While I understand the gist of what you're saying, there's quite a large body of work in French, Italian etc. that directly contradicts your point. Unless you c

While I understand the gist of what you're saying, there's quite a large body of work in French, Italian etc. that directly contradicts your point. Unless you consider state administration and literature to be « informal ». Most things switched to vernacular by the 14th c., and writing wasn't at all exclusive to the clergy. There was a healthy class of notary public, magistrates etc. among the laity of the urban societies of the later Middle Ages. The rise of written vernacular was concurrent to the rise of the middle class.