Handbook of the History of Logic: - Fordham University Faculty

282 Henrik Lagerlund
and references to Roger Bacon’s Summulae dialectices and Lambert of Auxerre’s
Logica. This will give the reader a good sense of what logic was thought to be in
the mid-thirteenth century.
At the beginning of the thirteenth century there were two theories that logicians
thought about as not deriving from Aristotle. The first was what came to be
called the properties of terms and the other was the discussion of syncategorematic
terms. Under the heading ‘properties of terms’ the logicians of the time dealt with
signification and supposition of so called categorematic terms. This theory worked
its way into the textbooks very early. The treatment of syncategorematic terms
developed into a separate literary genre and both Peter of Spain and William of
Sherwood wrote treatises on Syncategoreumata. I have included a discussion of
the content of these works as well.
I have naturally included references to the works I discuss and also to the most
important secondary literature, but I have not quoted in original language and I
have tried to explain as many technical terms as possible. I have also not used any
notation from contemporary symbolic logic, since I do not think it is helpful for
understanding medieval logic. In my view it raises more questions than it answers.
The organisation of the sections in this chapter is chronological, which means
that I will begin with Arabic logic, since most of it was translated in the midtwelfth
century, and then move on to my treatment of the commentary tradition.
I will end with the discussion of the so called textbook authors, which might seem a
little backwards since they are usually much less advanced than the commentaries.
If someone only wants a quick introduction to thirteenth century logic, he or she
can jump directly to that section below, since I am not presupposing the previous
discussion.
Even though this chapter is fairly long, I have only been able to scratch the
surface of the rich debates about logic and language in the late twelfth and early
thirteenth centuries. I hope this can serve as an introduction and appetiser to
more independent and deep studies of the primary texts themselves.
2 BACKGROUND
Medieval logicians divided logic into: the old logic (logica vetus), the new logic
(logica nova), ancient logic (logica antiqua), and modern logic (logica moderna). 3
(2.1) Logica vetus: Before the first decades of the twelfth century medieval
thinkers in the Western tradition only had access to the Categores and De
interpretatione. These works together with Porphyry’s Isagoge, which is an
introduction to the Categories, and Boethius’ commentaries on these three
works as well as his logical monographs 4 were called logica vetus (or ars
3 For an outline of this see also [de Rijk, 1962, 14–5].
4 Boethius’ logical monographs are: De syllogismis categoricis, De syllogismis hypoteticis, De
divisione, andDe differentiis topocis. See [Jacobi, 1988].