During the 18th century conjectural history, based on a mix of linguistics and anthropology, on the topic of both the origin and progress of language and society was fashionable. These thinkers contributed to the construction of academic paradigms in which some languages were labelled "primitive" relative to the English language. Within this paradigm a primitive people could be discerned by their primitive language, as in the case of Hugh Blair who argued that Native Americans gesticulated wildly to compensate for poor lexicon of their primitive language. Around the same time, James Burnett authored a 6 volume treatise that delved more deeply into the matter of "savage languages". Other writers theorized that Native American languages were "nothing but the natural and instinctive cries of the animal" without grammatical structure. The thinkers within this paradigm connected themselves with the Greeks and Romans, viewed as the only civilized persons of the ancient world, a view articulated by Thomas Sheridan who compiled an important 18th century pronunciation dictionary: "It was to the care taken in the cultivation of their languages, that Greece and Rome, owed that splendor, which eclipsed all the other nations of the world".