(Peter), one of the most famous doctors of the twelfth century, was born at Palais near Nantzy, in Brittany: he was well learned in divinity, philosophy, and the languages; but was particularly distinguished by his skill in logic, and his fondness for disputations, which led him to travel into several provinces in order to give public proof of his acuteness in that science.

After having baffled many antagonists, he read lectures in divinity with great applause at Paris; where he boarded with a canon whose name was Fulbert, and who had a very beautiful niece named Heloise. The canon ardently wished to see this young lady make a figure among the learned, and Abelard was made her preceptor: but instead of instructing her in the sciences, he taught her to love. Abelard now performed his public functions very coldly, and wrote nothing but amorous verses. Heloise proving with child, Abelard sent her to a sister of his in Brittany, where she was delivered of a son. To soften the canon's anger, he offered to marry Heloise privately; and the old man was better pleased with the proposal than the niece; who, from a singular excess of passion, chose to be Abelard's mistress rather than his wife. She married, however; but used often to protest upon oath that she was single, which provoked the canon to use her ill. Upon this, Abelard sent her to the monastery of Argenteuil; where she put on a religious habit, but did not take the veil. Heloise's relations considering this as a second treachery, hired ruffians, who, forcing into his chamber in the dead of the night, emasculated him. This infamous treatment made him fly to the gloom of a cloister. He assumed the monastic habit in the abbey of St Dennis; but the disorders of that house soon drove him from thence. He was afterwards charged with heresy; but after several persecutions for his religious sentiments, he settled in a solitude in the diocese of Troyes, where he built an oratory, to which he gave the name of the Paraclet. He was afterwards chosen superior of the abbey of Ruis in the diocese of Vannes: when the nuns being expelled from the nunnery in which Heloise had been placed, he gave her his oratory; where she settled with some of her sister nuns, and became their prioress.

Abelard mixed the philosophy of Aristotle with his divinity, and in 1140 was condemned by the council of Rheims and Sens. Pope Innocent II. ordered him to be imprisoned, his books to be burnt, and forbid him ever teaching again. However, he was soon after pardoned, at the solicitation of Peter the Venerable, who received him into his abbey of Clugny, where he led an exemplary life. He died in the priory of Marcellus at Chalons, April 21, 1142, aged sixty-three. His corpse was sent to Heloise, who buried it in the Paraclet. He left several works: the most celebrated of which are are those tender letters that passed between him and Helenice, with the account of their misfortunes prefixed; which have been translated into English, and immortalized by the harmony of Mr Pope's numbers.

ABEL-TREE, or ABELE-TREE, an obsolete name for a species of the poplar. See Populus.