Handbook of the History of Logic: - Fordham University Faculty

112 Ian Wilks
bial construal of the proposition is available in this context as well, under which
Socrates is taken as the subject, and running is predicated under the mode of
necessity. Perhaps the idea behind this point is that the adverbial interpretation
is the basic one anyway, so it is natural to read it even into contexts where it is
not explicitly invoked.
The result of this interpretative leniency is to provide alternate construals for
standard modal propositions. This ends up being an immensely important point,
since the distinction between these two syntactic construals is suggestive of the
pervasive semantic distinction between de re readings of modals and de sensu
readings, the former associated with an adverbial construal of the mode, the latter
with a nominal construal. 56 The distinction is introduced by Abelard through a
familiar Aristotelian example: “It is possible for the standing man to sit” [Abelard,
1958, p. 13 (15–16); Abelard, 2006, 12.18; Aristotle, 1984b, p. 280 (166b24–26)].
The analysis of the example shows that the de re and de sensu readings are so
different that the same proposition true on one can be false on the other.
(i) The de sensu reading takes the syntax of the nominal mode as it stands,
and interprets the mode (“possible”) as the predicate. The subject is then the
dictum “for a standing man to sit” or “that a standing man sits” — and this
is what is said to be possible. Note that the resulting syntax puts “standing”
and “sitting” in combination as referring to the same thing. But the combination
is impossible, since nothing can be sitting and standing at once. So on the de
sensu reading the proposition is false. (ii) The de re reading takes the syntax of
the mode non-literally and interprets the mode as adverbial. This reading puts
“standing man” as the subject. “Sits” is what is predicated, with the predication
coming under the adverbial modification of “possibly.” The effect of this reading
is to partition “standing” from “sits.” Instead of putting both in the subject term
(“that a standing man sits”), one is put in the subject term (“a standing man”),
and the other, under modal qualification, is put in the predicate term (“possibly
sits”). Because of this partition the de re reading avoids referring to its subject
as both standing and sitting; it just refers to it as standing, and says of it that it
is possibly sitting. The resulting predication, far from being self-contradicting, is
perfectly capable of being true. In fact it is capable of being true in more than
one way. It can be true when the mode is interpreted diachronically to mean that
the standing man can sit at some time after the time at which he is standing.
Or it can be true when the mode is interpreted synchronically to mean that the
standing man is now sitting in some possible world co-relative to ours. 57 However
56 In Abelard’s hands, however, the association is not automatic. Paul Thom notes that “the de
sensu/de rebus distinction has a different fundamentum divisionis from the compound/divided
distinction” [Thom, 2003, p. 46] (the latter being equivalent to the nominal mode/adverbial
mode distinction). See also [Knuuttila, 1993, pp. 85-87].
57 Whether Abelard’s primary understanding of the modes is diachronic or synchronic has been
a matter of some debate. We find an argument for the former position in [Knuuttila, 1981, pp.
178-87], and for the latter in [Weidemann, 1981]. Knuuttila replies and refines his position
in [Knuuttila, 1993, pp. 93–94]: “Even though one cannot claim that Abelard’s modal thinking
was systematically based on a model of counterfactual synchronic alternatives, it probably