Handbook of the History of Logic: - Fordham University Faculty

10 John Marenbon
contemporaries, to put down his own version of the views of his chosen authorities.
It was mainly in making this choice that he could exercise his independence, and he
did so by selecting Porphyry above all as the interpreter to follow. The Categories
commentary is close to the surviving shorter, question-and-answer commentary by
Porphyry [Asztalos, 1993], and from Boethius’s own comments about his sources
it is clear that his longer commentary on On Interpretation is by far the best
guide we have now to the contents of Porphyry’s lost commentary on this text.
By choosing Porphyry, rather than any more recent Greek commentator, as his
main guide, Boethius ensured that his presentation of logic would be, by and large,
faithfully Aristotelian, in line with the Different Objects Theory.
Boethius on the ‘Categories’ ([Asztalos, 1993])
Porphyry bore out his general approach to Aristotle with a particular theory about
the subject-matter of the Categories. Interpreters differed as to whether it is about
words or things. Plotinus had taken it to be about things and had been critical of
Aristotle’s discussion, since it said nothing about the Platonic Ideas. Porphyry’s
view, as expressed in his question-and-answer commentary on the work [1887, 90-
1], was that the Categories is about language: it is about words of first imposition,
which signify things, as opposed to words of second imposition (such as ‘noun’ and
‘verb’) that signify other words and are treated in On Interpretation. The things
signified are sensible particulars, since it is to these that people first of all attach
names; and the secondary substances, on Porphyry’s view, are concepts, universals
that are abstracted from the particulars, not the Platonic Ideas. The Categories,
then, and even the assertion in it that (2b5-6) ‘if the primary substances’ (that is,
the sensible particulars) ‘did not exist it would be impossible for any of the other
things to exist’ can be accepted since, in this extension of the Different Objects
Theory, Aristotle is not concerned here with Platonic Ideas, but with universals
that are mental concepts, gained by abstraction, and dependent for their existence
on the primary substances.
Boethius follows Porphyry’s question-and-answer commentary closely and reproduces
his approach to the subject-matter of the Categories. He dramatizes the
theory by attaching it to a story about the origins of human language placed at
the very beginning of his commentary [Boethius, 1891, 159A-C], in which he tells
how, first, names of first imposition, such as ‘horse’, ‘branch’ and ‘two-foot long’
were given their meaning, and then names of second imposition such as ‘verb’ and
‘noun’. Boethius is fairly brief in his comments, because he says that he is writing
for beginners. Whether he ever wrote the second, more advanced commentary
that he promises [Boethius, 1891, 160A-B] is very uncertain: he may well have
been reluctant to produce the type of non-Aristotelian, Iamblichan discussion his
description of it suggests [Marenbon, 2003, 23].
Boethius on ‘On Interpretation’ ([Magee, 1989; Lloyd, 1990, 36-75] a complex discussion
of Porphyrian semantics, which may underlie Boethius’s theories, [Cameron,
Forthcoming; Sharples, Forthcoming])