In an opusculum[377] written shortly after the middle of the eleventh century, Peter Damiani bears unequivocal, if somewhat hostile, witness to the study of law at Ravenna; and it is clear that in his time legal studies were progressing in both France and Italy. It is unsafe to speak more definitely, because of the difficulty in fixing the time and place of certain rather famous pieces of legal literature, which show a marked advance upon the productions to be ascribed with certainty to an earlier time. The reference is to the _Petri exceptiones_ and the _Brachylogus_. The critical questions relating to the former are too complex even to outline here. Both its time and place are in dispute. The ascribed dates range from the third quarter of the eleventh century to the first quarter of the twelfth, a matter of importance, since the opening of the twelfth century is marked by the rise of the Bologna school. As for the place, some scholars still adhere to the south of France, while others look to Pavia or Ravenna. On the whole, the weight of argument seems to favour Italy and a date not far from 1075.[378] The _Petrus_, as it is familiarly called, is drawn from immediately prior and still extant compilations. The compiler wished to give a compendious if not systematic presentation of law as accepted and approved in his time, that is to say, of Roman law somewhat mediaevalized in tone, and with certain extraneous elements from the Lombard codes. The ultimate Roman sources were the Codification of Justinian, and indeed all of it, _Digest_, _Codex_, and _Novels_, the last in the form to which they had been brought in Julian’s _Epitome_. The purpose of the compilation is given in the Prologue,[379] which in substance is as follows: “Since for many divers reasons, on account of the great and manifold difficulties in the laws, even the Doctors of the laws cannot without pains reach a certain opinion, we, taking account of both laws, to wit, the _jus civile_ and the _jus naturale_, unfold the solution of controversies under plain and patent heads. Whatever is found in the laws that is useless, void, or contrary to equity, we trample under our feet. Whatever has been added and surely held to, we set forth in its integral meaning so that nothing may appear unjust or provocative of appeal from thy judgments, Odilo;[380] but all may make for the vigour of justice and the praise of God.”