Handbook of the History of Logic: - Fordham University Faculty

226 Terence Parsons
Personal supposition is determinate when the locution can be expounded
by means of some single thing, which is the case when the word supposits
for some single thing. Therefore in ‘a man is running’ itcanbe
true for anyone running. [Ibid]
He soon adds:
The sentence ‘A man is running’ means that the predicate is in some
one individual, not in many, even though the predicate is in many —
for a sentence sometimes permits this but it does not signify it. [Ibid
V.11 (116)] 80
I assume that the basic account is in the first sentence: supposition is determinate
when the locution “can be expounded by means of some single thing”. This must
not be read as saying that in the sentence the word supposits for only one thing,
as if ‘man’ in‘a man is running’ supposits only for one particular man among
men. Apparently such a view was taken seriously, since Peter of Spain takes
pains to reject it, but in any event William’s view is not of that sort. The added
quote makes this clear: The sentence does not mean that the predicate is not in
many individuals. So we should read ‘the predicate is in some one individual’ as
permitting it to be in more than one. That is, we should read it as ‘the predicate
is at least in some individual’.
Generalizing to propositions of various forms, I suggest that we read the condition
as saying:
A term is determinate in a proposition =df the proposition means that
there is at least one thing x that the term supposits for such that the
proposition is true for x.
To say that the proposition is true for x (with respect to a term) is equivalent to
saying that another proposition is true, namely, the one you get by replacing the
term (and its quantifier sign, if any) by ‘x’.
‘. . . QT ...’ is true for x = ‘...x ...’ is true
where ‘Q’ is any quantifier sign directly governing ‘T ’. Example: The term ‘donkey’
is determinate in ‘Some mammal is a donkey’ because
‘Some mammal is a donkey’ means that there is at least one donkey x
such that ‘Some mammal is x’ is true. 81
This seems to me to be a possible reading of what he says. It also makes sense of
all of his applications. For example, it is easy to check that this makes both terms
80 I interpret the first sentence as “The sentence ‘A man is running’ means that the predicate
is in at least some one individual; it does not mean that the predicate is in many, even though .
..”.
81 Granted, this mixes up use and mention, but I think it is clear enough. We must interpret
‘means that’ loosely, as something like ‘necessarily, is true iff’.