"... one of the most characteristic and compelling features of [Tolkien's] books is their ability to evoke a palpable sense of untold stories and unexplored vistas, of landscapes glimpsed at the edges of other foregrounded pictures, that are at once suggestive, enticing and unbreachably distant: we desire to go there (to hear the story), and at the same time know it is, for now, unbearably beyond our reach - like the luminous countries glimpsed through windows in fifteenth-century Italian paintings. The means Tolkien uses to achieve this effect are, most usually, names: unglossed but resonant, with a felt (because real) internal consistency and meaning. This is the fruit of the linguistic background of his tales; the languages, he insisted, presupposed a world they described, and so by devising the one he necessarily created the other. This is exactly the function that technical philology had for Tolkien and for scholars like him: words and phrases implied a reality, a world inhabited by their speakers and best described by these very words."
From Tolkien by Raymond Edwards - which I warmly recommend.