Sean O'Faolain was the most important Irish public intellectual in the decades following the achievement of independence in 1922. In founding the monthly periodical The Bell in 1940, he created the forum for debate and critical analysis of the State's policies and the broader national culture at a time in which people were asked to pay unquestioning allegiance to the abiding conservative, Catholic, and nationalist ethos. O'Faolain's regular editorials, coupled with a slew of histories and biographies that he published in the 1930s and 1940s, consistently called into question the essentialist and primordialist notions of Irish identity that was furthered by politicians, community leaders, cultural groups, and ethnic propagandists who claimed that the Irish people were an ancient and pure race. The apogee of these writings is his influential historical character study The Irish (1947), a work that – fittingly for a writer who railed against the detriment caused by the persistent insularity of the Irish nation – had been inspired by continental historians, notably Charles Seignobos and his landmark Histoire sincère de la Nation française (1937). Here and throughout his oeuvre, O'Faolain argued that Ireland benefitted, became enlightened, and was a beacon of ideas and culture to the world when it was most open to outside forces as well as to the flow and acceptance of people from beyond the country's borders, and sank into stagnation when it conversely shut itself off from the greater world. This paper will argue that such views, which made him a pariah of official discourse and a hero to the counter culture, gained currency in the public sphere because of the force of his arguments, his effective use of rhetorical strategies, and his adept deployment of linguistic devices that he had developed as a prose writer.