The expansion in areas of human interrelation (mainly economic and technological), is giving rise to an important phenomenon of the bilingualization or functional polyglotization of many individuals. Political action and representations and discourses on language diversity are therefore primordial. One of the first aspects we need to study with world authorities is how to overcome, through discourse, the dichotomies that restrict us, and promote the search for new principles and ways of looking at situations of language contact. As regards the traditional criteria for the organisation of plurilingualism, for example, I believe that we may need to look beyond the principles of 'territoriality' and 'personality' for the more complex situations that so require. Despite their obvious advantages, both principles tend to presuppose that individuals are monolingual and cannot, in principle, resolve the problem of intercommunication. How then can principles such as these resolve the construction of a European sociocultural space in practice? How are we to understand each other, setting aside simple, formal institutions with multiple translation systems, if we all want to remain functionally monolingual? How would the application of a principle of 'personality' be possible for so many languages in such a widespace? We may well have to look elsewhere for the answer. I suggest, therefore, that the search focuses on the study of the application of the principle called 'subsidiarity' (already present in European nomenclature) in the field of linguistic communication. We could adapt this political and administrative principle into a language policy principle that, generally-speaking, establishes the criteria that "whatever a 'local' language can do, a 'global' language should not". That is to say, we would allow – and promote – the effective, mass knowledge of other languages, giving functional pre-eminence where possible to the language of each historically-constructed linguistic group. So-called'foreign' languages would be used for external contact (which would occur increasingly more often) but local, everyday functions would be clearly allocated to the own languages of each linguistic group. After years of thinking in terms of ‘or’, we now need to explore the linguistic organization of mankind in terms of ‘and’, i.e. from the point of view of complexity– without excluding either objective. We must ask ourselves about how precisely we canmake both possible: the maintenance and development of the various languages and, at the same time, the necessary intercommunication.