This is the account John Carter gives of his exploration of Mars. He first encounters a race of nomadic warriors. Their only art is the art of war. They kill offspring showing weakness at birth. The strong are only educated to speak. A reckless courage & great endurance of pain are their only virtues.
Communism regarding family is their way; incest is inevitable & the entire race is devoid of eroticism. They call themselves a hoard & their only sense of unity comes in fighting common enemies. Otherwise, they kill each other for amusement or personal gain. Communism regarding property is therefore inevitable, except for weapons.
Mars is the god of war. The nomadic race accept Carter as a chieftain because he fights & kills by their conventions, which set minimum limits on anger. Military skill is universal. As hunting suggests, all animals are spurred by necessity. Spirited men admire such excellence spontaneously. Carter resembles these savages not only because his only art is an art of war, but also because of his great endurance & attendant stubbornness. Perhaps anger is in a sense universal, for all that lives will live & so must defend itself.
Carter later encounters the humans, who are settled in their cities, & whose advanced civilization is brimful of sciences & arts. Of course, they are also warriors & they love flying in their crafts as much as the nomads love crawling on the earth & hiding among ruins. The cities fight each other & their entire race seems in danger of suicide. The race is red-skinned & they wear elaborate tattoos. Like every other creature on Mars, they go around mostly naked, having no notion of shame.
Nobility, particularly the nobility of sacrifice, is the question that has to be settled between Carter & the red Martians, specifically their princess, whom he saves. Carter has no cause, because his beloved Virginia lost the Civil War & his beloved family was killed. Devoid of purpose, his spiritedness turns to exploring the wilderness & love of gold. But hatred of injustice causes him to take up arms again. Ultimately, this is the injustice of necessity: death, threatening to extinguish Mars.
At the end, the hero meets the poet & admits he has lied to him in his writings. Apparently, the poet cannot be merely told the truth, for he is not a detached witness, but a help to the hero to protect himself from the force of necessity. The hero explains himself: if his body is allowed to be destroyed, then his spirit also must perish. In his ministry to the hero, the poet is admonished to love women & adventure & to write a books.
A fine adventure movie. Go see it.