Special Issue on Multimodal Logics: A Preface

Abstract

It is a fact that investigations of multimodality are currently an advanced area of inquiry within the immense field of intensional logic. A remarkable aspect of this growth is that important branches of modal logic have been shown to be reconstructable as branches of multimodal logic. To mention only one example, binary conditional operators, as Lennart Aqvist convincingly showed in the 1970s, may be defined inside a logic having two or more primitive monadic modal operators, so that conditional logic may in principle be reconstructed as a branch of multimodal logic. Terms such as “multimodal logic” or “polymodal logic” have become part of common usage since the 1980s, but the history of multimodal logic is longer than what the history of these terms suggests. In 1970, in his “Advice on Modal Logico, Dana Scott wrote: