163. Summary. -- Paris and Chartres were the centres of all the stirring intellectual tournaments of the twelfth century; Paris especially, whose three famous schools rapidly obtained a monopoly of scientific culture, thus leading up to the creation of the great studium generale towards the end of the century. In the domain of scholasticism (Art. I.) we find numerous forms of extreme realism (§ 1) and of anti-realism (§ 2). Extreme realism was boldly attacked by a critic of no ordinary stamp, Peter Abelard, whose personality and influence deserve to be thrown into due relief (§ 3). At the same time there appeared a tendency to collect and arrange achieved results and produce complete courses of doctrine: the works of two men who collected and summarized the writings of the previous period, John of Salisbury and Alan of Lille (Alanus ab Insulis), are especially noteworthy (§ 4).
Non-scholastic philosophy (Art. III.) is represented mainly by pantheistic sects drawing their inspiration directly from John Scotus Eriugena. A materialistic Epicureanism also appears as animating principle in the heresies of the Cathari and the Albigenses. An intense theological movement (Art. II.) developed at the same time. The compilers of the "Sententiae" and "Summae" arranged and codified the data of dogmatic theology (§ 1); and the first strong current of orthodox medieval mysticism made its appearance (§ 2).