With the Hellenistic age began jurisprudence, the _science_ of law, the systematic comprehension of the law which men actually apply. Since legal thought presupposes a substance of political and economic relations, in the same way as mathematical thought presupposes physical and technical elements of knowledge,[82] Rome very soon became _the home of Classical jurisprudence_. Similarly in the Mexican world it was the conquering Aztecs whose academies (e.g., Tezcuco) made law the chief subject of study. Classical jurisprudence was the Roman’s science, and his only one. At the very moment when the creative mathematic closes off with Archimedes, juristic literature begins with Ælius’s _Tripertita_, a commentary on the Twelve (198 B.C.).[83] The first systematic private law was written by M. Scævola about 100. The genuine maturity of Classical law is in the two centuries 200-0--although we to-day, with quaint perversity, apply the time to a period which was really that of Early Arabian law. And from the relics of these two literatures we can measure the greatness of the gap that separates the thought of two Cultures. The Romans treat only of cases and their classification; they never analyse a basic idea such as, for instance, judicial error. They distinguish carefully the sorts of contracts, but they have no conception of Contract as an idea, or of any theories as to invalidity or unsoundness. “Taking everything into account,” says Lenel,[84] “it is clear that the Romans cannot possibly be regarded as exemplars of scientific method.” The last phase is that of the schools of the Sabiniani and Proculiani (Augustus to about 160 A.D.). They are scientific schools like the philosophical schools in Athens, and in them, possibly, the expiring stages of the conflict between the senatorial and the tribunician (Cæsarian) conceptions of law were fought, for amongst the best of the Sabiniani were two descendants of Cæsar’s slayers and one of the Proculiani was picked upon by Trajan as his potential successor. While the method was to all intents and purposes settled and concluded, the practical fusion of the citizen’s statute-law (_jus civile_) and the prætor’s edict (_jus honorarium_) was carried out here. The last landmark of Classical jurisprudence, so far as we know, was the _Institutes_ of Gaius (about 161).