Roger Bacon is especially interested in language as it is used. He realizes that meanings of words can vary according to new impositions, which are given by men. A conventional sign has as its immediate significate something in the outside world. The concept is only a natural sign in the sense of an index, secondarily signified.
In his Summulae dialectices (an early, but mature work, dating c. 1250; later works are his De signis and Compendium studii theologiae) Bacon discusses the properties of terms, of which he names three: supposition, appellation, and copulation (De Libera 1982).
He defines signification: it is the property of a word, or term, on account of itself, and not in relation to any other term. Therefore, he says, a term has signification both inside and outside a proposition.
Supposition is taken in many ways, Roger says. He defines it as a property of a subject term, in as far as it supposits for something else and is subject in a proposition. The term must be actually used in such a proposition.
Supposition is divided into simple and personal. Simple supposition is when a term does not stand for its inferior, but for the word. He takes it more or less in the same way as Peter of Spain, that is, when a term ‘‘man’’ stands for a word itself (man is a word),’’ for man as the worthiest of creatures, for a meaningful word (‘‘man is a noun’’), for man as monosyllabic, and for man as a species (‘‘man is a universal’’).
Personal supposition is when a term stands for its inferiors, such as ‘‘man’’ in ‘‘man runs.’’ This means that ‘‘man’’ supposits for present man, and it implies that the verb ‘‘runs’’ does not exercise influence on the supposition.
Roger presents two views on appellation: some say that a term of itself appellates present things as appellated, past and future things and is common to beings and nonbeings (this gives room for a semantics of empty classes, for instance, of ‘‘Cesar’’ in ‘‘Cesar is a man’’). Others say that a term only applies to present things, and is not common to being and nonbeing, or past, present, and future, according to Aristotle.
Roger notes that the first view is the common one. He investigates and rejects it. This view comes close to the one advocated in the Cum sit nostra, and to what Sherwood labels as the ‘‘improper account.’’ Roger chooses the second view, which is close to Sherwood’s ‘‘proper account.’’ Bacon’s characteristic claim is that a term cannot be common to being and nonbeing. If it stands for things that are not present, this is due to equivocation; then it is ampliated. One might say that he does do justice to predication with regard to empty classes.
Appellation is a property of both subject and predicate terms. He attacks the concept of appellation for all possible referents. This reminds us of the Parisian notion of natural supposition, like we have seen. Due to his strict conception of supposition Bacon does not need restriction. Supposition itself is limited. He opposes conceptions of supposition that include more than present referents, for instance in the way Peter of Spain does.
Lastly, Roger discusses copulation. However, he can be brief, because there is no difficulty, he says. Adjectives, verbs, and adverbs that signify something predicable, have copulation. ‘‘Copulation’’ means that the meaning (res significata) of a term is joined to another term as ‘‘adjacent inclination.’’ It is an adjectival mode of signification, in which something is meant as a property. Copulation has lost its function as a property of terms in this period. Supposition takes over its role. This could be regretted, for logically an adjectival term plays a different role than a substantival term (Jacobi 1992).
World History
