Abelard: Logic, Semantics and Ontology

"Abelard composed four works on logic: (1) Introductiones Parvulorum, which consists of short glosses on Porphyry Eisagoge and Aristotle Categories and De Interpretatione; (2) Logica Ingredientibus (so called because ingredientibus is the first word of its text), which consists of longer glosses on the texts covered by the previous work together with Boethius' De Differentiis Topicis and was probably written while Abelard was teaching in Paris before 1120; (3) Logica Nostrorum Petitioni (so called because nostrorum petitioni are the first words of its text), which consists of longer glosses on the Eisagoge and may date from the time of his teaching at the hermitage of the Paraclete; (4) Dialectica, which has the form of an independent work about the subjects covered by Boethius' logical writings and Victorinus' treatise De Definitionibus and seems to contain materials from different periods of Abelard's life but probably did not reach its final form until a late date, perhaps the time of his stay at Cluny shortly before his death. Of these the second and the fourth are the most valuable. The Dialectica indeed, though based, like that of Garland, chiefly on the works of Boethius and written with the prolixity which was all too common among medieval authors, is an original composition of great importance for the development of logic. Abelard's mind was the keenest (though not in all respects the most admirable) that had been devoted to the subject for more than a thousand years, and he approached his task with the belief that it was still possible to make discoveries: 'Non enim tanta fuit antiquorum scriptorum perfectio ut non et nostro doctrina indigeat studio, nec tantum in nobis mortalibus scientia potest crescere ut non ultra possit augmentum recipere.' (1) The Dialectica survives in a single manuscript which lacks the opening sections. Excerpts from it were published by Victor Cousin in 1836 in his Ouvrages inédits d' Abelard. But unfortunately the text was not printed in full until 1956, and before that date it was therefore not possible to appreciate the magnitude of Abelard's contribution to the doctrines we regard as characteristically medieval. (...). The text is divided into five tractatus which correspond to groups of Boethius' writings and are called respectively: I Liber Partium, II De Categoricis, III Topica, IV De Hypotheticis, and V De Divisionibus et Definitionibus. Of these the first is subdivided into three volumina dealing with the antepraedicamenta (or quinque voces of Porphyry), the praedicamenta (or categories of Aristotle), and the postpraedicamenta (or questions about meaning raised in the De Interpretatione). (2) But our sole surviving manuscript lacks the whole of the first volume and the opening of the second. This is unfortunate, since the missing part probably contained Abelard's last thoughts about universals. We can be reasonably sure also that it contained an account of the distinction between words of first and words of second imposition, since this was mentioned by Boethius in his commentary on the Categories and is taken for granted later by Abelard."