This book reviews the history of the interface between morpho-syntax and phonology roughly
since World War II. Structuralist and generative interface thinking is presented
chronologically but also theory by theory from the point of view of a historically interested
observer who however in the last third of the book distills lessons in order to assess
present-day interface theories and to establish a catalogue of properties that a correct
interface theory should or must not have. The book also introduces modularity the rationalist
theory of the (human) cognitive system that underlies the generative approach to language from
a Cognitive Science perspective. Modularity is used as a referee for interface theories in the
book. Finally the book locates the interface debate in the landscape of current minimalist
syntax and phase theory and fosters intermodular argumentation: how can we use properties of
morpho-syntactic theory in order to argue for or against competing theoriesof phonology (and
vice-versa)?