Final answer:
Milton compares Satan to mythological giants to emphasize his rebellious nature and grand ambitions, reflecting the giants' defiance of the divine order in their own myths.
Step-by-step explanation:
Milton compares Satan to mythological giants primarily to emphasize Satan's rebellious nature and ambitions. By drawing parallels between Satan and figures known for their immense size and often for challenging the gods, Milton evokes a sense of grandeur and defiance that aligns with Satan's character in Paradise Lost. This comparison underscores Satan's powerful desire to oppose the divine order, much like mythological giants were known to do in their respective narratives. Furthermore, mythological allusions enrich Milton's epic poem, adding depth and resonance to the portrayal of its central antagonist.