Lewis believed that Thomas Paine was the true author of the Declaration of Independence, and made his case for this theory in his 1947 book "Thomas Paine, Author of the Declaration of Independence". His other noteworthy publications included "The Ten Commandments" (1946), a lengthy justification for atheism, and "An Atheist Manifesto" (1954), published at the height of the Cold War to dispute popular ideas that atheism was un-American. He deeply recognized the meaning of Paine's ideas for establishing of the USA and acquiring its independence from Great Britain. His first attempt to create a committee in order to include Paine's name in the Hall of Fame of New York was made in 1935 but was interrupted by the World War II. He appreciated Paine a lot for his ideas of "common man" and the freedom of slaves in the USA,