Handbook of the History of Logic: - Fordham University Faculty

508 Simo Knuuttila
and ‘Man is risible’. If the predicate is per se repugnant to the subject,
as in a way excluding the notion of it, it is said to be a proposition in
impossible or remote matter, for example ‘Man is an ass’. If the predicate
is related to the subject in a way midway between these two, being
neither per se repugnant to the subject nor per se in it, the proposition
is said to be in possible or contingent matter. (In Peri herm. I.13, 166
[3], trans. Oesterle, with changes)
Aquinas employs the terms enunciatio and propositio as synonyms and takes them
to mean statement making sentences. For reasons of simplicity, I shall use the term
‘proposition’ for these and related terms in medieval authors. 7
The ancient theory of the matter of propositions was often associated with the
rules of contraries, subcontraries and contradictories in the traditional square of
opposition. While these rules defined how the members of various opposed pairs
were related to truth and falsity, it was thought that they could be further specified
by classifying propositions on the basis of their matter. An interesting feature
in Aquinas’s account of the contingent matter is that universal affirmative and
negative propositions are false and particular affirmative and negative propositions
are true. Comparing this with what is said about propositions in other matters,
modal differences can be characterized as corresponding to a descending order
in the frequency of true cases: the predicate is not truly said of any subject in
impossible matter, it is truly said of some subjects in contingent matter and of all
subjects in necessary matter. Aquinas’s formulations are possibly influenced by
Ammonius’s commentary on Aristotle’s Peri hermenias, translated into Latin by
William of Moerbeke in 1268, but the ancient theory of the matter of propositions
was also known through the works of Boethius and found in many Latin authors
before the translation of Ammonius’s work. 8
7 For medieval terminology, see G. Nuchelmans, Theories of the Proposition. Ancient and
Medieval Conceptions of the Bearers of Truth and Falsity (Amsterdam: North-Holland, 1973).
8 Ammonius, Commentaire sur le Peri hermeneias d’Aristote. Traduction de Guillaume de
Moerbeke, ed. G. Verbeke, Corpus Latinum Commentariorum in Aristotelem Graecorum (Louvain:
Publications Universitaires, Paris: Béatrice-Nauwelaerts, 1961), 168.41-169.57; 175.69-
176.95; 178.27-32; 179.38-43; 180.61-181.82; 199.23-201.63; the Greek text is edited by A. Busse
in Commentaria in Aristotelem Graeca 4.5 (Berlin, 1897). Boethius was acquainted with the
same doctrine which Ammonius explains, though he does not use the same terminology. Ammonius’s
work was not known to Boethius; see R. Sorabji, ‘The Tree Deterministic Arguments
Opposed by Ammonius’, in Ammonius, On Aristotle: On Interpretation 9, trans. D. Blank, with
Boethius, On Aristotle: On Interpretation 9, first and second Commentaries, trans. N. Kretzmann,
with Essays by R. Sorabji, N. Kretzmann and M. Mignucci (London: Duckworth 1998),
3-15. In dealing with the opposition between the pairs of universal and particular propositions,
Boethius distinguishes between predications which are natural (necessary), impossible and neither
natural nor impossible. While universal affirmative and negative contraries of the third case
are both false, the corresponding particular propositions are both true. A universal affirmative
proposition is true in the first case and a universal negative proposition in the second case (In
Periherm. II, 177.18-178.8; see also 303.15-306.13; 325.8-15.) Garland the Computist explains
the same classification, distinguishing between propositions with natural, remote and impossible
matter (Dialectica, ed. L. M. de Rijk, Wijsgerige teksten en studies 3 (Assen: van Gorcum, 1959),
54.21-30; 82.25-30.) In a late eleventh century logical treatise attributed to William of Cham-