The late medieval period is widely acknowledged as one of the most salient moments of the history of logic and semantics. It not only considered logic as a sine qua non condition for scientific knowledge, it also begot highly sophisticated theories about both argumentation and language. The last fifty years of increasingly intense research have brought about an ever more detailed knowledge of these theories. And yet, the questions as to what kind of logic is medieval logic, whether and to what extent it corresponds to our conception of logic, and, even, what the nature of its object was, remain challenging. That it has a formal character is widely accepted; and its semantic components display remarkable affinities with contemporary ones. But is it formal in the way modern logic is - or believes it is? Medieval logic does not really make recourse to symbolisms, after all, and the fact that the idea of formal validity might have been born in the twelfth century does not mean that developing formal approaches was an aim of medieval logicians. And what is its semantics a semantics of? Medieval logicians use Latin to deal with Latin constructions, but do these constructions belong to natural language or are they regimented to the point of forming some sort of ideal language?
The twenty-five papers gathered in this volume deal with these issues, thus allowing to reassess the broader questions of the formal character and formalising ambitions of medieval logic, as well as that of the natural character of the language in (and on) which it operated: in other words, they address the question of the nature, object and purpose of medieval logic.