American theorists sought for some element of fraternity some suggestion of bonds uniting man and man. Yet the Enlightenment doctrines made the object of that search difficult to attain. Reason, conceived as the “servant of the passions,” could not unite them. The empiricism and individualism of the new theories tended to portray man as radically isolated from his fellows. If some bond of brotherhood were to be discovered among men, it would have to be found in the “natural” qualities of mankind, the senses and “instincts” with which men were born.
Wilson Carey McWilliams, The Idea of Fraternity in America, 173-174