Handbook of the History of Logic: - Fordham University Faculty

The Development of Supposition Theory in the Later 12 th through 14 th Centuries 253
Every A is every B A and B are both distributed by UA. (The first ‘every’
has no effect on B because B is already confused by
the second ‘every’.)
No A is every B A is distributed by NEG; B is distributed by UA but
then made merely confused by NEG.
Some A is every B A is determinate by default and B is distributed by
UA
Some A is not every B A is determinate by DEFAULT; B is distributed by UA
but this is then made to be merely confused according
to Buridan, or determinate according to Ockham.
The question remains how to resolve the difference between Buridan and Ockham
concerning the mode of supposition of a term that is apparently distributed
by two signs. Buridan says that it ends up merely confused, and Ockham says
that it ends up determinate. In the example just given, the right answer in terms
of ascent and descent is that it should be determinate. This is also the case for
another example that Ockham gives: ‘Socrates is not every man’. Unfortunately
the only examples that Buridan gives using ‘not’ are examples that he sees as
special exceptions of his own rule; the result should be determinate when there
are “two negations taken together, relating in the same way to what follows upon
them.” Examples are
Not: no man runs
Socrates does not see no man
The answer he gives here — that the predicate terms have determinate supposition
— agrees with Ockham. So perhaps Ockham is right, and Buridan wrong? No, for
there are other examples mentioned by neither author where a negating negation
applies to a distributed term and makes it merely confused, just as Buridan says;
an example is ‘donkey’ in
Not: some farmer sees every donkey
Both the ‘every’ andthe‘not’ would distribute ‘donkey’ on their own; together
they make it merely confused. (Descent is not possible, but ascent is possible from
‘Not: some farmer sees this donkey’.)
So the rules are not adequately formulated, and it is not at all obvious how to
make them adequate within the theoretical framework given here. I will discuss
this further in the next section, where we consider a revision of the theory in
which distribution comes in two sorts. (Negating one sort produces determinate
supposition, while negating the other sort produces merely confused supposition).
But that is a revision that goes beyond medieval theorizing, and so I will not
consider the issue of causes of modes of supposition further here, except to note
that the rules that were given correctly classify a wide range of cases.