Symbolism, Imagery, Allegory
Much of the symbolism in Antigone lies in the characters themselves. Antigone and Creon represent a number of opposing forces: male vs. female, family ties vs. civic duty, man vs. nature, and man's laws vs. the laws of the gods. Also, there's the blind prophet Teiresias who could be seen as representing the will of the gods. Check out the "Character Analysis" section for more details on the larger symbolism of the characters.