Abstract

The topic of my dissertation is the treatment of the fallacies of composition and division during the scholastic period , the compounded/divided sense distinction which grew out of that treatment, and the philosophical use to which the distinction was put. For instance, a recognition of these fallacies during the twelfth and thirteenth centuries helped theologians deal with certain problems having to do with foreknowledge and human freedom. In addition, a recognition of the distinction between the compounded and divided senses of propositions allowed medieval logicians after the first quarter of the fourteenth century to get clearer about what might broadly be described as the logic of propositional attitudes. ;In Chapter 1, I briefly summarize and compare theories of composition and division from Peter Abelard to Paul of Pergula . And in Chapters 2 and 3, I examine the treatments of composition and division presented by Lambert of Auxerra , Roger Bacon , and William Ockham . In these treatments, composition and division are viewed in terms of ambiguity. ;By the second quarter of the fourteenth century, one sees the discussion of composition and division move from a concern with ambiguous expressions to a concern with arguments comprised of unambiguous sentences having either the compounded sense or the divided sense in virtue of the sentence's word-order. "Infinitely fast does Socrates run; therefore, Socrates runs infinitely fast" is, according to William Heytesbury , invalid: the premise has the divided sense, and is possibly true; the conclusion has the compounded sense, and is impossible. With Heytesbury there is an increasing emphasis on the compounded/divided sense distinction in connection with verbs signifying mental acts or acts of will: 'know,' 'believe,' 'desire,' 'understand,' etc. In Chapter 4 I explain why these shifts may have occurred in the medieval treatment of composition and division. And in Chapter 5, I consider the effect of Heytesbury's treatment of composition and division on logicians and commentators who come after him. I focus in particular on the work of four fifteenth- through sixteenth-century Italian logicians and their views on epistemic logic