The functional interpretation of the term "rule of law", consistent with the traditional English meaning, contrasts the "rule of law" with the "rule of man." According to the functional view, a society in which government officers have a great deal of discretion has a low degree of "rule of law", whereas a society in which government officers have little discretion has a high degree of "rule of law". Upholding the rule of law can sometimes require the punishment of those who commit offenses that are justifiable under natural law but not statutory law. The rule of law is thus somewhat at odds with flexibility, even when flexibility may be preferable.

According to the functional interpretation, what principle is opposite of the rule of man?