Handbook of the History of Logic: - Fordham University Faculty

The Development of Supposition Theory in the Later 12 th through 14 th Centuries 251
embedding a proposition within a larger context can change the modes of supposition
possessed by its terms, the rules must allow for a sign to change the mode of
supposition that is assigned by another sign. The key to the latter is to formulate
rules that can be applied recursively. For example, the ‘every’ in‘Every donkey is
running’ assigns distributed status to the subject term ‘donkey’; embedding this
within a ‘not’ allows for the ‘not’ to reclassify the mode of supposition of ‘donkey’
as determinate in ‘Not every donkey is running’.
Here are some rules that are common to several authors: 105
DEFAULT: A main term of a proposition has determinate supposition
unless something causes it not to. 106 A particular affirmative sign
adjoined to a term makes it have determinate supposition (or, equivalently,
has no effect).
UA: 107 A universal affirmative sign distributes the term it is adjoined
to and confuses any other main term following it in its scope if that
term is not already confused.
UN: 108 A universal negative sign distributes the term it is adjoined to,
and also distributes any other main term following it and in its scope:
105 Paul of Venice LP II.5 (152-56) has similar rules plus a host of others. For example, the
superlative and comparative constructions distribute their terms; an exceptive expression (as
in ‘every man except Socrates’) makes its term be merely confused, as does a reduplicative
expression (as in ‘Every man as a man’), and terms concerning an act of the mind, such as
‘know’, ‘believe’. Paul speaks here of signs “confounding” terms, and thereby affecting their
mode of supposition. Marsilius TPT 1 (65-71) gives nineteen rules.
106 Buridan SD 4.3.5 (263): “If you ask ‘How do I know when the supposition is determinate?.
I say ...you will know if you see that there is no cause for confusion.”
Ockham SL I.71 (202): “when in a categorical proposition no universal sign distributing the
whole extreme is added to a term, either mediately, or immediately, . . , and when no negation
or any expression equivalent to a negative or a universal sign is added to a common term, that
common term supposits determinately.”
107 Buridan SD 4.3.7.1 (265) says: “a universal affirmative sign distributes the term immediately
following and construed with it.”, and 4.3.8.1 (273): “there are many causes of nondistributive
confusion. The first obtains when the universal affirmative sign confuses a common term following
upon it, but not immediately, as when in the proposition ‘Every man is an animal’ the term
‘animal’ supposits by nondistributive confused supposition.”
Ockham SL I.74 (213) says: “in every universal affirmative and universal negative proposition
that is neither exclusive nor exceptive, the subject has confused and distributive mobile supposition.”
I.73 (211): “where a common term mediately follows an affirmative sign of universality,
it has merely confused supposition.”
108 Buridan SD 4.3.7.2 (269-70) says: “. . . a negative universal sign is nothing else but a word
that implies in itself a negation with a particular affirmative sign. For ‘no-one’ is equivalent to
‘not one’, ‘nothing’ to ‘not something’, ...”. Since Buridan takes the universal negative sign to
be equivalent to negations plus the particular affirmative sign, his views must follow in part from
his view about these two items. These provisions seem to yield the right answers.
Ockham SL 1.74 (213) says: “The first rule is that in every universal affirmative and universal
negative proposition that is neither exclusive nor exceptive, the subject has confused and distributive
mobile supposition.” For the predicate term, Ockham only mentions the first subcase:
“The second rule is that in every such universal negative proposition the predicate stands confusedly
and distributively.” However he probably intends his treatment of negation to apply to
the universal negative sign; see below.