Much of Abelard's philosophy, specifically his philosophy of language, rests on an account of cognition and philosophy of mind. Abelard recognized this dependence. His more famous discussions of universals and propositions each include a brief treatment of cognition and mind as essential groundwork. Around 1125 he wrote the Treatise on Understandings (Tractatus de intellectibus) to present his views in a single work and in a more coherent fashion than he had hitherto undertaken to do. The Treatise's stated purpose is to distinguish and explain the operations of the mind “necessary for the doctrine of sermones” (TI 1), and it reflects Abelard's somewhat ambivalent feelings about the philosophical importance of issues in cognition and philosophy of mind. The issues are important enough to warrant discussion in an independent work, but Abelard did not consider their study to be a philosophical end in itself.

Peter Abelard (1079-1142) is a philosopher and theologian whose reputation has always preceded him. Indeed, to this day he remains among the best-known figures of the entire Middle Ages. Although one can hardly overestimate the value of his intellectual legacy, his reputation owes at least as much to his flamboyant personality and to the sensational details of his biography. Very early on Abelard established his place as one of the most celebrated masters in Paris by challenging - and then defeating - his teachers and rivals in public disputation. In some cases, he literally drove these rivals out of business: he stole their students and set up his own schools (the first when he was only twenty-five) just down the road from them. He aroused the fiercest devotion in students, and the fiercest enmity in rivals. He also inspired the love and devotion of (some would say merely seduced) a seventeen-year-old Heloise. But when Heloise became pregnant and ran away with him to be secretly married, Abelard earned the hatred of her uncle and guardian, Fulbert, who was also the canon of Notre Dame.