@AriaAber: "mysticism is the anti-babel. it is a search for a common language, after language has been shattered. it is the invention of a 'language of angels', because that of man has been disseminated." ––michel de certeau
Peter Kaminski found the source and provided a better translation here:
It's from La Fable mystique:
La mystique, c'est l'anti-Babel; c'est la quête d'un parler commun après sa fracture, l'invention d'une langue "de Dieu" ou "des anges" qui pallie la dissémination des langues humaines.
Another translation might be:
Mysticism, it is the anti-Babel; it is the quest for a common language after its fracture, the invention of a language "of God" or "of angels" which palliates the dissemination of human languages.