0.1 The idea of universal grammar has a long history which provides us with a suitable context to define its content. Such a historical approach will be adopted in the last section in which special attention is paid to the contributions mentioned in the title of this essay. First, however, the notion of universal grammar will be defined with a reference to particular grammars, the latter notion having been known from experience (we roughly know what we mean when speaking of grammars of English, German, Latin, the language of predicate logic, etc.).