The 1960s marked a major shift in constitutional interpretation, as the Warren Court continued the process of the incorporation of the Bill of Rights in which the provisions of the first ten amendments to the US Constitution were applied to the states. Warren saw the Bill of Rights as a codification of "the natural rights of man" against the government and believed that incorporation would bring the law "into harmony with moral principles." When Warren took office, most of the provisions of the First Amendment already applied to the states, but the vast majority of the Bill of Rights applied only to the federal government. The Warren Court saw the incorporation of the remaining provisions of the First Amendment as well as all or part of the Fourth, Fifth, Sixth, and Eighth Amendments. The Warren Court also handed down numerous other important decisions regarding the Bill of Rights, especially in the field of criminal procedure.