Briefly, what I want to say here is that it would be ideal for any European to know at least spanish and mathematics, and at least an external language (english, chinese), beyond the native language.
I'm saying that the multilingualism in EU is a problem rather than a feature worth supporting, as long as we talk about more than 20 languages. I hope it's obvious for any European that one cannot handle so many languages in a human lifetime.
I think that no more than two common languages are necessary for optimal communication inside EU: mathematics and a common natural language. With the mother tongue, the 3-rd, you grow naturally, so it isn't EU's concern, it's a local issue. So we count 3 languages by now. Obviously you should have the freedom to learn as many languages you like, but that's not EU's issue.
The mathematics and the common language of choice are needed for formal and informal communication, they provide the opening to universality. Quoting Van Cauwelaert in
Un aller simple:
Alors le bonheur, c’est quand je suis allé à l’école. Le bonheur, c’était d’apprendre. Je m’inventais une autre famille, rien qu’à moi, avec les mots et les chiffres que je pouvais changer d’ordre comme je voulais, additionner, conjuguer, soustraire, et tout le monde me comprenait.
The mobility of labor inside EU doesn't need more than these 3 languages: the mathematics, the common language and the native language.
There is also the economic language: the money, but there's no reason of concern here, it's the Euro and it's not a multilingualism issue.
The later we recognize the necessity of a common EU language, the later we'll understand us through
EU (each bigger country will continue to hope that its own native language will predominate, each immigrant moved to, say, Spain, will forget his native language for practical reasons and still won't grasp what his german neighbor is saying, the cultural communication between the EU citizens from different countries will be almost null, as it is today, and this will keep us prey to nationalisms or blanket globalization).
Check the blogs' logs and see if some EU country's blogs are visited by EU neighbor netizens with a comparable frequency with that of the local netizens. Seriously, this says a lot, beyond the natural wish of the translators and publishers to secure a job.
What I understand by mathematics as a common language: that each EU citizen must receive a minimal education allowing him/her to formulate, model and solve problems. The ones with higher studies should graduate, above the high-school level, 1 year of mathematics equivalent with what is taught in technical universities today. My experience makes me suspect that a lot of the graduates of non-technical higher-level schools lack basic discernment, and the basic tools to build it. There is an inflation, which I feel clearly here in Europe, with graduates of "information and communication" "science" who can only mess-up communication and generate noise baptizing it information.
I already wrote my thoughts related to the common natural language (informal) elsewhere on this blog: ideally we should choose Spanish. Briefly, that would allow us to have also numerous external partners in communication (the south-americans) belonging to a "warmer" culture than the current anglo-saxon one.