Why should we engage in language universals research and language typology? What do we want to explain? It is a fact that, although languages differ significantly and considerably. indeed, no one would deny, that they have something in common; how else could they be labelled 'language'? - There is obviously unity among them, no matter how vaguely felt and for what reasons: Scientific, practical, moral, etc. Neither diversity per se nor unity per se is what we want to explain. There is no reason whatsoever to consider either one of them as primary, and the other as derived. What we do want to explain is "equivalence in difference" – cf. our motto – which manifests itself, among others, in the translatability from one language to another, the learnability of any language, language change – which all presuppose that speakers intuitively find their way from diversity to unity. This is a highly salient property which deserves to be brought into our consciousness. Generally then, our basic goal is to explain the way in which language-specific facts are connected with a unitarian concept of language – "die Sprache" – "le langage".