As the preparatory work for the German Civil Code began, the direction of Roman law studies changed. Roman law, it has been said, was handed over to the historians. At first in Germany, and later in Italy and elsewhere, scholars turned to the work begun by the Humanists three centuries before, of rediscovering the classical law. And once again the defects of the Corpus Iuris appeared as virtues.
The ‘inscriptions’ of the fragments in the Digest made it possible partially to reconstruct some of the main works of the later classical jurists; and from the reconstruction of the commentaries on the Edict it was possible to recover the order and in part the substance of the Edict itself. Similarly, from the constitutions in the Code some developments of the post-classical law could be traced.
In this respect there stood the problem of interpolations. Some of the more obvious had been noted by the Humanists, but now the work began in earnest, with all the equipment and ingenuity of modern scholarship. The methods used were sometimes simple. Very occasionally a text in the Digest has also survived independently—in the Institutes of Gaius for example; or the same text occurs twice in the Digest itself, in different versions.
More commonly we can tell that the law stated in a particular text is not classical because it represents an innovation made by a surviving constitution of a later date, or because the law is stated otherwise by Gaius or another classical source. Where these criteria are lacking, more complex and less reliable methods have to be used. The language, the grammar, or the logical structure of a passage may reveal the hand of the compiler, or the same author may be credited with incompatible views in different fragments drawn from the same work.
Methods such as these—and there are many variants—are obviously capable of abuse, and certainly in the third and fourth decades of this century the hunt for interpolations led to many exaggerated claims, but a great deal which is of indisputable validity remains, and our knowledge of the classical law has been transformed. Indeed it has become plain that we know in many ways less about the law of Justinian and of the post-classical period than we do about the classical law.
For whereas previously it had been assumed that the texts reached the compilers substantially unaltered, and therefore that if the interpolations could be detected we should know both the classical law and the law of Justinian, it is now realized that the truth must be a great deal more complex. On the one hand it has become clear that the texts which survive independently of Justinian were edited and altered in post- classical times, and that it is therefore likely that at least some of the texts which reached Justinian’s compilers had been treated similarly.
The search for these pre-Justinianean interpolations has begun. On the other hand, the divergence between the ‘vulgar law’ and the imperial law has been to some extent detected and described. There remains the further problem, as yet little investigated, of the extent to which the law of Justinian, in so far as we can see it in his constitutions and in those interpolations which can be attributed to his compilers, represents the law which was actually applied in the practice of his own time.