The UN Secretary-General defines Rule of Law as “a principle of governance in which all persons, institutions and entities, public and private, including the State itself, are accountable to laws that are publicly promulgated, equally enforced and independently adjudicated, and which are consistent with international human rights norms and standards." (
http://www.un.org/en/ruleoflaw/index.shtml)
The World Justice Project gives four principles that define Rule of Law: the government and its officials and agents are accountable under the law; the laws are clear, publicized, stable and fair, and protect fundamental rights, including the security of persons and property; the process by which the laws are enacted, administered and enforced is accessible, fair and efficient; access to justice is provided by competent, independent, and ethical adjudicators, attorneys or representatives, and judicial officers who are of sufficient number, have adequate resources, and reflect the makeup of the communities they serve. (
http://www.worldjusticeproject.org/rule-of-law-index)
At the organization level, the first principle explains the criticality of top management/leadership equally adhering to the ethics code. That is why the Sarbanes-Oxley Act specifies adoption of the ethics code by senior executives (reference Section 406).