There is a sense of will in Achilles' gentleness towards the man, and his willingness to touch Priam's sleeve that night. In other words, human and divine reconciliation and pity is not simply a law, humans must accept the will of the gods, but they are also capable of choosing to add or subtract the misery of the world by showing pity to their fellow humans. Odysseus' cleverness, although aided by the gods, is also partly drawn from his own resourcefulness and character, as well as merely because Athena helps him. Achilles makes what is said to be the greatest gift to Priam, that of Hector's body. In Greek custom, gifts were customary to give to visitors. With such a gift, Achilles gives up his determination to mourn Patroclus for all time, and becomes the 'perfect' host who puts his own needs aside for the needs of his guest. In contrast, the suitors abuse the notions of hospitality of the gods, eating all of Odysseus' food and wine, and paying court to his wife to convince her that her husband is dead and she should marry again. The vulnerability of humankind is most evident when one is a stranger in a strange land, hence the need to protect one's guest, even if one's guest is an enemy -- thus by acknowledging human vulnerability, one acknowledges the will of the gods again, but still shows one's own strength of character and refusal to add to the miseries of Zeus' jar.

A combination of deference and will is what is necessary to achieve the ultimate goal, the ability to carry on a legacy through one's son. This is validated from Book I on in the "Odyssey" as Telemachus seeks his father, to bring order once again to the kingdom. Telemachus has a life-fulfilling...

He is a son who is a living legacy of his father, who will carry on his father's name if he can bring the kingdom to right and drive the suitors out. In contrast, Priam has a dead legacy -- he is grateful to gain Hector's body once again, but his other sons Paris and Astyanax will not replace the greatness of Hector, and he is burying his child before his time. Likewise, Peleus and Achilles do not have an equal fulfillment of a legacy that will be carried on. This is not because Odysseus is better than the other fathers, or more pious, but because of the capricious will of the gods.
Thus survival is a mix of reliance upon good hospitality, one's piety and luck, and also one's destiny. Odysseus is more pious and beloved by Athena than his crew, thus he survives and they do not -- however, Achilles is not more pious than Hector, yet it is he who bestows the body of Hector upon the gods. Even the gods themselves doubt about the best way to extract Hector's body. Thus, rather than a coherent statement about the folly of humankind that develops from "Iliad" to "Odyssey," it would be more apt to say that the books have similar themes, but cannot come to a strict resolution about the single, unified 'right' way to behave in a world where one can never be sure of one's fate, only be sure that the best way to live is not to add more misery through impiety and violence towards one's host or guest in an already frustrating world.

Works Cited

Homer. "The Iliad." Trans. Robert Fagles. New York: Penguin, 1990.

Homer. "The Odyssey." Trans. Robert Fagles. New York: Penguin, 1996