Handbook of the History of Logic: - Fordham University Faculty

The Development of Supposition Theory in the Later 12 th through 14 th Centuries 261
Ockham and Buridan agree on this definition. 120 Burley gives the same account
but omits the ascent condition. 121 I assume that this is an oversight — if the
ascent condition were omitted then the definition would not cohere with many
paradigm cases. For example, ‘donkey’ in ‘Every donkey is running’ would be
determinate because one can descend to a disjunction. The notion of determinate
supposition was quite stable from author to author.
8.9.2 Distributive Supposition122 Our definition of distributive supposition has been:
A term F has distributive supposition in a proposition P if and only if
[Descent]: you may descend under F to a conjunction of
propositional instances of all the F s, and
[Ascent]: from any one instance you may not ascend back to
the original proposition P .
This is essentially Ockham’s definition. 123 Buridan and others omit the condition
that prohibits ascent from an instance. 124 I am not certain how important this is.
That is because the prohibition of ascent may be redundant. For there to be a case
in which one can descend to a conjunction, and then ascend from any instance,
one would need a proposition and a common term in it such that the proposition
is logically equivalent to any of its descended forms. I suspect that it is impossible
120 Albert of Saxony (SL II.4) gives an equivalent account: “Determinate supposition is the
use of a general term for each of the things it signifies by its imposition, or which it signifies
naturally (if it is a mental term), in such manner that a descent to its singulars can be effected
by a disjunctive proposition. In this sentence, ‘A man runs’, the term ‘man’ has determinate
supposition, because the term ‘man’ in this sentence stands, disjunctively, for everything which
it signifies by its imposition. For it is sufficient, for the truth of the proposition ‘A man runs’,
that this disjunctive proposition be true: ‘This man runs, or that man runs’, and so on for all
singulars.” Since any disjunct entails the disjunction, this last sentence gives the ascent condition.
Paul of Venice LM 3.8 (89) gives a vaguer account that is the same if one takes for granted that
he is discussing disjunctions: “Determinate supposition is the meaning of a term in a proposition
beneath which one can infer all of its referents and conversely on the condition of a proper
middle.”
121 Paul of Venice LP 2.4 (149) gives the same account as Burley.
122 Buridan’s account omits the non-ascent condition. Ockham includes additional provisions
for immobile distribution. Burley does not define distributive supposition; instead he defines two
kinds of distributive supposition. This is discussed below.
123 See note 101
124 See note 101 for Buridan’s view. Other authors than Buridan gave equivalent definitions.
Albert of Saxony SL II.4 states: “Confused and distributive supposition is the interpretation of
a spoken or written term, in conjunctive manner, for each thing which it is instituted to signify;
or it is the interpretation of a mental term for each thing which it signifies naturally—-such that
a descent to the singulars, for which it stands, can be made in conjunctive manner, by reason of
that supposition.” This account was also given by at least two anonymous early authors (in [De
Rijk, 1967]): [UD] “Confused and distributive is when of necessity a descent is made to every
inferior.” and [CSN] “Confused and distributive supposition is when a common term supposits
for its inferiors and it is possible to make a descent under it to any appellated content under the
distributive term.”.