The first known occurrence of the term in its Latin form ("Respublica literaria") is in a letter by Francesco Barbaro to Poggio Bracciolini dated July 6, 1417; it was used increasingly in the 16th and 17th, so that by the end of that century it featured in the titles of several important journals. Currently, the consensus is that Pierre Bayle first translated the term in his journal "Nouvelles de la République des Lettres" in 1684. But there are some historians who disagree and some have gone so far as to say that its origin dates back to Plato's "Republic". Part of the difficulty in determining its origin is that, unlike an academy or literary society, it existed only in the minds of its members.