<P> The concept of natural law is related to the concept of natural rights . Natural law first appeared in ancient Greek philosophy , and was referred to by Roman philosopher Cicero . It was subsequently alluded to in the Bible , and then developed in the Middle Ages by Catholic philosophers such as Albert the Great and his pupil Thomas Aquinas . During the Age of Enlightenment , the concept of natural laws was used to challenge the divine right of kings , and became an alternative justification for the establishment of a social contract , positive law , and government -- and thus legal rights -- in the form of classical republicanism . Conversely , the concept of natural rights is used by others to challenge the legitimacy of all such establishments . </P>
<P> The concept of natural law is related to the concept of natural rights . Natural law first appeared in ancient Greek philosophy , and was referred to by Roman philosopher Cicero . It was subsequently alluded to in the Bible , and then developed in the Middle Ages by Catholic philosophers such as Albert the Great and his pupil Thomas Aquinas . During the Age of Enlightenment , the concept of natural laws was used to challenge the divine right of kings , and became an alternative justification for the establishment of a social contract , positive law , and government -- and thus legal rights -- in the form of classical republicanism . Conversely , the concept of natural rights is used by others to challenge the legitimacy of all such establishments . </P>
who first described the idea of natural rights
who first described the idea of natural rights
ancient Greek philosophy
ancient Greek philosophy