‘Every age should be the mistress of its own law.’[10]

Altmeister Maitland learned this lesson from Germany, and Peter Stein, who has illuminated the history of legal developments in many lands and at different periods, has passed that same lesson on to us.^[11] The message from Cambridge is surely correct - provided, of course, the new mistress does not too readily believe that in her salad days all her judgments are better than the mature reflections of her predecessors.

Happily the playthings of Romanists do not wear out quickly, and the Roman rules are studied to this day. But when the original doctrine is discarded in this way, the texts can be particularly difficult to interpret. Since we have all been brought up in a system with different assumptions, we tend to look at the texts through spectacles which are coloured by those assumptions. Even the most conscientious legal historian will find it hard to see a problem as the Roman jurists would have seen it. I have chosen to discuss a text on the lex Aquilia whose interpretation illustrates these problems in an acute form.

D.9.2.23.4 (Ulpian, 18 ad edictum). Sed et si servus qui magnas fraudes in meis rationibus commiserat fuerit occisus, de quo quaestionem habere destinaveram, ut fraudium participes eruerentur, rectissime Labeo scribit tanti aestimandum, quanti mea intererat fraudes servi per eum commissas detegi, non quanti noxa eius servi valeat.

On the other hand, in the case of killing a slave who had committed great embezzlements in running my affairs and whom I had resolved to examine by torture in order to drag out the names of his accomplices in dishonesty, Labeo writes very rightly that he must be valued according to my interest in detecting the frauds he had committed and not according to the value of the harm he had done.^[13]

Scholars^[14] agree that the opinion of Labeo in this text is an early illustration of the process by which the measure of damages under chapter 1 was expanded beyond the value of the slave himself to include the loss suffered by the individual plaintiff as a result of the slave’s death. But, if that much is agreed, modem writers remain divided about the exact scope of Labeo’s decision. We begin by looking at their views.