Handbook of the History of Logic: - Fordham University Faculty

70 John Marenbon
1999, 101; Forthcoming-a])
Although datings and attributions have been proposed for a number of these
commentaries (see page 77, below), there is little that can be established solidly,
except to place them somewhere in the period c.1090 — c. 1140.
Other composite commentaries that have been considered to belong to the period
include:
P14, which has some relation to P3.
P16, which is thought to be early because it is heavily dependent on
Boethius.
P15, which is made up of extracts from P3 and P15.
(All three commentaries have been transcribed by Yukio Iwakuma.)
4 THE TREATISES AND THEIR FORM
Two long and important logical treatises survive from the earlier part of the twelfth
century: the ‘Dialectica’ by Gerlandus (probably of Besançon) [Gerlandus, 1959],
and the Dialectica of Peter Abelard [Peter Abelard, 1970]. The logical content of
Abelard’s Dialectica is discussed in detail by Ian Wilks in the next chapter. The
comments here are merely about its form and chronology in relation to Gerlandus’s
treatise.
The two Dialecticas do not, as might be expected, make a radical break away
from the commentary form. addressed to his brother Dagobert and said to be
for the education of his nephews [Peter Abelard, 1970,146:23-5], but comparison
with the set of commentaries known as the Logica Ingredientibus (c. 1119) shows
that Abelard is using his lecture material, though perhaps in a considerably earlier
form. He deals, usually section by section, with the material of each of the
textbooks in the curriculum, allowing himself some occasional rearrangements.
In general, he seems to have included more of the discussion that took place in
the lectures here than in the overt commentaries which form the Logica Ingredientibus,
although he sometimes abbreviates it so severely as to make it nearly
incomprehensible. Gerlandus states explicitly in his prologue that his object is
to introduce beginners to the teachings of Aristotle, who tends to be too concise,
and Boethius, who is prolix and difficult to grasp. In the course of his treatise,
Gerlandus goes through each of the ancient textbooks, except for On Division,
writing terse paraphrases followed by sections full of nit-picking questions (what
he calls sophismata). Formally, his work is closest to the literal commentaries
(but with the added sophismata), whereas Abelard’s Dialectica is close formally
to composite commentaries.
The dating of the two Dialecticas is difficult. Abelard’s Dialectica used to be
dated towards the end of his life, after 1140, but recent opinion has put its completion
before 1117, and quite possibly rather earlier than that (see [Mews, 1985,
74-104; De Rijk, 1986,103-8]; Mews is now inclined to accept a date even earlier