Summary

The paper sketches the story of the original medieval doctrine, which flourished in the Late Middle ages. The theory of supposition was named after its central notion suppositio. The theory basically deals with the reference of terms within the context of their occurrences. Medieval logicians distinguished several properties of terms, which they considered to be relevant when analyzing meaning and truth of propositions. The paper gives the basic definitions of the supposition and its ramifications: imposition, appellation, signification, restriction, ampliation.

The theory originated in the second half of XII c. Its development was influenced by the medieval doctrines of fallacies, grammatical and language-theoretical research (Priscian, Peter Helyas) and the doctrines of linguistic and logical background of theological contexts (Porretani, Nominales).

According to the texts, which are available to the modern reader, during the whole its career (XII-XV cc) the theory of terms was widely used as the most simple and elegant method of detecting some kinds of fallacies and solving sophisms. On the other hand it was aimed to fill up the ontological "thing-sign" gap. The paper also points to the problem of modern evaluation of the theory of supposition and argues that it is the original medieval doctrine that cannot be adequately formalized in terms of modern formal logic. The paper describes several modern hypotheses of interpreting the theory, groups them under at least four main trends and gives brief accounts of each of the four.

The paper particularly comments on some specific features of the development of the theory. The structure of the theory itself is a classification of types of supposition and other properties of terms with some identification and application rules. It remained almost unchangeable while the approaches to the theory as well as its place and its role underwent an evolution, which reflected the basic philosophical convictions in what concerns the problem of universals, philosophical psychology and the doctrine of mental language and etc.); After almost a century of stagnation (XIII) the theory has revived in W.Ockham mainly due to his conceptualism and his doctrine of mental language. W.Ockham's approach to supposition enjoys the central place in the paper. His definitions of the types of suppositions and of the kinds of signification are given and are thoroughly commented on. The paper considers Ockham's rules of identification and use; the rules are analyzed according to Ockham's original examples of solving sophisms. The paper also points to his purports to define the identification rules as formal ones, in spite of their close relationship with the doctrines of the first\second intentions and the theory of impositions of names (terms).