In May a.d. 164 at Immenosus Maior, a gold mining settlement in the province of Dacia, near modern Roşia Montana in Romania, Memmius, son of Asclepius, got a job as a miner. Because he was illiterate his employment contract was written out for him by Flavius Secundinus, probably a slave in the service of the mining contractor, Aurelius Auditor. Memmius dixit se locare et locavit operas s[ua]s, declared himself to be hired out and hired out his services, an evident use of technical language, which has led to the suspicion that there were model contracts to be followed. In return Aurelius, as conductor, contractor, was to pay his wages at the rate of 70 denarii and provide board. There are various terms regarding non-performance on either side or frustration of the contract by inundation of the works by water.

The use of a formal Roman contract by an illiterate workman in this part of the Empire caused some astonishment when this and other Dacian documents came to light in the eighteenth century. It remains a powerful indication of the centrality of law to ordinary Roman life.

Roman law recognised a number of types of contract, modes in which formal legal obligations could be created by individual citizens. Besides sale, which governed the most central commercial dealings for the sustaining of life, hire was the next most important. The Roman term for sale was emptio venditio, buying and selling, which expressed in formal terms the bilateral nature of the deal; for the obligations of the seller, to provide the goods in good condition, differed markedly from the buyer's liability simply to pay the price. Likewise hiring was locatio conductio, the Letting and Hiring of d.P.'s title. But whereas it is simple to tell who is buyer and who seller (at least once we have disposed of Sabinus's suggestion that it might be possible to place barter within the confines of sale) it is not always clear who is letting or hiring what. This is an ambiguity endemic to the English use of these terms–is Bicycles for Hire a statement of intention to hire out or an invitation to take on hire? The Roman use does not admit of ambiguity. In order to protect his interests the locator has a legal remedy in the form of the actio locati, the conductor an actio conducti. Faced with a client who could not tell whether he was locator or conductor–whether he had hired a ship to transport his cargo, in which case he should sue in the actio conducti, or whether he had arranged for the ship to carry his cargo, in which case he had the actio locati–the jurist Labeo opted for a remedy based upon the facts of the case, an actio civilis in factum.

The basic pragmatism underlying the jurists' treatment of their clients' cases which this decision of Labeo reveals is the central theme of d.P.'s treatment of a topic which has not wanted for systematic study in the literature. It was once common to assume that, following the medieval jurists, there was a three-fold division within the contract of hire, one type dealing with the hire of res, things, another type with the hire of labour, as in Memmius' contract, and yet a third covering the letting out of jobs-to-be-done (locatio operis faciendi). Although I once argued that this trichotomy, though not formally stated by the jurists, could be descried in their treatment, it is plain that the situation was more fluid and less formalistic. D.P. accepts a basic division between the hiring of res and the letting of operae but beyond that, following other recent literature, he stresses the need to identify normative situations which underlie the decisions reached by jurists in individual cases. So in the case of locatio rei much depended upon fundamental differences between the hiring out of movables (including slaves and animals) where issues of defects in the goods lent and the imposition of limits upon the permitted use dominate, and the letting of land and houses, where concerns about the differences between rural and urban contexts are paramount. As regards the letting of work and labour d.P. identifies five typical situations. First come those in which the contract concerns the transformation of property of one of the parties: these include the dry-cleaning contracts, where the jurists' concerns focus on the liability of one of the parties to look after the goods of the other (in particular to prevent loss by theft), and contracts for manufactory or construction work, where questions concerning the provision of the materials for the work and issues around approval of the work dominate. Distinct in character are contracts for carriage by land or sea where, aside from important considerations regarding the capacity of slaves acting as their master's agents, the major issues are those involving loss or damage in transit. The discussion in these principal divisions of locatio operae amply justifies the claim that the best understanding of the contract can be gained by concentrating on the fundamental practical issues being addressed by the Roman jurists.

D.P.'s remaining three typical situations of locatio operae have a rather negative cast and are in effect designed to demonstrate that previous categorisations are insecure. So he argues there is no good ground for holding that the so-called artes liberales could not form the basis of a locatio conductio contract, nor that those exercising opprobrious trades such as actors were necessarily excluded. Finally he concludes that the exclusion of hiring out of one's own slaves and freedmen from the contract is an overstatement.

The nature of d.P.'s argument leads him to treat in some detail the actual case situations depicted in the juristic and documentary material. His is not an analysis which seeks to abstract legal concepts from their setting-in-life. On the other hand he is at pains to indicate that it is a legal treatment, not a sociological one. The result is a work which can be profitably read both by those modern Roman lawyers needing to ground their understanding more firmly in the Roman jurists' perspective and by those, not particularly concerned with or versed in the juristic literature, who would nevertheless profit from a more nuanced grasp of the sophistication of the Roman law and its application in the Roman world.