 His sources for his belief were many. The obvious sources include sources such as the American founding documents, popular intellectuals, such as Ralph Waldo Emerson, and his colleagues and acquaintances in the American Abolition movement, and the allies he encountered abroad; a particular source of his conception of natural law theory was George Combe’s The Constitution of Man, from 1834 (in Van Wyhe 2004). However, given the numerous religious references in his speeches and writings, and his drawing on the language of the King James Bible, and the rhetoric of manifest destiny, a primary source for his employment of the idea of natural law seems to be his adoption of the American Protestantism of the Second Great Awakening, with its democratic, republican, and generally independent spirit.