Handbook of the History of Logic: - Fordham University Faculty

The Development of Supposition Theory in the Later 12 th through 14 th Centuries 265
every donkey an animal is ⇒
not some donkey not an animal is ⇒
not some donkey every animal isn’t
The other modes of supposition are preserved through these equipollences, and
merely confused supposition is also preserved on all accounts other than Ockham’s.
A related example concerns the predicate term in ‘No animal is every man’. Marilyn
Adams 134 points out that it does not have either determinate or distributive
supposition, and on Ockham’s account it does not have merely confused supposition
either, because one cannot descend to a proposition with a disjunctive term.
From:
No animal is every man
we may not infer
No animal is this man or that man or . . . 135
John Dorp 136 proposes that in order to tell what mode of supposition a term has
we should first move the verb to the end, and then move any negation to the
right of all of the verbs. (Applications of Sherwood’s equipollences given in 1.7
will do this.) This needs to be done before applying Ockham’s test. Then, every
term in the categorical will end up with ‘every’ or‘some’ as its quantifier sign.
If it is preceded by ‘every it has distributive supposition. If it is preceded by
’some’, then either it will satisfy the conditions for determinate supposition, or
not. If it does not, it may be paraphrased by a disjunctive term. This renders
Ockham’s test for merely confused supposition accurate. However, it may also
render it redundant, for it is not clear that there are any occurrences of terms that
are neither determinate nor distributed, and that satisfy the ascent condition for
merely confused supposition, but that are prohibited from having merely confused
supposition because of failure of the disjunct predicate option.
Some authors 137 proposed a fourth mode, which is possessed by any term which
is not determinate or distributive or merely confused. A term has this mode of
supposition if one may descend to a conjunctive term. In the example just given,
this is possible; from:
No animal is every man
we may infer
No animal is this man and that man and . . .
134 Adams 1987, 366-67.
135 Buridan SD 4.3.8.2 (277) says that ‘donkey’ is merely confused in ‘No man sees every
donkey’. But ‘every donkey’ cannot be paraphrased here as ‘this donkey or that donkey or . . . ’.
136 Cited in [Karger, 1993, pp. 418–20].
137 Cf. [Read, 1991, 77-82].