What is the source of law’s legitimacy for Antigone and Creon?

The confrontation between Antigone and her uncle Creon (the ruler of Thebes) begins with the demise of her two brothers Eteocles and Polyneices. Since Creon was on the side of Eteocles during the combat between the two brothers, he decrees to honor him in death.  In sharp contrast he decrees that Polyneices be left rotting in the battle field sans a proper burial.  This is the highest form of punishment in ancient Greek and its evocation is a measure of Creon’s hostility toward Polyneices.  In Creon’s own view, what legitimizes his decree is his authority as the supreme ruler of Thebes.  He performs very little moral deliberation before setting his order to execution.

But Polyneices’ beloved sister Antigone is a balanced, intellectual and humane person (as evidenced from allusions in the play). Her love for her brother impels her to bury him properly. Though this action would invoke the wrath of Creon and jeopardize her life, her humanity and love supersedes all other considerations.  Antigone believes that though she may die as a consequence of her rightful action, she anticipates being rewarded for it in the afterlife. Hence, what legitimizes her actions is moral fortitude that has a founding on ancient theology.

In sharp contrast, Creon is so consumed by his authority that his decisions lack elaborate moral scruples.  His stubbornness will tragically lead to the death of his own son Haemon, his beloved wife Eurydice and also that of his niece Antigone. Through these great losses he learns a lesson in humility and realizes all too late that one cannot become a law onto oneself.  In other words, even the supreme command of the King will have to submit to the natural laws of humanitarian justice.

Reference:

Segal, Charles (1999). Tragedy and Civilization: An Interpretation of Sophocles. Norman, OK: University of Oklahoma Press. p.266. ISBN 978-0-8061-3136-8