The Iliad is the story of a brief event in the ninth year of the war (which the Greeks claim lasted ten years); the great hero Achilles is offended when the leader of the Greeks, Agamemnon, takes a slave girl Achilles has been awarded. Achilles withdraws from the battle and prays to his mother, Thetis, a goddess, to turn the tide of battle against the Greeks. The gods grant Achilles his prayer, and he does not return to battle until his best friend is killed by the great Trojan hero, Hector. Achilles throws himself into the battle, fights Hector, and kills him; in a final gesture of contempt, he drags Hector's lifeless body around the walls of Troy. If there is a "theme" to the epic, it is "Achilles choice." Achilles has been offered a choice, either to be a great and famous hero in war and die young (Achilles does die in Troy when a poison arrow strikes him in the ankle), or to live a long, happy life without any lasting fame whatsoever. Although Achilles initially chooses not to die young, the death of his friend forces him to make the choice that will make him famous for all time, but tragically dead at a young age.
The Odyssey is the story of the homecoming of another of the great Greek heroes at Troy, Odysseus. Unlike Achilles, Odysseus is not famous for his great strength or bravery, but for his ability to deceive and trick (it is Odysseus's idea to take Troy by offering the citizens a large wooden horse filled, unbeknownst to the Trojans, with Greek soldiers). He is the anthropos polytropos, the "man of many ways," or the "man of many tricks." His homecoming has been delayed for ten years because of the anger of the gods; finally, in the tenth year, he is allowed to go home. He hasn't been misspending his time, though; for most of the ten years he has been living on an island with the goddess Kalypso, who is madly in love with him. Odysseus is offered a choice, much like Achilles's choice: he may either live on the island with Kalypso and be immortal like the gods, or he may return to his wife and his country and be mortal like the rest of us. He chooses to return, and much of the rest of the work is a long exposition on what it means to be "mortal." If the Odyssey has a discernible theme, it is the nature of mortal life, why any human being would, if offered the chance to be a god, still choose to be mortal. This choice becomes particularly problematic when Odysseus, in Book XI, meets the ghost of Achilles in the Underworld; Odysseus remarks to Achilles how all the shades of the dead must worship and serve Achilles, but Achilles replies that he would rather be the meanest and most obscure slave of the poorest landholder than be the most famous of the dead. If being dead is so awful, what is it about being human that makes up for the infinite suffering that attends our deaths? As part of this question concerning the nature of human life, much of the book deals with the nature of human civilization and human savagery.
The Greeks in general regard Homer's two epics as the highest cultural achievement of their people, the defining moment in Greek culture which set the basic Greek character in stone. Throughout antiquity, both in Greece and Rome, everything tended to be compared to these two works; events in history made sense when put in the light of the events narrated in these two works.
There are two very important words repeatedly used throughout the Homeric epics: honor and virtue or greatness The latter term is perhaps the most reiterated cultural and moral value in Ancient Greece and means something like achieving, morally and otherwise, your greatest potential as a human being. The reward for great honor and virtue is fame (kleos ), which is what guarantees meaning and value to one's life. Dying without fame (akleos ) is generally considered a disaster, and the warriors of the Homeric epics commit the most outrageous deeds to avoid dying in obscurity or infamy (witness Odysseus's absurd insistence on telling Polyphemos his name even though this will bring disaster on him and his men). The passage from Odyssey XI discussed above presents Achilles's final judgement on kleos and its value when he tells Odysseus that he would rather be alive and the most obscure human on earth than dead and famous.
"The Great Wanderings," from which these extracts are taken, make up Books IX-XI of the Odyssey ; in this part of the epic, Odysseus narrates to his hosts, the Phaiakians, who have rescued him from the sea after he leaves Kalypso's island, about his adventures following the Trojan War and how he came to be shipwrecked alone on the island with Kalypso. It is this part of the story you are probably most familiar with and have encountered in some form or another, if only in the Kirk Douglas movie. If there is a general idea animating the account of these wanderings, it is the nature of civilization and ordered society. Most of the fabulous events, especially the story of Polyphemos, in some way deal with the values that underlie the early Greek notion of order and civility, as well as those values that underlie the heroic code.