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Handbook of the History of Logic: - Fordham University Faculty

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The Development <strong>of</strong> Supposition Theory in <strong>the</strong> Later 12 th through 14 th Centuries 267<br />

I have argued above that whe<strong>the</strong>r one descends to a disjunctive or conjunctive<br />

term is a matter <strong>of</strong> grammar, not <strong>of</strong> logic. That may be why <strong>the</strong> addition <strong>of</strong> a<br />

fourth mode in terms <strong>of</strong> descent to a conjunctive term has not yielded an interesting<br />

<strong>the</strong>ory. However, <strong>the</strong>re is a way to add a fourth mode that yields an improved<br />

account. This is achieved not by adding a new mode that classifies terms which<br />

satisfy none <strong>of</strong> <strong>the</strong> conditions for <strong>the</strong> traditional modes, but ra<strong>the</strong>r by subdividing<br />

<strong>the</strong> category <strong>of</strong> distributive supposition. For reasons to be given later, I will call <strong>the</strong><br />

one sort <strong>of</strong> distribution “wide distribution” and <strong>the</strong> o<strong>the</strong>r “narrow distribution”.<br />

Wide distributive supposition is traditional distributive supposition in cases in<br />

which one can ascend back to <strong>the</strong> original proposition from <strong>the</strong> whole conjunction<br />

<strong>of</strong> propositional instances under <strong>the</strong> term. (Not from a single instance, but from<br />

<strong>the</strong> whole conjunction.) Narrow distributive supposition is distribution where one<br />

cannot make this ascent. The four modes would <strong>the</strong>n be:<br />

Determinate:<br />

Descent to a disjunction <strong>of</strong> propositions, and ascent back<br />

from <strong>the</strong> whole disjunction.<br />

Merely confused:<br />

No descent to a disjunction <strong>of</strong> propositions but ascent back<br />

from <strong>the</strong> disjunction.<br />

Wide distributive:<br />

Descent to a conjunction <strong>of</strong> propositions and ascent back<br />

from <strong>the</strong> conjunction.<br />

Narrow Distributive<br />

Descent to a conjunction <strong>of</strong> propositions and no ascent back<br />

from <strong>the</strong> conjunction.<br />

There is precedent for <strong>the</strong> category <strong>of</strong> wide distribution; it is what Paul <strong>of</strong> Venice<br />

[LM:TS 3.11a (95)] 140 proposes for mobile distribution. So far as I know, narrow<br />

distribution has not been proposed. (Immobile distribution generally refers to<br />

cases in which no descent is possible.)<br />

If we think <strong>of</strong> denoting phrases as restricted quantifiers, <strong>the</strong>n this is equivalent<br />

to saying: 141<br />

140 “Distributive general reference is tw<strong>of</strong>old because some is mobile, some immobile. Distributive<br />

mobile general reference is <strong>the</strong> meaning <strong>of</strong> a common term beneath which one can infer to<br />

all <strong>of</strong> its singulars conjunctively on <strong>the</strong> condition <strong>of</strong> a proper middle and, conversely, with <strong>the</strong><br />

same middle. Thus this follows: ‘This animal runs and this animal runs and thus <strong>of</strong> each individual<br />

and <strong>the</strong>se are all animals; <strong>the</strong>refore, every animal runs’.” He correctly includes subjects<br />

<strong>of</strong> universal affirmatives, and both subjects and predicates <strong>of</strong> universal negatives as having this<br />

mode <strong>of</strong> supposition.<br />

141 I am speaking loosely here when I refer to quantifier rules such as “Existential Instantiation”.<br />

Such rules can indeed be invoked, but only if <strong>the</strong> syntax <strong>of</strong> <strong>the</strong> language is enhanced with<br />

variables, etc.

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