The Collaborative International Dictionary
Republic \Re*pub"lic\ (r?-p?b"l?k), n. [F. r['e]publique, L. respublica commonwealth; res a thing, an affair + publicus, publica, public. See Real, a., and Public.]
Common weal. [Obs.]
--B. Jonson.-
A state in which the sovereign power resides in the whole body of the people, and is exercised by representatives elected by them; a commonwealth. Cf. Democracy, 2.
Note: In some ancient states called republics the sovereign power was exercised by an hereditary aristocracy or a privileged few, constituting a government now distinctively called an aristocracy. In some there was a division of authority between an aristocracy and the whole body of the people except slaves. No existing republic recognizes an exclusive privilege of any class to govern, or tolerates the institution of slavery.
Republic of letters, The collective body of literary or learned men.
Wikipedia
The Republic of Letters (Respublica literaria) is the long-distance intellectual community in the late 17th and 18th centuries in Europe and America. It fostered communication among the intellectuals of the Age of Enlightenment, or " philosophes" as they were called in France. The Republic of Letters emerged in the 17th century as a self-proclaimed community of scholars and literary figures that stretched across national boundaries but respected differences in language and culture. These communities that transcended national boundaries formed the basis of a metaphysical Republic. Because of societal constraints on women, the Republic of Letters consisted mostly of men. As such, many scholars use "Republic of Letters" and " men of letters" interchangeably.
The circulation of handwritten letters was necessary for its function because it enabled intellectuals to correspond with each other from great distances. All citizens of the 17th-century Republic of Letters corresponded by letter, exchanged published papers and pamphlets, and considered it their duty to bring others into the Republic through the expansion of correspondence.
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.
Historians are presently debating the importance of the Republic of Letters in influencing the Enlightenment. Today, most Anglo-American historians, whatever their point of entry to debate, occupy a common ground: the Republic of Letters and the Enlightenment were distinct.