Medieval Terminist Logic

Origin. 13th-14th century. William of Sherwood, Peter of Spain, Ockham. Properties of terms. Supposition theory. Foundation of medieval semantics.

Models. Terms have properties in propositions. Supposition: what term stands for. Ampliation, restriction, appellation. Context-sensitive reference.

Formalism.

Properties of terms: significatio: meaning (out of context). suppositio: reference (in context). copulatio: for adjectives. appellatio: for connotative terms.

Supposition types: Suppositio divides three ways directly — there is no genus "proper supposition" above them, and the three cannot share the gloss "for what the term signifies," since only the third fits it: Material (materialis): for the word itself ("'homo' has four letters"). Simple (simplex): for the universal or concept ("homo is a species"). Personal (personalis): for the individuals the term signifies ("homo currit"). The propria/impropria distinction is a separate axis: improper supposition covers figurative use — metaphorical, antonomastic, synecdochical — and cuts across the three above rather than containing them.

Personal supposition divisions: Discrete (discreta): singular or demonstrative term (Socrates, this man). Common (communis), which divides three ways by how one descends to singulars: Determinate (determinata): descend to a disjunction of propositions. "Some man runs" → "This man runs or that man runs or …" Merely confused (confusa tantum): descend to a disjunct term inside one proposition. "Every man is an animal" → "Every man is this-animal-or-that-animal-or-…" Confused and distributive (confusa et distributiva): descend to a conjunction of propositions. "Every man runs" → "This man runs and that man runs and …"

Why determinate and merely confused are not both "descent with or": The disjunction sits in different places, and that is the entire distinction. Determinate supposition descends to a disjunction of propositions; merely confused descends to a disjunctive term within a single proposition. From "Every man is an animal" one may not infer "Every man is this animal, or every man is that animal" — the propositional disjunction fails, while the disjunct-term descent holds. Collapsing the two erases the difference between the subject and predicate positions under a universal quantifier, which is exactly what the theory was built to track: in "Omnis homo est animal," 'homo' is confused and distributive while 'animal' is merely confused.

Ampliation: Term's supposition extended beyond present. "A man can be Antichrist." Future individuals included. Modal and temporal contexts.

Restriction: Term's supposition narrowed. Adjectives restrict. "White man" = man who is white. Contextual limitation.

Appellation: Connotative term's secondary reference. "Father" appellates son. Two-place reference.

Symbols.

Term	Origin	Gloss	Role
significatio	Latin	Signification	What a term means outside any proposition
suppositio	Latin	Standing-for	What a term refers to as it occurs in a proposition
copulatio	Latin	Copulation	The corresponding property of adjectival terms
appellatio	Latin	Appellation	The secondary reference of a connotative term
ampliatio	Latin	Ampliation	Widening of supposition into modal or tensed contexts
restrictio	Latin	Restriction	Narrowing of supposition by a modifier
determinata	Latin	Determinate	Descent to a disjunction of propositions
confusa tantum	Latin	Merely confused	Descent to a disjunct term within one proposition
confusa et distributiva	Latin	Confused and distributive	Descent to a conjunction of propositions
discreta	Latin	Discrete	Supposition of a singular or demonstrative term

Metatheory. The theory's central move is the separation of signification, which a term has out of context, from supposition, which it has only as it occurs in a proposition: the semantics is of occurrences, not of words. The modes of common personal supposition are fixed by descent and ascent conditions precise enough to formalize, and they state facts about scope without variables — in "Omnis homo est animal," 'homo' is confused and distributive while 'animal' is merely confused. How much scope theory the modes actually carry has been disputed since Priest and Read (1977) formalized Ockham's account and argued that the definitions as stated do not deliver the intended modes; Spade (1988) argued that by the fourteenth century descent and ascent were no longer doing the work of quantification at all. Ampliation extends supposition into modal and tensed contexts, which is how "a man can be Antichrist" comes out true.

Applies to. Medieval logic. Philosophy of language. Semantics history. Reference theory.

Limitations. The apparatus classifies rather than derives. Descent and ascent sort term occurrences into modes, but nothing licenses passing from one proposition to another, so there is no soundness or completeness claim to be made about the modes at all. They attach to single terms in a single categorical, so quantification nested beyond the subject-predicate pair is handled by extension case by case, which is one reason multiple generality never received a systematic treatment. The disagreements between authors are substantive and not terminological: Burley takes simple supposition to be for a real universal and Ockham for a mental concept, a metaphysical commitment carried by what looks like a semantic classification. And the descent clauses are stated for assertoric categoricals; supposition inside modal and epistemic contexts remained contested.