Abelard's Commentary on Porphyry

Abelard was a rival of William O'Champo, master of the school at Notre-Dame. The two first encountered one another in Paris right around the year 1100. In an autobiographical work, Abelard tells us himself how he refuted William's realist understanding of universals. If we consider humanity just by itself, we see that it is universal in nature and in all humans.