Theseus is a great leader. In war he is brave and daring, but he does not risk the lives of his soldiers unnecessarily. In peace he tries to act in the best interests of the people. Good leadership brings loyalty, and the loyalty that he inspires in the Companions saves his life in his battle with Xanthos. Minos in Crete has lost touch with the gods and his people, and as he lives, Asterion gains power. At the end of his life, Minos helps Theseus and again becomes worthy of his title as king. Asterion rules without a legitimate title, and is not responsible to anyone. He does not pay heed to the gods or to other men but simply desires power. Aigeus is a good leader, but also exemplifies the difficulty of remaining a good leader. Many years spent trying to rule properly can wear someone out, and there is always more to do. But the book suggests that a good leader always tries, and is even willing to sacrifice himself for the people, if necessary.
Theseus believes that justice must be carried out, and the voice of Poseidon tells him the right thing to do. Justice is important because the gods will punish injustices. Although Theseus kills many people in his journeys and upsets many customs, he never does so without reasons. For example, in Eleusis he changes the traditional matrimonial rule and gives men some power. The queen tries to have him killed because she fears his intervention, but, as he tells her, he would never stop worship of Mother Dia. Theseus weighs all of his decisions, and when he does not know what to do he calls to Poseidon for help. When Theseus asks the gods for a sign, he searches his soul and mind to know the right thing to do. When Poseidon tells him that he must go to Crete, Theseus goes, notwithstanding his reluctance. Although it likely means he will die, he goes with a light heart, because he believes his action is just.
Theseus's belief that he is the son of Poseidon causes him to try to be worthy of the god. Many different types of belief appear in the novel. The Minyans belief that the Mother is supreme, and they have a whole host of rituals in her honor. The Hellenes, on the other hand, believe in Zeus, Poseidon, Apollo and the other gods in addition to the Mother. These societies therefore appear very different, but the function of belief is the same in all of them. It is the belief in their deities that brings meaning to the people's lives. They believe that their rituals can cleanse them from wrongdoing, renew the land, or aid them in need, and therefore when the rituals are performed they feel calm and reassured. Sometimes the different beliefs clash, such as in Eleusis, when the Queen tries to kill Theseus because he would change the rituals. But Theseus does not really upset the belief of the people, he simply alters where they put that belief, and in doing so shifts the entire hierarchy of the kingdom. Belief is critical to Theseus, because he believes that Poseidon speaks to him. In times of crisis Theseus prays to the god for guidance, and he thinks that he gets a message from the god. Afterward, Theseus is always content with the choice he makes and does not question his decision. Theseus does not even really consider his decisions to be his own—he simply lays out the options and lets the god decide.
Theseus values his honor more than he values his life. When Asterion insults him and treats him like a slave, Theseus wishes nothing more than to have revenge upon him. But Asterion is not an honorable man. He wishes for power, and does not consider honor to be worth anything. Because none of them have any honor, they will not stand up to Asterion. The novel shows the different outcomes for the honorable and dishonorable. Those who do not have honor will value their lives and their wealth above all else, and therefore run the risk of becoming slaves. However, those who have honor will always be free. Even Asterion, though he is most powerful of the nobles, is a slave to power.
Rituals play a recurring role in The King Must Die. They demonstrate the similarities and differences between cultures. Not only do the varying rituals elucidate the different deities that people believe in, they also indicate what people's lives are like. In Troizen and Eleusis, where the people depend upon good harvests and good weather for their survival, the rituals are taken very seriously. In Crete, on the other hand, where the nobles are incredibly wealthy and collect many taxes from other areas, the rituals are lax—Ariadne knows ahead of time what she will prophesy. The rituals demonstrate the degree to which the people are removed from necessity, and they also help unite and revitalize the people. Therefore those societies that lose touch with the rituals, although they will be more prosperous, will also be more likely to decay and come to ruin.
The gods act frequently in Theseus's story, in great and small ways. Yet Renault's book is an historical novel, and she clearly is not suggesting that these goods actually exist or play a role in the events of the world. Rather, the gods symbolize nature. Mother Dia, worshipped by everyone but to the Minyans the only true deity, is very reminiscent of Mother Nature. She is the living earth, and is active all the time. Of the gods that the Hellenes worship, Poseidon, the god of the sea, is the most prominent. The seas are often unpredictable and can be very harsh, and it is easy to see how they could be conceived of as controlled by a higher power. Poseidon is also the earth-shaker, responsible for earthquakes. Theseus is able to foresee earthquakes, but he thinks that he feels the god's anger rather than some natural effect. Such spectacular and destructive occurrences seem like they should be the work of a higher power. The gods are nature personified, and Renault shows us how easily it is to believe in them.
King Pittheus explains moira to young Theseus as "the finished shape of our fate." Pittheus says that we are born to seek out moira. Unlike our fate, which is set out before us beyond our control, moira symbolizes our destiny, that which we make of ourselves. We will all die, and we do not have so long to live, but what we do with the time we have—that is our moira. We do have a fate, and we cannot escape it, but the gods do not control what we do within the bounds of that fate. Our moira is what we are fated to seek out. Throughout the book, moira is used almost as an explanatory device. When Theseus kills Kerkyon, and becomes King in Eleusis, he knows that he was fated to do so, but he also knows that it is not his moira to be in Eleusis. Moira is our freedom to live despite the certainty of dying.