Academic journal article The Review of Metaphysics

Roger Bacon on the Division of Statements into Single/multiple and Simple/composed

Academic journal article The Review of Metaphysics

Roger Bacon on the Division of Statements into Single/multiple and Simple/composed

Article excerpt

IT IS CERTAINLY THE CASE that twelfth- and thirteenth-century treatises on logic represent in great part attempts to re-present the Organon, Aristotle's books on logic, by rearranging the material, adding clarifications, and sometimes breaking new ground as in the case of the treatise on the property of terms. Thus when Roger Bacon is writing his Summulae dialectices around 1252, he is confronted by the problem of what to do with the material on the classification of statements into single or multiple, and simple or composed in chapter 5 of Aristotle's On Interpretation. (1) There, apropos of the two divisions and interspersed among other claims, we read the following: (2)

(A) The first single statement is the affirmation; the next is the negation. The others are single in virtue of a connective.

(B) But why two-footed able to walk animal is one thing (unum) and not many (multa) belongs to a different inquiry--it will not be one because of being said all together.

(C) A single statement is one that either signifies one thing or is single in virtue of a connective. That is multiple (plures) that [signifies] more than one thing, and not just one thing, or if there are no connectives (inconiunctae).

(D) Of these, moreover, the one is a simple statement, for example, something [affirmed] of something or something [denied] of something; the other is conjoined from these, a kind of composed statement.

What is the medieval logician to make of this? While we easily grasp that statements are being divided into single or multiple and simple or composed, we do not proceed much further without being forced to make numerous assumptions. Would not the principal intent of (A) be better read without the second sentence? How is the mystery in (B) to be resolved? Does (C) rule out statements that have no connective from being single? Why are connectives not mentioned with respect to composed statements in (D)? Are such commonplace statement types illustrated by "The Athenian philosopher Plato disputes" simple or composed? Are the more technical ones exemplified by "A man is a mortal rational animal" single or multiple? Even if one adds the guidance presented in chapters 8 and 11 of On Interpretation, such statements cannot be securely classified on the criterion indicated.

Happily, Boethius wrote two commentaries on On Interpretation and, as we shall see, provided his answer to all the questions stated or implied above. (3) Also, since it is through Boethius that the Latin West came to know Aristotle, more often than not the roots of what is found in thirteenth-century treatises on logic can be found in one or more of Boethius's commentaries on the Organon. Is this the case with Bacon's treatment of the types of statements at issue? The purpose of this paper is principally to present and clarify Bacon's divisions of statements as single/multiple and simple/composed, and secondarily to offer an opinion on the sources for his treatment, with special attention directed to Boethius's greater commentary on On Interpretation.


In part 2 of his Summulae dialectices Bacon addresses the issues discussed above, and he begins his presentation with the announcement that "some statements (propositiones) are single, or single in virtue of a connective; others are multiple." (4) The way the divisions are presented are reminiscent of Aristotle (C), and they serve in no way to illuminate what is obscure in On Interpretation.

What criterion is to be used to decide which statements are single and which multiple? The answer comes immediately. "A statement is one to which one response can appropriately be given. A statement is multiple, however, to which more than one response is to be given." (5) So, on Bacon's norm we must take a given statement, reformulate it as a question, and if a simple "yes" or "no"--a single response--can be given, the statement is single; otherwise, multiple. …

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