As a scholar, Mencken is known for "The American Language", a multi-volume study of how the English language is spoken in the United States. As an admirer of the German philosopher Friedrich Nietzsche, he was an outspoken opponent of organized religion, theism, populism, and representative democracy, the last of which he viewed as a system in which inferior men dominated their superiors. Mencken was a supporter of scientific progress and was critical of osteopathy and chiropractic. He was also an open critic of economics.