The present volume is a detailed and original study of the traditional, doctrine of terms. It can be regarded as an attempt to tackle the question: ,How would the scholastic philosophers have conceived and defended their doctrine bad they bad at their disposal the methods and techniques of contemporary logic and semantics? The answer provided, a systematic reconstruction of a number of important ideas in the history of logic, is both formally illuminating and entirely faithful to the relevant text. The work begins with a general exposition of the doctrine of terns oriented around the basic semantic opposition between significatio and suppositio, analogues of the more familiar notions of sense and reference. As a means of providing a precise and coherent reconstruction of the doctrine the author does not simply provide the predictable translation of the more amenable passages into the language of predicate logic. Rather he develops, on the basis of a careful systematization of the texts themselves, a formalization of his own, incorporating an ontology of substance and accident. The advantages of this approach are revealed in its capacity to provide both a simple reconstruction of syllogistic logic by means of a sequent-calculus and a natural extension of this logic to a theory of supposition. Taking into consideration the categories of substance and accident in place of the more usual apparatus of set and element allows the author to develop a formalized theory of objects in which the two categories are allowed to yield composite objects of various sorts. This makes possible an illuminating application of the theory of concreta and abstracta (square of permutations) both to the theory of ampliatio and appellatio and to modal syllogistics. The work concludes with a sketch of possible further developments and an attempted demonstration of the philosophical relevance of the theory in the light of a critical consideration of the relevant secondary literature. Of interest to: Logicians, philosophers, linguists and historians of these disciplines; medievalists