Columbia subject headings:
Harvard subject headings:
Condillac, Etienne Bonnot de, 1714-1780.
Language and languages--Philosophy--History--18th century
Rousseau, Jean-Jacques, 1712-1778
Vico, Giambattista, 1668-1744.
Princeton subject headings:
Language and languages--Origin--History--18th century.
Language and languages--Philosophy--History--18th century.