At an early age, he abandoned a military career intended by his parents, and became a wandering scholar. Among his teachers was Roscelin the Nominalist, who had a school at Locmenach, near Vannes.

c1101 Quarreling with William, Abelard resolves to start his own school. Finding this not an easy task in Paris, he goes first to Melun, and later to Corbeil. Then he retires to Pallet, due to failing health.

???? returns to Paris to study rhetoric under William of Champeaux. Then back to Melun to teach.

1108 At William’s retirement from teaching, Abelard attempts to secure his chair. He fails, and sets up another own school in Mt. Ste. Genevieve, on the left bank of the Siene, (later the site of the University of Paris).

1113 Finally obtains William’s chair at the Cathedral, and begins teaching rhetoric and dialectic. In order to teach theology, he begins to study theology (scriptural exegesis) under Anselm of Laon. Yet, as in the past, he disagreed with and quarreled with his new teacher.

1117 falls in love with a certain Heloise, a young ward of a certain Canon Fulbert. He becomes a boarder at Fulbert’s house, and begins to tutor Heloise.

1118 This leads to that, and Heloise becomes pregnant. (Though a cleric, Abelard was not sworn to celibacy—however, getting married would mean stepping down as a canon of the Cathedral.) Abelard wanted to marry Heloise, but she demurred, insisting that his philosophical work was too important to abandon. They eventually got married secretly. Though Abelard told the uncle this, to keep his position, he had to tell everyone else they were not married. Eventually the uncle suspects Abelard of lying, and thinking that his niece had been ruined and was going to be abandoned, he hires some thugs to castrate Abelard. Heloise becomes a nun, eventually an abbess, and lived a most exemplary and chaste life thereafter, although she did continue to exchange love letters with Abelard. Abelard entered the Abbey of St. Denis as a monk for a while, but went to back to his teaching after fighting with his fellow monks. Abelard’s son, whom he named "Astrolabe," was adopted by his sister.

1121 Writes the Tractatus de Unitate et Trinitate Divina, on the Trinity. His enemies, including two pupils of Anselm, Alberic and Lotulph, arrange for a council at Soissons, chaired by the Papal Legate, at which to examine his book. Afraid they would lose a debate with him, the Legate is persuaded to condemn the book merely because Abelard failed to subject it to "peer review" before public circulation. The book was accordingly burned, and Abelard was left disgraced, sent to the Abbey of St. Menard, but then back to his own Abbey of St. Denis. There he championed a passage in Bede which questions the tradition that the Abbey’s founder was identical to the author of mystical theological works, as well as one of Paul’s Athenian converts. (Acts 17:34). The Abbot censured him.

1122? So Abelard soon found himself in Paraclete (Le Paraclet), a private chapel he built, giving lectures again and acquiring pupils. People objected to the chapel’s name, as there was no precedent for a chapel dedicated to the Holy Spirit. Abelard replied that (1) he saw nothing wrong with doing so and (2) anyway "Comforter" was not exclusively a name of the Holy Spirit, but also referred to Christ, as Jesus called the Holy Spirit "another Comforter." This did not go over well with the authorities.

1123 writes Sic et Non, consisting of scriptural and patristic passages arranged for and against various theological opinions. In placing the reasons for and against before the student, it exemplified the methodological principle that truth is attained only by a dialectical discussion of apparently contradictory arguments and authorities. Sic et Non developed objective criticisms (dialectics) of the texts as well as techniques to resolve the contradictions and maintain the integrity of the documents, a method later perfected by Alexander of Hales and Thomas Aquinas. It was written initially to respond to Islamic criticisms that Christianity contradicted itself.

1125 At the death of the Abbot of St. Denis, Abelard is absolved from censure by his successor, Suger, who was sympathetic to Abelard. He was offered, and accepted, a position as head of the monastery of Saint-Gildas-de-Rhuys, in Brittany.

1129 However, expecting a lax disciplinarian, the monks there got a very strict one. They tried to poison him, and he retired to Paraclete. He invites Heloise and her nuns to join him there, as their convent had recently lost its lease. He soon returns to lecturing and teaching again.

1130 writes the autobiographical Historia Calamitatum.

1136 Abelard returns to teach at Paris, and revives to some extent his former glory. John of Salisbury is one of his pupils, and possibly Arnold of Brescia (who may have been an associate instead).

1137 Louis VI, King of France, a friend and protector of Abelard, dies. Bernard of Clairvaux, whose reputation in Europe has by now risen to its height, believes not only that Abelard was wrong, but that he was a danger to the faith. Bernard believed that Sic et Non was written to discredit the Fathers. The book on the Trinity had already been condemned, and there was the matter of Heloise. Finally, in a book on the Epistle to the Romans, Expositio in Epistolam ad Romanos, Abelard had developed views of the Atonement that Bernard believed were pernicious—that Christ had come to win men’s hearts by an example of reconciling love, instead of coming to offer satisfaction for sins. [Can’t it be both?] Bernard became convinced that Abelard’s position denied the efficacy of the Atonement. He privately warned Abelard, and roused the bishops against Abelard. Abelard called for a council on the matter.

1141 Abelard was summoned to the Council of Sens. Expecting to debate Bernard on the matter, he found instead that Bernard had met with the Council the night before, and it had already decided to condemn him before he arrived. He was ordered to write no more, and his books were again burned. Abelard refused to speak on his own behalf, choosing instead to appeal the case to Rome. Bernard wrote to Rome, and Abelard only made it to Cluny before Innocent II’s condemnation reached him first. Peter the Venerable, Abbot of the Abbey of Cluny, and one of the few men capable of confronting Bernard, put Abelard under his protection, and appealed his case to Rome.

1142 Peter eventually obtains a migitation of the Sentence from Rome, persuades Abelard to concede the battle, and reconciles him with Bernard. Abelard becomes a monk at Cluny, and then moves to the priory of St. Marcel (a daughterhouse of Cluny). He died there on 21 April 1142, and was buried at Paraclete.