not yet grown. The other rule means that one could not sell at a price to be determined later (contrast modern adjustable-rate loans, which vary with the prime rate). For dealings between individuals, these limitations were not necessarily big problems. For larger and more sophisticated businesses, however, the difficulties were greater. Note how hard it would be to make long-term arrangements with suppliers or set up lines of credit. There was a way around these limitations. All of these transactions could be carried out by one or more formally defined contracts such as the stipulatio (the oral question and answer). This contract, however, brought its own disadvantages. Unlike the consensual contract, it required the parties to meet face-to-face. Moreover, stipulatio did not have the same implied warranties, nor was it judged on a good faith basis. Thus, many transactions, even some fairly simple ones, would force the parties to use relatively unpredictable forms, and unpredictability discourages people from doing business at all.
Property Damage. The Aquilian Law of perhaps the third century b.c.e. provided that a property owner should be compensated if someone “wrongly killed his slave or herd animal (whether male or female)” or “caused him loss by burning, breaking, or rending” other property. Over the next two centuries or so, the scope of the law was expanded so that it could cover damage to any property by any means. In the course of this expansion, many significant refinements were also introduced. To establish liability, one had to show the defendant’s malice or negligence. He, in turn, could argue your contributory negligence as a defense. Outside the scope of the Aquilian Law, provisions were made in some cases for preemptive action before damage occurred; for instance, the owner of a dilapidated house could be required to fix it or else offer a guarantee to his neighbor against any damage its collapse might cause. In this area, too, there were gaps in the law. Most notably, there was no way to collect damages for accidental injury to one’s own person, only property.
Ownership. “Ownership” seems like a simple enough idea, but in fact it potentially includes a number of distinct rights: the use of a thing, selling or giving it away, destroying it, preventing others from doing any of these things. Roman law distinguished a number of different rights over property. Ownership proper (dominium) gave broad rights but was potentially difficult to prove. Thus the law also came to protect someone in possession (possessio) of property against most challengers. It was possible (and common) to transfer the use (usufruct) of property (and ownership of its products, if any) to someone else without transferring title. For instance, husbands commonly left usufruct of the family homes to their surviving widows, but they could not sell the property because ownership had been transferred to the children. Individual pieces of land could also bring with them specific rights and responsibilities, for instance, the right to carry water across one farm to another. Once established, these so-called “servitudes” were no longer matters of contract between the two owners personally; they were inherent in the property. In fact, Roman law developed the ability to treat entirely nonphysical rights as property. For instance, one could sell a debt he owned or the right to sue someone in a given matter.
“Crime.”. Roman private law corresponds roughly with what is now called civil law. However, it also covers a number of situations which would be the province of criminal law today. For instance, virtually all forms of theft were treated this way, including burglary, embezzlement, and fraud. Most assaults and batteries were also private offenses. In fact, for much of Roman history, most homicides were private offenses as well. The one early exception was murders within the family. Over time, killings by poisoning and by armed gangs moved from private to public jurisdiction. Finally, perhaps in the first century b.c.e., all homicides became public offenses (with a few exceptions, such as killing one’s own slave, which were not illegal at all).
Bruce W. Frier, A Casebook on the Roman Law of Delict (Atlanta: Scholars, 1989).
Barry Nicholas, An Introduction to Roman Law (Oxford: Clarendon Press, 1962).
Andrew M. Riggsby, Crime and Community in Ciceronian Rome (Austin: University of Texas Press, 1999).
Alan Watson, The Law of Obligations in the Later Roman Republic (Oxford: Clarendon Press, 1965).
Watson, The Law of Property in the Later Roman Republic (Oxford: Clarendon Press, 1968).